Rambda

addProp<T extends object, P extends PropertyKey, V extends unknown>(
	prop: P,
	value: V
): (obj: T) => MergeTypes<T & Record<P, V>>;

export function addProp(key, value) {
  return obj => ({ ...obj, [key]: value })
}

import { addProp } from './addProp.js'

test('happy', () => {
	const result = addProp('a', 1)({ b: 2 })
	const expected = { a: 1, b: 2 }

	expect(result).toEqual(expected)
})

import { addProp, pipe } from 'rambda'

it('R.addProp', () => {
	const result = pipe({ a: 1, b: 'foo' }, addProp('c', 3))
	result.a // $ExpectType number
	result.b // $ExpectType string
	result.c // $ExpectType number
})

addPropToObjects<
  T extends object,
  K extends string,
  R
>(
	property: K,
  fn: (input: T) => R
): (list: T[]) => MergeTypes<T & { [P in K]: R }>[];

import { mapFn } from './map.js'

export function addPropToObjects (
	property, 
	fn
){
	return listOfObjects => mapFn(
		(obj) => ({
			...(obj),
			[property]: fn(obj)
		}), 
		listOfObjects
	)
}

import { pipe } from './pipe.js'
import { addPropToObjects } from './addPropToObjects.js'

test('R.addPropToObjects', () => {
		let result = pipe(
			[
				{a: 1, b: 2},
				{a: 3, b: 4},
			],
			addPropToObjects(
				'c',
				(x) => String(x.a + x.b),
			)
		)
		expect(result).toEqual([
			{ a: 1, b: 2, c: '3' },
			{ a: 3, b: 4, c: '7' },
		])
})

import { addPropToObjects, pipe } from 'rambda'

it('R.addPropToObjects', () => {
		let result = pipe(
			[
				{a: 1, b: 2},
				{a: 3, b: 4},
			],
			addPropToObjects(
				'c',
				(x) => String(x.a + x.b),
			)
		)
		result // $ExpectType { a: number; b: number; c: string; }[]
})

all<T>(predicate: (x: T) => boolean): (list: T[]) => boolean;

export function all(predicate) {
  return list => {
    for (let i = 0; i < list.length; i++) {
      if (!predicate(list[i])) {
        return false
      }
    }

    return true
  }
}

import { all } from './all.js'

const list = [0, 1, 2, 3, 4]

test('when true', () => {
  const fn = x => x > -1

  expect(all(fn)(list)).toBeTruthy()
})

test('when false', () => {
  const fn = x => x > 2

  expect(all(fn)(list)).toBeFalsy()
})

import * as R from 'rambda'

describe('all', () => {
  it('happy', () => {
    const result = R.pipe(
      [1, 2, 3],
      R.all(x => {
        x // $ExpectType number
        return x > 0
      }),
    )
    result // $ExpectType boolean
  })
})

allPass<F extends (...args: any[]) => boolean>(predicates: readonly F[]): F;

export function allPass(predicates) {
  return input => {
    let counter = 0
    while (counter < predicates.length) {
      if (!predicates[counter](input)) {
        return false
      }
      counter++
    }

    return true
  }
}

import { allPass } from './allPass.js'
import { filter } from './filter.js'
import { pipe } from './pipe.js'

const list = [
  [1, 2, 3, 4],
  [3, 4, 5],
]
test('happy', () => {
  const result = pipe(list, filter(allPass([x => x.includes(2), x => x.includes(3)])))
  expect(result).toEqual([[1, 2, 3, 4]])
})

test('when returns false', () => {
  const result = pipe(list, filter(allPass([x => x.includes(12), x => x.includes(31)])))
  expect(result).toEqual([])
})

import * as R from 'rambda'

describe('allPass', () => {
  it('happy', () => {
    const list = [
      [1, 2, 3, 4],
      [3, 4, 5],
    ]
    const result = R.pipe(list, R.map(R.allPass([
			(x) => x.length > 2,
			(x) => x.includes(3)
		])))
    result // $ExpectType boolean[]
  })
})

any<T>(predicate: (x: T) => boolean): (list: T[]) => boolean;

export function any(predicate) {
  return list => {
    let counter = 0
    while (counter < list.length) {
      if (predicate(list[counter], counter)) {
        return true
      }
      counter++
    }

    return false
  }
}

import { any } from './any.js'

const list = [1, 2, 3]

test('happy', () => {
  expect(any(x => x > 2)(list)).toBeTruthy()
})

import { any, pipe } from 'rambda'

it('R.any', () => {
  const result = pipe(
    [1, 2, 3],
    any(x => {
      x // $ExpectType number
      return x > 2
    }),
  )
  result // $ExpectType boolean
})

anyPass<T, TF1 extends T, TF2 extends T>(
  predicates: [(a: T) => a is TF1, (a: T) => a is TF2],
): (a: T) => a is TF1 | TF2;
anyPass<T, TF1 extends T, TF2 extends T, TF3 extends T>(
  predicates: [(a: T) => a is TF1, (a: T) => a is TF2, (a: T) => a is TF3],
): (a: T) => a is TF1 | TF2 | TF3;
anyPass<T, TF1 extends T, TF2 extends T, TF3 extends T>(
  predicates: [(a: T) => a is TF1, (a: T) => a is TF2, (a: T) => a is TF3],
): (a: T) => a is TF1 | TF2 | TF3;
anyPass<T, TF1 extends T, TF2 extends T, TF3 extends T, TF4 extends T>(
  predicates: [(a: T) => a is TF1, (a: T) => a is TF2, (a: T) => a is TF3, (a: T) => a is TF4],
): (a: T) => a is TF1 | TF2 | TF3 | TF4;
...
...

export function anyPass(predicates) {
  return input => {
    let counter = 0
    while (counter < predicates.length) {
      if (predicates[counter](input)) {
        return true
      }
      counter++
    }

    return false
  }
}

import { anyPass } from './anyPass.js'

test('happy', () => {
  const rules = [x => typeof x === 'string', x => x > 10]
  const predicate = anyPass(rules)
  expect(predicate('foo')).toBeTruthy()
  expect(predicate(6)).toBeFalsy()
})

test('happy', () => {
  const rules = [x => typeof x === 'string', x => x > 10]

  expect(anyPass(rules)(11)).toBeTruthy()
  expect(anyPass(rules)(undefined)).toBeFalsy()
})

const obj = {
  a: 1,
  b: 2,
}

test('when returns true', () => {
  const conditionArr = [val => val.a === 1, val => val.a === 2]

  expect(anyPass(conditionArr)(obj)).toBeTruthy()
})

test('when returns false', () => {
  const conditionArr = [val => val.a === 2, val => val.b === 3]

  expect(anyPass(conditionArr)(obj)).toBeFalsy()
})

test('with empty predicates list', () => {
  expect(anyPass([])(3)).toBeFalsy()
})

import { anyPass, filter } from 'rambda'

describe('anyPass', () => {
  it('issue #604', () => {
    const plusEq = (w: number, x: number, y: number, z: number) => w + x === y + z
    const result = anyPass([plusEq])(3, 3, 3, 3)

    result // $ExpectType boolean
  })
  it('issue #642', () => {
    const isGreater = (num: number) => num > 5
    const pred = anyPass([isGreater])
    const xs = [0, 1, 2, 3]

    const filtered1 = filter(pred)(xs)
    filtered1 // $ExpectType number[]
    const filtered2 = xs.filter(pred)
    filtered2 // $ExpectType number[]
  })
  it('functions as a type guard', () => {
    const isString = (x: unknown): x is string => typeof x === 'string'
    const isNumber = (x: unknown): x is number => typeof x === 'number'
    const isBoolean = (x: unknown): x is boolean => typeof x === 'boolean'

    const isStringNumberOrBoolean = anyPass([isString, isNumber, isBoolean])

    const aValue: unknown = 1

    if (isStringNumberOrBoolean(aValue)) {
      aValue // $ExpectType string | number | boolean
    }
  })
})

append<T>(el: T): (list: readonly T[]) => T[];
append<T>(el: T): (list: T[]) => T[];

import { cloneList } from './_internals/cloneList.js'

export function append(x) {
  return list => {
    const clone = cloneList(list)
    clone.push(x)

    return clone
  }
}

import { append } from './append.js'

test('happy', () => {
  expect(append('tests')(['write', 'more'])).toEqual(['write', 'more', 'tests'])
})

test('append to empty array', () => {
  expect(append('tests')([])).toEqual(['tests'])
})

import { append, pipe, prepend } from 'rambda'

const listOfNumbers = [1, 2, 3]

describe('R.append/R.prepend', () => {
  it('happy', () => {
    const result = pipe(listOfNumbers, append(4), prepend(0))
    result // $ExpectType number[]
  })
  it('with object', () => {
    const result = pipe([{ a: 1 }], append({ a: 10 }), prepend({ a: 20 }))
    result // $ExpectType { a: number; }[]
  })
})

ascend<T>(fn: (obj: T) => Ord): (a: T, b: T)=> Ordering;

export function createCompareFunction(a, b, winner, loser) {
  if (a === b) {
    return 0
  }

  return a < b ? winner : loser
}

export function ascend(getFunction) {
	return (a, b) => {
  const aValue = getFunction(a)
  const bValue = getFunction(b)

  return createCompareFunction(aValue, bValue, -1, 1)
}
}

import { ascend } from './ascend.js'
import { descend } from './descend.js'
import { sort } from './sort.js'

test('ascend', () => {
  const result = sort(
    ascend(x => x.a))(
    [{a:1}, {a:3}, {a:2}],
  )
  expect(result).toEqual([{a:1}, {a:2}, {a:3}])
})

test('descend', () => {
  const result = sort(
    descend(x => x.a))(
    [{a:1}, {a:3}, {a:2}],
  )
  expect(result).toEqual([{a:3}, {a:2}, {a:1}])
})

import { pipe, ascend, sort } from 'rambda'

it('R.ascend', () => {
	const result = pipe(
		[{a:1}, {a:2}],
		sort(ascend(x => x.a))
	)
	result // $ExpectType { a: number; }[]
})

assertType<T, U extends T>(fn: (x: T) => x is U) : (x: T) => U;

export function assertType(fn) {
  return (x) => {
    if (fn(x)) {
      return x
    }
    throw new Error('type assertion failed in R.assertType')
  }
}

import { assertType } from './assertType.js'
import { pipe } from './pipe.js'

test('happy', () => {
  const result = pipe(
		[1, 2, 3],
		assertType((x) => x.length === 3),
	)
	expect(result).toEqual([1, 2, 3])
})

test('throw', () => {
	expect(() => {
		pipe(
			[1, 2, 3],
			assertType((x) => x.length === 4),
		)
	}).toThrow('type assertion failed in R.assertType')
})

import { pipe, assertType } from 'rambda'

type Book = {
	title: string
	year: number
}

type BookToRead = Book & {
	bookmarkFlag: boolean
}

function isBookToRead(book: Book): book is BookToRead {
	return (book as BookToRead).bookmarkFlag !== undefined 
}

it('R.assertType', () => {
	const result = pipe(
		{ title: 'Book1', year: 2020, bookmarkFlag: true },
		assertType(isBookToRead),
	)
	result // $ExpectType BookToRead
})

checkObjectWithSpec<T>(spec: T): <U>(testObj: U) => boolean;

export function checkObjectWithSpec(conditions) {
  return input => {
    let shouldProceed = true
    for (const prop in conditions) {
      if (!shouldProceed) {
        continue
      }
      const result = conditions[prop](input[prop])
      if (shouldProceed && result === false) {
        shouldProceed = false
      }
    }

    return shouldProceed
  }
}

import { checkObjectWithSpec } from './checkObjectWithSpec.js'
import { equals } from './equals.js'

test('when true', () => {
  const result = checkObjectWithSpec({
    a: equals('foo'),
    b: equals('bar'),
  })({
    a: 'foo',
    b: 'bar',
    x: 11,
    y: 19,
  })

  expect(result).toBeTruthy()
})

test('when false | early exit', () => {
  let counter = 0
  const equalsFn = expected => input => {
    counter++

    return input === expected
  }
  const predicate = checkObjectWithSpec({
    a: equalsFn('foo'),
    b: equalsFn('baz'),
  })
  expect(
    predicate({
      a: 'notfoo',
      b: 'notbar',
    }),
  ).toBeFalsy()
  expect(counter).toBe(1)
})

import { checkObjectWithSpec, equals } from 'rambda'

describe('R.checkObjectWithSpec', () => {
  it('happy', () => {
    const input = {
      a: 'foo',
      b: 'bar',
      x: 11,
      y: 19,
    }
    const conditions = {
      a: equals('foo'),
      b: equals('bar'),
    }
    const result = checkObjectWithSpec(conditions)(input)
    result // $ExpectType boolean
  })
})

compact<T>(list: T[]): Array<StrictNonNullable<T>>;
compact<T extends object>(record: T): {
  [K in keyof T as Exclude<T[K], null | undefined> extends never
    ? never
    : K
  ]: Exclude<T[K], null | undefined>
};

import { isArray } from './_internals/isArray.js'
import { reject } from './reject.js'
import { rejectObject } from './rejectObject.js'

const isNullOrUndefined = x => x === null || x === undefined

export function compact(input){
	if(isArray(input)){
		return reject(isNullOrUndefined)(input)
	}
	return rejectObject(isNullOrUndefined)(input)
}

import { compact } from './compact.js'
import { pipe } from './pipe.js'

test('happy', () => {
  const result = pipe(
		{
			a: [ undefined, 'a', 'b', 'c'],
			b: [1,2, null, 0, undefined, 3],
			c: { a: 1, b: 2, c: 0, d: undefined, e: null, f: false },
		},
		x => ({
			a: compact(x.a),
			b: compact(x.b),
			c: compact(x.c)
		})
	)
	expect(result.a).toEqual(['a', 'b', 'c'])
	expect(result.b).toEqual([1,2,0,3])
	expect(result.c).toEqual({ a: 1, b: 2,c:0, f: false })
})

import { compact, pipe } from 'rambda'

it('R.compact', () => {
		let result = pipe(
			{
				a: [ undefined, '', 'a', 'b', 'c', null ],
				b: [1,2, null, 0, undefined, 3],
				c: { a: 1, b: 2, c: 0, d: undefined, e: null, f: false },
			},
			x => ({
				a: compact(x.a),
				b: compact(x.b),
				c: compact(x.c)
			})
		)

		result.a // $ExpectType string[]
		result.b // $ExpectType number[]
		result.c // $ExpectType { a: number; b: number; c: number; f: boolean; }
})

complement<T extends any[]>(predicate: (...args: T) => unknown): (...args: T) => boolean;

export function complement(fn) {
  return (...input) => !fn(...input)
}

import { complement } from './complement.js'

test('happy', () => {
  const fn = complement(x => x.length === 0)

  expect(fn([1, 2, 3])).toBeTruthy()
})

test('with multiple parameters', () => {
  const between = (a, b, c) => a < b && b < c
  const f = complement(between)
  expect(f(4, 5, 11)).toBeFalsy()
  expect(f(12, 2, 6)).toBeTruthy()
})

import { complement } from 'rambda'

describe('R.complement', () => {
  it('happy', () => {
    const fn = complement((x: number) => x > 10)
    const result = fn(1)
    result // $ExpectType boolean
  })
})

concat<T>(x: T[]): (y: T[]) => T[];
concat(x: string): (y: string) => string;

export function concat(x) {
  return y => (typeof x === 'string' ? `${x}${y}` : [...x, ...y])
}

import { concat, pipe } from 'rambda'

const list1 = [1, 2, 3]
const list2 = [4, 5, 6]

it('R.concat', () => {
  const result = pipe(list1, concat(list2))
  result // $ExpectType number[]
  const resultString = pipe('foo', concat('list2'))
  resultString // $ExpectType string
})

convertToType<T>(x: unknown) : T;

export function convertToType(x) {
  return x
}

import { convertToType, pipe } from 'rambda'

const list = [1, 2, 3]

it('R.convertToType', () => {
  const result = pipe(list, 
		convertToType<string[]>,
		x => {
			x // $ExpectType string[]
			return x 
		}
	)
  result // $ExpectType string[]
})

count<T>(predicate: (x: T) => boolean): (list: T[]) => number;

import { isArray } from './_internals/isArray.js'

export function count(predicate) {
  return list => {
    if (!isArray(list)) {
      return 0
    }

    return list.filter(x => predicate(x)).length
  }
}

import { count } from './count.js'

const predicate = x => x.a !== undefined

test('with empty list', () => {
  expect(count(predicate)([])).toBe(0)
})

test('happy', () => {
  const list = [1, 2, { a: 1 }, 3, { a: 1 }]

  expect(count(predicate)(list)).toBe(2)
})

import { count, pipe } from 'rambda'

const list = [1, 2, 3]
const predicate = (x: number) => x > 1

it('R.count', () => {
  const result = pipe(list, count(predicate))
  result // $ExpectType number
})

countBy<T>(fn: (x: T) => string | number): (list: T[]) => { [index: string]: number };

export function countBy(fn) {
  return list => {
    const willReturn = {}

    list.forEach(item => {
      const key = fn(item)
      if (!willReturn[key]) {
        willReturn[key] = 1
      } else {
        willReturn[key]++
      }
    })

    return willReturn
  }
}

import { countBy } from './countBy.js'

const list = ['a', 'A', 'b', 'B', 'c', 'C']

test('happy', () => {
  const result = countBy(x => x.toLowerCase())(list)
  expect(result).toEqual({
    a: 2,
    b: 2,
    c: 2,
  })
})

import { countBy, pipe } from 'rambda'

const list = ['a', 'A', 'b', 'B', 'c', 'C']

it('R.countBy', () => {
  const result = pipe(
    list,
    countBy(x => x.toLowerCase()),
  )
  result.a // $ExpectType number
  result.foo // $ExpectType number
  result // $ExpectType { [index: string]: number; }
})

createObjectFromKeys<const K extends readonly PropertyKey[], V>(
	fn: (key: K[number]) => V
): (keys: K) => { [P in K[number]]: V };
createObjectFromKeys<const K extends readonly PropertyKey[], V>(
	fn: (key: K[number], index: number) => V
): (keys: K) => { [P in K[number]]: V };

export function createObjectFromKeys(fn) {
	return keys => {
		const result = {}
		keys.forEach((key, index) => {
			result[key] = fn(key, index)
		})

		return result
	}
}

import { createObjectFromKeys } from './createObjectFromKeys.js'

test('happy', () => {
	const result = createObjectFromKeys((key, index) => key.toUpperCase() + index)(['a', 'b'])
	const expected = { a: 'A0', b: 'B1' }

	expect(result).toEqual(expected)
})

defaultTo<T>(defaultValue: T): (input: unknown) => T;

function isFalsy(input) {
  return input === undefined || input === null || Number.isNaN(input) === true
}

export function defaultTo(defaultArgument) {
  return input => isFalsy(input) ? defaultArgument : input
}

import { defaultTo } from './defaultTo.js'

test('with undefined', () => {
  expect(defaultTo('foo')(undefined)).toBe('foo')
})

test('with null', () => {
  expect(defaultTo('foo')(null)).toBe('foo')
})

test('with NaN', () => {
  expect(defaultTo('foo')(Number.NaN)).toBe('foo')
})

test('with empty string', () => {
  expect(defaultTo('foo')('')).toBe('')
})

test('with false', () => {
  expect(defaultTo('foo')(false)).toBeFalsy()
})

test('when inputArgument passes initial check', () => {
  expect(defaultTo('foo')('bar')).toBe('bar')
})

import { defaultTo, pipe } from 'rambda'

describe('R.defaultTo', () => {
  it('happy', () => {
    const result = pipe('bar' as unknown, defaultTo('foo'))

    result // $ExpectType string
  })
})

delay(ms: number): Promise<'RAMBDA_DELAY'>;

export const RAMBDA_DELAY = 'RAMBDA_DELAY'

export function delay(ms) {
  return new Promise(resolve => {
    setTimeout(() => {
      resolve(RAMBDA_DELAY)
    }, ms)
  })
}

descend<T>(fn: (obj: T) => Ord): (a: T, b: T)=> Ordering;

import { createCompareFunction } from './ascend.js'

export function descend(getFunction) {
  return (a, b) => {
    const aValue = getFunction(a)
    const bValue = getFunction(b)

    return createCompareFunction(aValue, bValue, 1, -1)
  }
}

difference<T>(x: T[]): (y: T[]) => T[];

import { filter } from './filter.js'
import { excludes } from './excludes.js'

export function difference(listA) {
	return listB => ([
		...filter(value => excludes(listB)(value))(listA),
		...filter(value => excludes(listA)(value))(listB),
	])
}

import { difference } from './difference.js'

test('difference', () => {
  const list1 = [1, 2, 3, 4]
  const list2 = [3, 4, 5, 6]
  expect(difference(list1)(list2)).toEqual([1, 2, 5, 6])
  expect(difference([])([])).toEqual([])
})

test('difference with objects', () => {
  const list1 = [{ id: 1 }, { id: 2 }, { id: 3 }, { id: 4 }]
  const list2 = [{ id: 3 }, { id: 4 }, { id: 5 }, { id: 6 }]
  expect(difference(list1)(list2)).toEqual([
    { id: 1 },
    { id: 2 },
    { id: 5 },
    { id: 6 },
  ])
})

import { difference } from 'rambda'

describe('R.difference', () => {
  it('happy', () => {
    const list1 = [{ id: 1 }, { id: 2 }, { id: 3 }, { id: 4 }]
    const list2 = [{ id: 3 }, { id: 4 }, { id: 5 }, { id: 6 }]
    const result = difference(list1)(list2)

    result // $ExpectType { id: number; }[]
  })
})

drop<T>(howMany: number): (list: T[]) => T[];

export function drop(howManyToDrop) {
  return list => list.slice(howManyToDrop > 0 ? howManyToDrop : 0)
}

import { drop } from './drop.js'

test('with array', () => {
  expect(drop(2)(['foo', 'bar', 'baz'])).toEqual(['baz'])
  expect(drop(3)(['foo', 'bar', 'baz'])).toEqual([])
  expect(drop(4)(['foo', 'bar', 'baz'])).toEqual([])
})

test('with non-positive count', () => {
  expect(drop(0)([1, 2, 3])).toEqual([1, 2, 3])
  expect(drop(-1)([1, 2, 3])).toEqual([1, 2, 3])
  expect(drop(Number.NEGATIVE_INFINITY)([1, 2, 3])).toEqual([1, 2, 3])
})

import { drop, pipe } from 'rambda'

it('R.drop', () => {
  const result = pipe([1, 2, 3, 4], drop(2))
  result // $ExpectType number[]
})

dropLast<T>(howMany: number): (list: T[]) => T[];

export function dropLast(numberItems) {
  return list => (numberItems > 0 ? list.slice(0, -numberItems) : list.slice())
}

import { dropLast } from './dropLast.js'

test('with array', () => {
  expect(dropLast(2)(['foo', 'bar', 'baz'])).toEqual(['foo'])
  expect(dropLast(3)(['foo', 'bar', 'baz'])).toEqual([])
  expect(dropLast(4)(['foo', 'bar', 'baz'])).toEqual([])
})

test('with non-positive count', () => {
  expect(dropLast(0)([1, 2, 3])).toEqual([1, 2, 3])
  expect(dropLast(-1)([1, 2, 3])).toEqual([1, 2, 3])
  expect(dropLast(Number.NEGATIVE_INFINITY)([1, 2, 3])).toEqual([1, 2, 3])
})

dropLastWhile<T>(predicate: (x: T, index: number) => boolean): (list: T[]) => T[];
dropLastWhile<T>(predicate: (x: T) => boolean): (list: T[]) => T[];

export function dropLastWhile(predicate) {
  return list => {
    if (list.length === 0) {
      return list
    }

    const toReturn = []
    let counter = list.length

    while (counter) {
      const item = list[--counter]
      if (!predicate(item, counter)) {
        toReturn.push(item)
        break
      }
    }

    while (counter) {
      toReturn.push(list[--counter])
    }

    return toReturn.reverse()
  }
}

import { dropLastWhile } from './dropLastWhile.js'

const list = [1, 2, 3, 4, 5]

test('with list', () => {
  const result = dropLastWhile(x => x >= 3)(list)
  expect(result).toEqual([1, 2])
})

test('with empty list', () => {
  expect(dropLastWhile(() => true)([])).toEqual([])
})

dropRepeatsBy<T, U>(fn: (x: T) => U): (list: T[]) => T[];

dropRepeatsWith<T>(predicate: (x: T, y: T) => boolean): (list: T[]) => T[];

dropWhile<T>(predicate: (x: T, index: number) => boolean): (list: T[]) => T[];
dropWhile<T>(predicate: (x: T) => boolean): (list: T[]) => T[];

export function dropWhile(predicate) {
  return iterable => {
    const toReturn = []
    let counter = 0

    while (counter < iterable.length) {
      const item = iterable[counter++]
      if (!predicate(item, counter)) {
        toReturn.push(item)
        break
      }
    }

    while (counter < iterable.length) {
      toReturn.push(iterable[counter++])
    }

    return toReturn
  }
}

import { dropWhile } from './dropWhile.js'

const list = [1, 2, 3, 4]

test('happy', () => {
  const predicate = (x, i) => {
    expect(typeof i).toBe('number')
    return x < 3
  }
  const result = dropWhile(predicate)(list)
  expect(result).toEqual([3, 4])
})

test('always false', () => {
  const predicate = () => 0
  const result = dropWhile(predicate)(list)
  expect(result).toEqual(list)
})

import { dropWhile, pipe } from 'rambda'

const list = [1, 2, 3]

describe('R.dropWhile', () => {
  it('happy', () => {
    const result = pipe(
      list,
      dropWhile(x => x > 1),
    )

    result // $ExpectType number[]
  })
  it('with index', () => {
    const result = pipe(
      list,
      dropWhile((x, i) => {
        i // $ExpectType number
        return x + i > 2
      }),
    )

    result // $ExpectType number[]
  })
})

duplicateBy<T, U>(fn: (x: T) => U): (list: T[]) => T[];

import { _Set } from '../src/_internals/set.js'

export function duplicateBy(fn) {
  return list => {
    const set = new _Set()

    return list.filter(item => !set.checkUniqueness(fn(item)))
  }
}

import { duplicateBy } from './duplicateBy.js'

test('happy', () => {
  expect(duplicateBy(Math.abs)([-2, -1, 0, 1, 2])).toEqual([1,2])
})

test('returns an empty array for an empty array', () => {
  expect(duplicateBy(Math.abs)([])).toEqual([])
})

test('uses R.uniq', () => {
  const list = [{ a: 1 }, { a: 2 }, { a: 1 }]
  const expected = [{ a: 1 }]
  expect(duplicateBy(x => x)(list)).toEqual(expected)
})

eqBy<T>(fn: (x: T) => unknown, a: T): (b: T) => boolean;

import { equalsFn } from './equals.js'

export function eqBy(fn, a) {
  return b => equalsFn(fn(a), fn(b))
}

import { eqBy } from './eqBy.js'

test('deteremines whether two values map to the same value in the codomain', () => {
  expect(eqBy(Math.abs, 5)(5)).toBe(true)
  expect(eqBy(Math.abs, 5)(-5)).toBe(true)
  expect(eqBy(Math.abs, -5)(5)).toBe(true)
  expect(eqBy(Math.abs, -5)(-5)).toBe(true)
  expect(eqBy(Math.abs, 42)(99)).toBe(false)
})

test('has R.equals semantics', () => {
  expect(eqBy(Math.abs, Number.NaN)(Number.NaN)).toBe(true)
  expect(eqBy(Math.abs, [42])([42])).toBe(true)
  expect(eqBy(x => x, { a: 1 })({ a: 1 })).toBe(true)
  expect(eqBy(x => x, { a: 1 })({ a: 2 })).toBe(false)
})

eqProps<T, K extends keyof T>(prop: K, obj1: T): (obj2: T) => boolean;

import { equalsFn } from './equals.js'

export function eqProps(property, objA) {
  return objB => equalsFn( objA[property], objB[property] )
}

import { eqProps } from './eqProps.js'

const obj1 = {
  a: 1,
  b: 2,
}
const obj2 = {
  a: 1,
  b: 3,
}

test('props are equal', () => {
  const result = eqProps('a', obj1)(obj2)
  expect(result).toBeTruthy()
})

test('props are not equal', () => {
  const result = eqProps('b', obj1)(obj2)
  expect(result).toBeFalsy()
})

test('prop does not exist', () => {
  const result = eqProps('c', obj1)(obj2)
  expect(result).toBeTruthy()
})

import { eqProps, pipe } from 'rambda'

const obj1 = { a: { b: 1 }, c: 2 }
const obj2 = { a: { b: 1 }, c: 3 }

it('R.eqProps', () => {
  const result = pipe(obj1, eqProps('a', obj2))

  result // $ExpectType boolean
})

equals<T>(x: T, y: T): boolean;
equals<T>(x: T): (y: T) => boolean;

import { isArray } from './_internals/isArray.js'
import { type } from './type.js'

export function _lastIndexOf(valueToFind, list) {
  if (!isArray(list)) {
    throw new Error(`Cannot read property 'indexOf' of ${list}`)
  }

  const typeOfValue = type(valueToFind)
  if (!['Array', 'NaN', 'Object', 'RegExp'].includes(typeOfValue)) {
    return list.lastIndexOf(valueToFind)
  }

  const { length } = list
  let index = length
  let foundIndex = -1

  while (--index > -1 && foundIndex === -1) {
    if (equalsFn(list[index], valueToFind)) {
      foundIndex = index
    }
  }

  return foundIndex
}

export function _indexOf(valueToFind, list) {
  if (!isArray(list)) {
    throw new Error(`Cannot read property 'indexOf' of ${list}`)
  }

  const typeOfValue = type(valueToFind)
  if (!['Array', 'NaN', 'Object', 'RegExp'].includes(typeOfValue)) {
    return list.indexOf(valueToFind)
  }

  let index = -1
  let foundIndex = -1
  const { length } = list

  while (++index < length && foundIndex === -1) {
    if (equalsFn(list[index], valueToFind)) {
      foundIndex = index
    }
  }

  return foundIndex
}

function _arrayFromIterator(iter) {
  const list = []
  let next
  while (!(next = iter.next()).done) {
    list.push(next.value)
  }

  return list
}

function _compareSets(a, b) {
  if (a.size !== b.size) {
    return false
  }

  const aList = _arrayFromIterator(a.values())
  const bList = _arrayFromIterator(b.values())

  const filtered = aList.filter(aInstance => _indexOf(aInstance, bList) === -1)

  return filtered.length === 0
}

function compareErrors(a, b) {
  if (a.message !== b.message) {
    return false
  }
  if (a.toString !== b.toString) {
    return false
  }

  return a.toString() === b.toString()
}

function parseDate(maybeDate) {
  if (!maybeDate.toDateString) {
    return [false]
  }

  return [true, maybeDate.getTime()]
}

function parseRegex(maybeRegex) {
  if (maybeRegex.constructor !== RegExp) {
    return [false]
  }

  return [true, maybeRegex.toString()]
}

export function equalsFn(a, b) {
  if (Object.is(a, b)) {
    return true
  }

  const aType = type(a)

  if (aType !== type(b)) {
    return false
  }
  if (aType === 'Function') {
    return a.name === undefined ? false : a.name === b.name
  }

  if (['NaN', 'Null', 'Undefined'].includes(aType)) {
    return true
  }

  if (['BigInt', 'Number'].includes(aType)) {
    if (Object.is(-0, a) !== Object.is(-0, b)) {
      return false
    }

    return a.toString() === b.toString()
  }

  if (['Boolean', 'String'].includes(aType)) {
    return a.toString() === b.toString()
  }

  if (aType === 'Array') {
    const aClone = Array.from(a)
    const bClone = Array.from(b)

    if (aClone.toString() !== bClone.toString()) {
      return false
    }

    let loopArrayFlag = true
    aClone.forEach((aCloneInstance, aCloneIndex) => {
      if (loopArrayFlag) {
        if (
          aCloneInstance !== bClone[aCloneIndex] &&
          !equalsFn(aCloneInstance, bClone[aCloneIndex])
        ) {
          loopArrayFlag = false
        }
      }
    })

    return loopArrayFlag
  }

  const aRegex = parseRegex(a)
  const bRegex = parseRegex(b)

  if (aRegex[0]) {
    return bRegex[0] ? aRegex[1] === bRegex[1] : false
  }
  if (bRegex[0]) {
    return false
  }

  const aDate = parseDate(a)
  const bDate = parseDate(b)

  if (aDate[0]) {
    return bDate[0] ? aDate[1] === bDate[1] : false
  }
  if (bDate[0]) {
    return false
  }

  if (a instanceof Error) {
    if (!(b instanceof Error)) {
      return false
    }

    return compareErrors(a, b)
  }

  if (aType === 'Set') {
    return _compareSets(a, b)
  }

  if (aType === 'Object') {
    const aKeys = Object.keys(a)

    if (aKeys.length !== Object.keys(b).length) {
      return false
    }

    let loopObjectFlag = true
    aKeys.forEach(aKeyInstance => {
      if (loopObjectFlag) {
        const aValue = a[aKeyInstance]
        const bValue = b[aKeyInstance]

        if (aValue !== bValue && !equalsFn(aValue, bValue)) {
          loopObjectFlag = false
        }
      }
    })

    return loopObjectFlag
  }

  return false
}
export function equals(a) {
  return b => equalsFn(a, b)
}

import { equalsFn } from './equals.js'

test('compare functions', () => {
  function foo() {}
  function bar() {}
  const baz = () => {}

  const expectTrue = equalsFn(foo, foo)
  const expectFalseFirst = equalsFn(foo, bar)
  const expectFalseSecond = equalsFn(foo, baz)

  expect(expectTrue).toBeTruthy()
  expect(expectFalseFirst).toBeFalsy()
  expect(expectFalseSecond).toBeFalsy()
})

test('with array of objects', () => {
  const list1 = [{ a: 1 }, [{ b: 2 }]]
  const list2 = [{ a: 1 }, [{ b: 2 }]]
  const list3 = [{ a: 1 }, [{ b: 3 }]]

  expect(equalsFn(list1, list2)).toBeTruthy()
  expect(equalsFn(list1, list3)).toBeFalsy()
})

test('with regex', () => {
  expect(equalsFn(/s/, /s/)).toBeTruthy()
  expect(equalsFn(/s/, /d/)).toBeFalsy()
  expect(equalsFn(/a/gi, /a/gi)).toBeTruthy()
  expect(equalsFn(/a/gim, /a/gim)).toBeTruthy()
  expect(equalsFn(/a/gi, /a/i)).toBeFalsy()
})

test('not a number', () => {
  expect(equalsFn([Number.NaN], [Number.NaN])).toBeTruthy()
})

test('new number', () => {
  expect(equalsFn(new Number(0), new Number(0))).toBeTruthy()
  expect(equalsFn(new Number(0), new Number(1))).toBeFalsy()
  expect(equalsFn(new Number(1), new Number(0))).toBeFalsy()
})

test('new string', () => {
  expect(equalsFn(new String(''), new String(''))).toBeTruthy()
  expect(equalsFn(new String(''), new String('x'))).toBeFalsy()
  expect(equalsFn(new String('x'), new String(''))).toBeFalsy()
  expect(equalsFn(new String('foo'), new String('foo'))).toBeTruthy()
  expect(equalsFn(new String('foo'), new String('bar'))).toBeFalsy()
  expect(equalsFn(new String('bar'), new String('foo'))).toBeFalsy()
})

test('new Boolean', () => {
  expect(equalsFn(new Boolean(true), new Boolean(true))).toBeTruthy()
  expect(equalsFn(new Boolean(false), new Boolean(false))).toBeTruthy()
  expect(equalsFn(new Boolean(true), new Boolean(false))).toBeFalsy()
  expect(equalsFn(new Boolean(false), new Boolean(true))).toBeFalsy()
})

test('new Error', () => {
  expect(equalsFn(new Error('XXX'), {})).toBeFalsy()
  expect(equalsFn(new Error('XXX'), new TypeError('XXX'))).toBeFalsy()
  expect(equalsFn(new Error('XXX'), new Error('YYY'))).toBeFalsy()
  expect(equalsFn(new Error('XXX'), new Error('XXX'))).toBeTruthy()
  expect(equalsFn(new Error('XXX'), new TypeError('YYY'))).toBeFalsy()
  expect(equalsFn(new Error('XXX'), new Error('XXX'))).toBeTruthy()
})

test('with dates', () => {
  expect(equalsFn(new Date(0), new Date(0))).toBeTruthy()
  expect(equalsFn(new Date(1), new Date(1))).toBeTruthy()
  expect(equalsFn(new Date(0), new Date(1))).toBeFalsy()
  expect(equalsFn(new Date(1), new Date(0))).toBeFalsy()
  expect(equalsFn(new Date(0), {})).toBeFalsy()
  expect(equalsFn({}, new Date(0))).toBeFalsy()
})

test('ramda spec', () => {
  expect(equalsFn({}, {})).toBeTruthy()

  expect(
    equalsFn(
      {
        a: 1,
        b: 2,
      },
      {
        a: 1,
        b: 2,
      },
    ),
  ).toBeTruthy()

  expect(
    equalsFn(
      {
        a: 2,
        b: 3,
      },
      {
        a: 2,
        b: 3,
      },
    ),
  ).toBeTruthy()

  expect(
    equalsFn(
      {
        a: 2,
        b: 3,
      },
      {
        a: 3,
        b: 3,
      },
    ),
  ).toBeFalsy()

  expect(
    equalsFn(
      {
        a: 2,
        b: 3,
        c: 1,
      },
      {
        a: 2,
        b: 3,
      },
    ),
  ).toBeFalsy()
})

test('works with boolean tuple', () => {
  expect(equalsFn([true, false], [true, false])).toBeTruthy()
  expect(equalsFn([true, false], [true, true])).toBeFalsy()
})

test('works with equal objects within array', () => {
  const objFirst = {
    a: {
      b: 1,
      c: 2,
      d: [1],
    },
  }
  const objSecond = {
    a: {
      b: 1,
      c: 2,
      d: [1],
    },
  }

  const x = [1, 2, objFirst, null, '', []]
  const y = [1, 2, objSecond, null, '', []]
  expect(equalsFn(x, y)).toBeTruthy()
})

test('works with different objects within array', () => {
  const objFirst = { a: { b: 1 } }
  const objSecond = { a: { b: 2 } }

  const x = [1, 2, objFirst, null, '', []]
  const y = [1, 2, objSecond, null, '', []]
  expect(equalsFn(x, y)).toBeFalsy()
})

test('works with undefined as second argument', () => {
  expect(equalsFn(1, undefined)).toBeFalsy()

  expect(equalsFn(undefined, undefined)).toBeTruthy()
})

test('compare sets', () => {
  const toCompareDifferent = new Set([{ a: 1 }, { a: 2 }])
  const toCompareSame = new Set([{ a: 1 }, { a: 2 }, { a: 1 }])
  const testSet = new Set([{ a: 1 }, { a: 2 }, { a: 1 }])
  expect(equalsFn(toCompareSame, testSet)).toBeTruthy()
  expect(equalsFn(toCompareDifferent, testSet)).toBeFalsy()
})

test('compare simple sets', () => {
  const testSet = new Set(['2', '3', '3', '2', '1'])
  expect(equalsFn(new Set(['3', '2', '1']), testSet)).toBeTruthy()
  expect(equalsFn(new Set(['3', '2', '0']), testSet)).toBeFalsy()
})

test('various examples', () => {
  expect(equalsFn([1, 2, 3], [1, 2, 3])).toBeTruthy()
  expect(equalsFn([1, 2, 3], [1, 2])).toBeFalsy()
  expect(equalsFn({}, {})).toBeTruthy()
})

import { equals } from 'rambda'

describe('R.equals', () => {
  it('happy', () => {
    const result = equals(4, 1)
    result // $ExpectType boolean
  })
  it('with object', () => {
    const foo = { a: 1 }
    const bar = { a: 2 }
    const result = equals(foo, bar)
    result // $ExpectType boolean
  })
  it('curried', () => {
    const result = equals(4)(1)

    result // $ExpectType boolean
  })
})

evolve<T>(rules: {
	[K in keyof T]?: (x: T[K]) => T[K]
}): (obj: T) => T;

import { mapObject } from './mapObject.js'
import { type } from './type.js'

export function evolve(rules) {
  return mapObject((x, prop) => type(rules[prop]) === 'Function' ? rules[prop](x): x)
}

import { evolve } from './evolve.js'

test('happy', () => {
  const rules = {
    foo: x => x + 1,
  }
  const input = {
    a: 1,
    foo: 2,
		nested: { bar: { z: 3 } },
  }
  const result = evolve(rules)(input)
  expect(result).toEqual({
    a: 1,
    foo: 3,
		nested: { bar: { z: 3 } },
  })
})

import {  evolve, pipe } from 'rambda'

it('R.evolve', () => {
  const input = {
		baz: 1,
    foo: 2,
    nested: {
      a: 1,
      bar: 3,
    },
  }
  const result = pipe(input, 
		evolve({
			foo: x => x + 1,
		})
	)
  result.foo // $ExpectType number
  result.baz // $ExpectType number
  result.nested.a // $ExpectType number
})

excludes(list: readonly string[] | string): (substringToFind: string) => boolean;
excludes<T>(list: readonly T[]): (target: T) => boolean;

import { includes } from './includes.js'

export function excludes(iterable) {
  return valueToFind => !includes(iterable)(valueToFind)
}

import { excludes } from './excludes.js'

test('excludes with string', () => {
  const str = 'more is less'

  expect(excludes(str)('less')).toBeFalsy()
  expect(excludes(str)('never')).toBeTruthy()
})

test('excludes with array', () => {
  const arr = [1, 2, 3]

  expect(excludes(arr)(2)).toBeFalsy()
  expect(excludes(arr)(4)).toBeTruthy()
})

import { excludes, pipe } from 'rambda'

describe('R.excludes', () => {
  it('happy', () => {
    const list = [{ a: { b: '1' } }, { a: { b: '2' } }, { a: { b: '3' } }]
    const result = pipe({ a: { b: '1' } }, excludes(list))
    result // $ExpectType boolean
  })
  it('with string', () => {
    const result = pipe('foo', excludes('bar'))
    result // $ExpectType boolean
  })
})

exists<T>(predicate: (x: T) => boolean): (list: T[]) => boolean;

import { find } from './find.js'

export function exists(predicate) {
  return list => {
		return find(predicate)(list) !== undefined
  }
}

import { exists } from './exists.js'
import { propEq } from './propEq.js'

const list = [{ a: 1 }, { a: 2 }, { a: 3 }]

test('happy', () => {
  const fn = propEq(2, 'a')
  expect(exists(fn)(list)).toBe(true)
})

test('nothing is found', () => {
  const fn = propEq(4, 'a')
  expect(exists(fn)(list)).toBe(false)
})

import { exists, pipe } from 'rambda'

const list = [1, 2, 3]

describe('R.exists', () => {
  it('happy', () => {
    const predicate = (x: number) => x > 2
    const result = pipe(list, exists(predicate))
    result // $ExpectType boolean
  })
})

filter<T, S extends T>(
  predicate: (value: T) => value is S,
): (list: T[]) => S[];
filter<T>(
	predicate: BooleanConstructor,
): (list: readonly T[]) => ExcludeFalsy<T>[];
filter<T>(
	predicate: BooleanConstructor,
): (list: T[]) => ExcludeFalsy<T>[];
filter<T>(
	predicate: (value: T, index: number) => boolean,
): (list: T[]) => T[];
...
...

export function filter(predicate) {
  return list => {
    if (!list) {
      throw new Error('Incorrect iterable input')
    }
    let index = 0
    const len = list.length
    const willReturn = []

    while (index < len) {
      if (predicate(list[index], index)) {
        willReturn.push(list[index])
      }

      index++
    }

    return willReturn
  }
}

import { filter } from './filter.js'

test('happy', () => {
  const isEven = n => n % 2 === 0

  expect(filter(isEven)([1, 2, 3, 4])).toEqual([2, 4])
})

test('using Boolean', () => {
  expect(filter(Boolean)([null, 0, 1, 2])).toEqual([1,2])
})

import { filter, includes, pipe, reject, sort, split, uniq } from 'rambda'

const list = [1, 2, 3]

describe('R.filter with array', () => {
  it('within pipe', () => {
    const result = pipe(
      list,
      filter(x => {
        x // $ExpectType number
        return x > 1
      }),
    )
    result // $ExpectType number[]
  })

  it('with index', () => {
    const result = pipe(
      list,
      filter((x: number, i: number) => {
        x // $ExpectType number
        i // $ExpectType number
        return x > 1
      }),
    )
    result // $ExpectType number[]
  })

  it('complex example', () => {
    const text = `Dies ist ein einfacher Beispielsatz. Il fait beau aujourd'hui!`
    const language = 'de'
		const SENTENCE_END_CHARS = ['.', '!', '?', '।', '؟']
    const result = pipe(
      text,
      split(''),
      uniq,
      filter(char => {
        if (language === 'de') {
          return /[A-Za-zäßüöÜÖÄ]/g.test(char) === false
        }
        if (language === 'fr') {
          return /[A-Za-zÀÉàâçèéêîïôùû']/g.test(char) === false
        }
        throw new Error(`Language ${language} not supported`)
      }),
      sort((a, b) => (a === b ? 0 : a > b ? 1 : -1)),
      filter(char => char.trim().length > 0),
      reject(includes(SENTENCE_END_CHARS)),
    )

    result // $ExpectType string[]
  })
  it('narrowing type', () => {
    interface Foo {
      a: number
    }
    interface Bar extends Foo {
      b: string
    }
    type T = Foo | Bar
    const testList: T[] = [{ a: 1 }, { a: 2 }, { a: 3 }]
    const filterBar = (x: T): x is Bar => {
      return typeof (x as Bar).b === 'string'
    }
    const result = pipe(testList, filter(filterBar))
    result // $ExpectType Bar[]
  })

  it('narrowing type - readonly', () => {
    interface Foo {
      a: number
    }
    interface Bar extends Foo {
      b: string
    }
    type T = Foo | Bar
    const testList: T[] = [{ a: 1 }, { a: 2 }, { a: 3 }] as const
    const filterBar = (x: T): x is Bar => {
      return typeof (x as Bar).b === 'string'
    }
    const result = pipe(testList, filter(filterBar))
    result // $ExpectType Bar[]
  })

  it('filtering NonNullable - list of objects', () => {
    const testList = [{ a: 1 }, { a: 2 }, false, { a: 3 }]
    const result = pipe(testList, filter(Boolean))
    result // $ExpectType { a: number; }[]
  })

  it('filtering NonNullable - readonly', () => {
    const testList = [1, 2, true, false, null, undefined, 3] as const
    const result = pipe(testList, filter(Boolean))
    result.includes(1)
    // @ts-expect-error
    result.includes(true)
    // @ts-expect-error
    result.includes(false)
    // @ts-expect-error
    result.includes(4)
    // @ts-expect-error
    result.includes(undefined)
    // @ts-expect-error
    result.includes(null)
  })
})

filterAsync<T>(
	predicate: (value: T) => Promise<boolean>,
): (list: T[]) => Promise<T[]>;

export function filterAsync(predicate) {
  return async list => {
    const willReturn = []
    let index = 0
    for (const x of list) {
      if (await predicate(x, index)) {
        willReturn.push(list[index])
      }
      index++
    }

    return willReturn
  }
}

import { filterAsync } from './filterAsync.js'

test('happy', async () => {
  const isEven = async n => n % 2 === 0

  expect(await filterAsync(isEven)([1, 2, 3, 4])).toEqual([2, 4])
})

import { filterAsync, pipeAsync } from 'rambda'

const list = [1, 2, 3]

describe('R.filter with array', () => {
  it('within pipe', async () => {
    const result = await pipeAsync(
      list,
      filterAsync(async x => {
        x // $ExpectType number
        return x > 1
      }),
    )
    result // $ExpectType number[]
  })
})

filterMap<T extends IterableContainer, U>(
	fn: (value: T[number], index: number) => U,
): (data: T) => Mapped<T, ExcludeFalsy<U>>;
filterMap<T extends IterableContainer, U>(
	fn: (value: T[number]) => U,
): (data: T) => Mapped<T, ExcludeFalsy<U>>;

import {mapFn} from './map.js'

export function filterMap(fn) {
  return list => mapFn(fn, list).filter(Boolean)
}

import { filterMap } from './filterMap.js'

const double = x => x > 1 ? x * 2 : null

it('happy', () => {
  expect(filterMap(double)([1, 2, 3])).toEqual([4, 6])
})

import { filterMap, pipe } from 'rambda'

const list = [1, 2, 3]

it('R.filterMap - within pipe', () => {
  const result = pipe(
    list,
    x => x,
    filterMap(x => {
      x // $ExpectType number
      return Math.random() > 0.5 ? String(x) : null
    }),
    filterMap(x => {
      x // $ExpectType string
      return Math.random() > 0.5 ? Number(x) : ''
    }),
  )
  result // $ExpectType number[]
})

filterObject<T extends object>(
  valueMapper: (
    value: EnumerableStringKeyedValueOf<T>,
    key: EnumerableStringKeyOf<T>,
    data: T,
  ) => boolean,
): <U extends T>(data: T) => U;

export function filterObject(predicate) {
  return obj => {
    const willReturn = {}

    for (const prop in obj) {
      if (predicate(obj[prop], prop, obj)) {
        willReturn[prop] = obj[prop]
      }
    }

    return willReturn
  }
}

import { pipe } from './pipe.js'
import { filterObject } from './filterObject.js'

test('happy', () => {
	let testInput = { a: 1, b: 2, c: 3 }
  const result = pipe(
		testInput,
		filterObject((x, prop, obj) => {
			expect(prop).toBeOneOf(['a', 'b', 'c'])
			expect(obj).toBe(testInput)
			return x > 1
		})
	)
	expect(result).toEqual({ b: 2, c: 3 })
})

import { filterObject, pipe } from 'rambda'

describe('R.filterObject', () => {
  it('require explicit type', () => {
    const result = pipe(
      { a: 1, b: 2 },
      filterObject<{ b: number }>(a => {
        a // $ExpectType number
        return a > 1
      }),
    )
    result.b // $ExpectType number
  })
})

find<T>(predicate: (x: T) => boolean): (list: T[]) => T | undefined;

export function find(predicate) {
  return list => {
    let index = 0
    const len = list.length

    while (index < len) {
      const x = list[index]
      if (predicate(x)) {
        return x
      }

      index++
    }
  }
}

import { find } from './find.js'
import { propEq } from './propEq.js'

const list = [{ a: 1 }, { a: 2 }, { a: 3 }]

test('happy', () => {
  const fn = propEq(2, 'a')
  expect(find(fn)(list)).toEqual({ a: 2 })
})

test('nothing is found', () => {
  const fn = propEq(4, 'a')
  expect(find(fn)(list)).toBeUndefined()
})

test('with empty list', () => {
  expect(find(() => true)([])).toBeUndefined()
})

import { find, pipe } from 'rambda'

const list = [1, 2, 3]

describe('R.find', () => {
  it('happy', () => {
    const predicate = (x: number) => x > 2
    const result = pipe(list, find(predicate))
    result // $ExpectType number | undefined
  })
})

findIndex<T>(predicate: (x: T) => boolean): (list: T[]) => number;

export function findIndex(predicate) {
  return list => {
    const len = list.length
    let index = -1

    while (++index < len) {
      if (predicate(list[index])) {
        return index
      }
    }

    return -1
  }
}

import { findIndex } from './findIndex.js'
import { propEq } from './propEq.js'

const list = [{ a: 1 }, { a: 2 }, { a: 3 }]

test('happy', () => {
  expect(findIndex(propEq(2, 'a'))(list)).toBe(1)
  expect(findIndex(propEq(1, 'a'))(list)).toBe(0)
  expect(findIndex(propEq(4, 'a'))(list)).toBe(-1)
})

import { findIndex, pipe } from 'rambda'

const list = [1, 2, 3]

it('R.findIndex', () => {
  const result = pipe(
    list,
    findIndex(x => x > 2),
  )
  result // $ExpectType number
})

findLast<T>(fn: (x: T) => boolean): (list: T[]) => T | undefined;

export function findLast(predicate) {
  return list => {
    let index = list.length

    while (--index >= 0) {
      if (predicate(list[index])) {
        return list[index]
      }
    }

    return undefined
  }
}

findLastIndex<T>(predicate: (x: T) => boolean): (list: T[]) => number;

export function findLastIndex(fn) {
  return list => {
    let index = list.length

    while (--index >= 0) {
      if (fn(list[index])) {
        return index
      }
    }

    return -1
  }
}

import { findLastIndex } from './findLastIndex.js'

test('happy', () => {
  const result = findLastIndex(x => x > 1)([1, 1, 1, 2, 3, 4, 1])
  expect(result).toBe(5)
  expect(findLastIndex(x => x === 0)([0, 1, 1, 2, 3, 4, 1])).toBe(0)
})

import { findLastIndex, pipe } from 'rambda'

const list = [1, 2, 3]

describe('R.findLastIndex', () => {
  it('happy', () => {
    const predicate = (x: number) => x > 2
    const result = pipe(list, findLastIndex(predicate))
    result // $ExpectType number
  })
})

findNth<T>(predicate: (x: T) => boolean, nth: number): (list: T[]) => T | undefined;

export function findNth(predicate, nth) {
  return list => {
    let index = 0
    const len = list.length

    while (index < len) {
      const x = list[index]
      if (predicate(x)) {
				if (nth === 0) return x
				nth--
      }

      index++
    }
  }
}

import { findNth } from './findNth.js'

const list = [{ a: 1 }, { a: 2 }, { a: 3 }, { a: 4 }]

test('happy', () => {
  const fn = x => x.a > 1
  expect(findNth(fn,1)(list)).toEqual({ a: 3 })
})

test('nothing is found', () => {
	const fn = x => x.a > 4
	expect(findNth(fn,1)(list)).toBeUndefined()
})

flatMap<T, U extends unknown>(transformFn: (x: T extends any[] ? T[number]: never) => U): (listOfLists: T[]) => U[];

export function flatMap(fn) {
  return list => [].concat(...list.map(fn))
}

import { flatMap } from './flatMap.js'

const duplicate = n => [n, n]

test('happy', () => {
  const fn = x => [x * 2]
  const list = [1, 2, 3]

  const result = flatMap(fn)(list)

  expect(result).toEqual([2, 4, 6])
})

test('maps then flattens one level', () => {
  expect(flatMap(duplicate)([1, 2, 3])).toEqual([1, 1, 2, 2, 3, 3])
})

test('maps then flattens one level', () => {
  expect(flatMap(duplicate)([1, 2, 3])).toEqual([1, 1, 2, 2, 3, 3])
})

test('flattens only one level', () => {
  const nest = n => [[n]]
  expect(flatMap(nest)([1, 2, 3])).toEqual([[1], [2], [3]])
})

test('can compose', () => {
  function dec(x) {
    return [x - 1]
  }
  function times2(x) {
    return [x * 2]
  }

  const mdouble = flatMap(times2)
  const mdec = flatMap(dec)
  expect(mdec(mdouble([10, 20, 30]))).toEqual([19, 39, 59])
})

import { flatMap, pipe } from 'rambda'

describe('R.flatMap', () => {
  it('happy', () => {
    const listOfLists: string[][] = [
      ['f', 'bar'],
      ['baz', 'b'],
    ]
    const result = pipe(
      listOfLists,
      x => x,
      flatMap(x => {
        x // $ExpectType string
        return Number(x) + 1
      }),
    )
    result // $ExpectType number[]
  })
})

flatten<T>(list: any[]): T[];

import { isArray } from './_internals/isArray.js'

export function flatten(list, input) {
  const willReturn = input === undefined ? [] : input

  for (let i = 0; i < list.length; i++) {
    if (isArray(list[i])) {
      flatten(list[i], willReturn)
    } else {
      willReturn.push(list[i])
    }
  }

  return willReturn
}

import { flatten } from './flatten.js'

test('happy', () => {
  expect(flatten([1, 2, 3, [[[[[4]]]]]])).toEqual([1, 2, 3, 4])

  expect(flatten([1, [2, [[3]]], [4]])).toEqual([1, 2, 3, 4])

  expect(flatten([1, [2, [[[3]]]], [4]])).toEqual([1, 2, 3, 4])

  expect(flatten([1, 2, [3, 4], 5, [6, [7, 8, [9, [10, 11], 12]]]])).toEqual([
    1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12,
  ])
})

test('readme example', () => {
  const result = flatten([1, 2, [3, 30, [300]], [4]])
  expect(result).toEqual([1, 2, 3, 30, 300, 4])
})

import { flatten, pipe } from 'rambda'

describe('flatten', () => {
  it('happy', () => {
    const result = pipe([1, 2, [3, [4]]], flatten<number>)
    result // $ExpectType number[]
  })
})

flattenObject<T extends object>(obj: T): FlattenObject<T>;

import { type } from './type.js'

export function flattenObjectHelper(obj, accumulator = []){
  const willReturn = {}
  Object.keys(obj).forEach(key => {
    const typeIs = type(obj[ key ])
    if (typeIs === 'Object'){
      const [ flatResultValue, flatResultPath ] = flattenObjectHelper(obj[ key ],
        [ ...accumulator, key ])
      willReturn[ flatResultPath.join('.') ] = flatResultValue

      return
    } else if (accumulator.length > 0){
      const finalKey = [ ...accumulator, key ].join('.')
      willReturn[ finalKey ] = obj[ key ]

      return
    }
    willReturn[ key ] = obj[ key ]
  })
  if (accumulator.length > 0) return [ willReturn, accumulator ]

  return willReturn
}

export function transformFlatObject(obj){
  const willReturn = {}

  const transformFlatObjectFn = objLocal => {
    const willReturnLocal = {}
    Object.keys(objLocal).forEach(key => {
      const typeIs = type(objLocal[ key ])
      if (typeIs === 'Object'){
        transformFlatObjectFn(objLocal[ key ])

        return
      }
      willReturnLocal[ key ] = objLocal[ key ]
      willReturn[ key ] = objLocal[ key ]
    })

    return willReturnLocal
  }

  Object.keys(obj).forEach(key => {
    const typeIs = type(obj[ key ])
    if (typeIs === 'Object'){
      transformFlatObjectFn(obj[ key ], key)

      return
    }
    willReturn[ key ] = obj[ key ]
  })

  return willReturn
}

export function flattenObject(obj){
  const willReturn = {}

  Object.keys(obj).forEach(key => {
    const typeIs = type(obj[ key ])
    if (typeIs === 'Object'){
      const flatObject = flattenObjectHelper(obj[ key ])
      const transformed = transformFlatObject(flatObject)

      Object.keys(transformed).forEach(keyTransformed => {
        willReturn[ `${ key }.${ keyTransformed }` ] = transformed[ keyTransformed ]
      })
    } else {
      willReturn[ key ] = obj[ key ]
    }
  })

  return willReturn
}

import {
  flattenObject,
  flattenObjectHelper,
  transformFlatObject,
} from './flattenObject.js'

test('happy', () => {
  const obj = {
    c : 3,
    d : {
      'd.e' : [ 5, 6, 7 ],
      'd.z' : 4,
      'd.f' : { 'd.f.h' : 6 },
    },
  }
  const result = transformFlatObject(obj)
  expect(result).toEqual({
    'c'     : 3,
    'd.e'   : [ 5, 6, 7 ],
    'd.z'   : 4,
    'd.f.h' : 6,
  })
})

test('happy', () => {
  const result = flattenObject({
    a : 1,
    b : {
      c : 3,
      d : {
        e : 5,
        z : 4,
        f : {
          h : 6,
          i : 7,
          j : {
            k : 8,
            l : 9,
          },
        },
      },
    },
  })
    const expected = {
      'a'         : 1,
      'b.c'       : 3,
      'b.d.e'     : 5,
      'b.d.z'     : 4,
      'b.d.f.h'   : 6,
      'b.d.f.i'   : 7,
      'b.d.f.j.k' : 8,
      'b.d.f.j.l' : 9,
    }
    expect(result).toEqual(expected)
})

test('flattenObjectHelper', () => {
  const result = flattenObjectHelper({
    a : 1,
    b : {
      c : 3,
      d : {
        e : 5,
        z : 4,
        f : { h : 6 },
      },
    },
  })
  const expected = {
    a : 1,
    b : {
      'b.c' : 3,
      'b.d' : {
        'b.d.e' : 5,
        'b.d.z' : 4,
        'b.d.f' : { 'b.d.f.h' : 6 },
      },
    },
  }
  expect(result).toEqual(expected)
})

import { flattenObject, pipe } from 'rambda'

it('R.flattenObject', () => {
  const result = pipe({ a: { b: 1, c: 2 } }, flattenObject)
  result['a.b'] // $ExpectType number
  result['a.c'] // $ExpectType number
  // @ts-expect-error
  result['a.foo']
})

groupBy<T, K extends string = string>(fn: (x: T) => K): (list: T[]) => Partial<Record<K, T[]>>;

export function groupByFallback(groupFn, list) {
    const result = {}
    for (let i = 0; i < list.length; i++) {
      const item = list[i]
      const key = groupFn(item)

      if (!result[key]) {
        result[key] = []
      }

      result[key].push(item)
    }

    return result
}

export function groupBy(groupFn) {
  return iterable => Object.groupBy ? Object.groupBy(iterable,groupFn) : groupByFallback(groupFn, iterable)
}

import { groupBy } from './groupBy.js'

test('with list', () => {
  const inventory = [
		{ name: "asparagus", type: "vegetables", quantity: 9 },
		{ name: "bananas", type: "fruit", quantity: 5 },
		{ name: "goat", type: "meat", quantity: 23 },
		{ name: "cherries", type: "fruit", quantity: 12 },
		{ name: "fish", type: "meat", quantity: 22 },
	];
  const result = groupBy(
		({ quantity }) =>
			quantity < 6 ? "restock" : "sufficient"
	
	)(inventory)
	expect(result.restock).toEqual([
		{ name: "bananas", type: "fruit", quantity: 5 },
	]);
	expect(result.sufficient[0]).toEqual(
		{ name: "asparagus", type: "vegetables", quantity: 9 }
	);
})

import { groupBy, pipe } from 'rambda'

describe('R.groupBy', () => {
  it('happy', () => {
    const groupByFn = (x: string) => String(x.length)
    const list = ['foo', 'bar']

    const result = pipe(list, groupBy(groupByFn))
    result // $ExpectType Partial<Record<string, string[]>>
  })
})

head<T>(listOrString: T): T extends string ? string :
	T extends [] ? undefined:
		T extends readonly [infer F, ...infer R] ? F :
			T extends readonly [infer F] ? F :
				T extends [infer F] ? F :
					T extends [infer F, ...infer R] ? F :
						T extends unknown[] ? T[number] :
							undefined;

export function head(listOrString) {
  if (typeof listOrString === 'string') {
    return listOrString[0] || ''
  }

  return listOrString[0]
}

import { head } from './head.js'

test('head', () => {
  expect(head(['fi', 'fo', 'fum'])).toBe('fi')
  expect(head([])).toBeUndefined()
  expect(head('foo')).toBe('f')
  expect(head('')).toBe('')
})

import { head, last } from 'rambda'

export const mixedList = [1, 'foo', 3, 'bar']
export const mixedListConst = [1, 'foo', 3, 'bar'] as const
export const numberList = [1, 2, 3]
export const numberListConst = [1, 2, 3] as const
export const emptyList = []
export const emptyString = ''
export const string = 'foo'

describe('R.head', () => {
  it('string', () => {
    head(string) // $ExpectType string
    last(string) // $ExpectType string
  })
  it('empty string', () => {
    head(emptyString) // $ExpectType string
    last(emptyString) // $ExpectType string
  })
  it('array', () => {
    head(numberList) // $ExpectType number
    head(numberListConst) // $ExpectType 1

    last(numberList) // $ExpectType number
    last(numberListConst) // $ExpectType 3
  })
  it('empty array', () => {
    const list = [] as const
    head(emptyList) // $ExpectType never
    head(list) // $ExpectType undefined
    last(emptyList) // $ExpectType never
    last(list) // $ExpectType undefined
  })

  it('mixed', () => {
    head(mixedList) // $ExpectType string | number
    head(mixedListConst) // $ExpectType 1
    last(mixedList) // $ExpectType string | number
    last(mixedListConst) // $ExpectType "bar"
  })
})

includes<T>(list: readonly T[]): (target: T) => boolean;
includes(list: readonly string[] | string): (substringToFind: string) => boolean;

import { isArray } from './_internals/isArray.js'
import { _indexOf } from './equals.js'

export function includes(iterable) {
  return valueToFind => {
    if (typeof iterable === 'string') {
      return iterable.includes(valueToFind)
    }
    if (!iterable) {
      throw new TypeError(`Cannot read property \'indexOf\' of ${iterable}`)
    }
    if (!isArray(iterable)) {
      return false
    }

    return _indexOf(valueToFind, iterable) > -1
  }
}

import { includes } from './includes.js'

test('with string as iterable', () => {
  const str = 'foo bar'

  expect(includes(str)('foo')).toBeTruthy()
  expect(includes(str)('never')).toBeFalsy()
})

test('with array as iterable', () => {
  const arr = [1, 2, 3]

  expect(includes(arr)(2)).toBeTruthy()
  expect(includes(arr)(4)).toBeFalsy()
})

test('with list of objects as iterable', () => {
  const arr = [{ a: 1 }, { b: 2 }, { c: 3 }]

  expect(includes(arr)({ c: 3 })).toBeTruthy()
})

test('with NaN', () => {
  const result = includes([Number.NaN])(Number.NaN)
  expect(result).toBeTruthy()
})

test('with wrong input that does not throw', () => {
  const result = includes([1])(/foo/g)
  expect(result).toBeFalsy()
})

import { pipe , includes} from 'rambda'

describe('R.includes', () => {
  it('happy', () => {
    const list = [{ a: { b: '1' } }, { a: { b: '2' } }, { a: { b: '3' } }]
    const result = pipe({ a: { b: '1' } }, includes(list))
    result // $ExpectType boolean
  })
  it('with string', () => {
    const result = pipe('oo', includes('foo'))
    result // $ExpectType boolean
  })
  it('with array of strings', () => {
		const result = pipe('1', includes(['1','2','3']))
    result // $ExpectType boolean
  })
})

indexBy<T, K extends keyof T>(
  property: K
): (list: readonly T[]) => Record<string, T>;
indexBy<T, K extends keyof T>(
  property: K
): (list: T[]) => Record<string, T>;

export function indexBy(property){
	return list => {
		const toReturn = {}
		for (let i = 0; i < list.length; i++){
			const item = list[ i ]
			const key = item[property]
			if(key !== undefined){
				toReturn[ key ] = item
			}
		}
	
		return toReturn
	}
}

import { indexBy } from './indexBy.js'

test('happy', () => {
	const list = [{id: 'xyz', title: 'A'}, {id: 'abc', title: 'B'}]

	expect(
		indexBy('id')(list)
	).toEqual(
		{abc: {id: 'abc', title: 'B'}, xyz: {id: 'xyz', title: 'A'}}
	)
})

import { pipe, indexBy } from 'rambda'

it('R.indexBy', () => {
	const list = [{id: 'xyz', title: 'A'}, {id: 'abc', title: 'B'}]
	const result = pipe(
		list,
		indexBy('id')
	)
	result.abc // $ExpectType { id: string; title: string; }
	result.foo // $ExpectType { id: string; title: string; }
})

indexOf<T>(valueToFind: T): (list: T[]) => number;

import { _indexOf } from './equals.js'

export function indexOf(valueToFind) {
  return list => _indexOf(valueToFind, list)
}

import { indexOf } from './indexOf.js'

test('with NaN', () => {
  expect(indexOf(Number.NaN)([Number.NaN])).toBe(0)
})

test('will throw with bad input', () => {
  expect(() => indexOf([])(true)).toThrow()
})

test('with numbers', () => {
  expect(indexOf(3)([1, 2, 3, 4])).toBe(2)
  expect(indexOf(10)([1, 2, 3, 4])).toBe(-1)
})

test('list of objects use R.equals', () => {
  const listOfObjects = [{ a: 1 }, { b: 2 }, { c: 3 }]
  expect(indexOf({ c: 4 })(listOfObjects)).toBe(-1)
  expect(indexOf({ c: 3 })(listOfObjects)).toBe(2)
})

test('list of arrays use R.equals', () => {
  const listOfLists = [[1], [2, 3], [2, 3, 4], [2, 3], [1], []]
  expect(indexOf([])(listOfLists)).toBe(5)
  expect(indexOf([1])(listOfLists)).toBe(0)
  expect(indexOf([2, 3, 4])(listOfLists)).toBe(2)
  expect(indexOf([2, 3, 5])(listOfLists)).toBe(-1)
})

import { indexOf } from 'rambda'

describe('R.indexOf', () => {
  it('happy', () => {
    const list = [{ a: 1 }, { a: 2 }]
    const result = indexOf({ a: 1 })(list)
    result // $ExpectType number
  })
})

init<T extends unknown>(input: T): T extends unknown[] ? 
	T['length'] extends 0 ? [] : T['length'] extends 1 ? [] : 
	T extends [...infer U, any] ? U : T : T extends string ? string : never;

import { baseSlice } from './_internals/baseSlice.js'

export function init(input) {
  if (typeof input === 'string') {
    return input.slice(0, -1)
  }

  return input.length ? baseSlice(input, 0, -1) : []
}

import { init } from './init.js'

test('with array', () => {
  expect(init([1, 2, 3])).toEqual([1, 2])
  expect(init([1, 2])).toEqual([1])
  expect(init([1])).toEqual([])
  expect(init([])).toEqual([])
  expect(init([])).toEqual([])
  expect(init([1])).toEqual([])
})

test('with string', () => {
  expect(init('foo')).toBe('fo')
  expect(init('f')).toBe('')
  expect(init('')).toBe('')
})

import { map, pipe, init } from 'rambda'

describe('R.init', () => {
  it('with string', () => {
    const result = init('foo')

    result // $ExpectType string
  })
  it('with list - using const on short array', () => {
    const result = pipe(
      [1] as const,
      map(x => x * 2),
      init,
    )
    result // $ExpectType []
  })
  it('with list - using const on empty array', () => {
    const result = pipe(
      [] as const,
      map(x => x * 2),
      init,
    )
    result // $ExpectType []
  })
  it('with list - using const', () => {
    const result = pipe(
      [1, 2, 3] as const,
      map(x => x * 2),
      init,
    )
    result // $ExpectType [number, number]
  })
  it('with list - mixed types', () => {
    const result = init(['foo', 'bar', 1, 2, 3])

    result // $ExpectType (string | number)[]
  })
})

interpolate(inputWithTags: string): (templateArguments: object) => string;

const getOccurrences = input => input.match(/{{\s*.+?\s*}}/g)
const getOccurrenceProp = occurrence => occurrence.replace(/{{\s*|\s*}}/g, '')

const replace = ({ inputHolder, prop, replacer }) => {
  const regexBase = `{{${prop}}}`
  const regex = new RegExp(regexBase, 'g')
  return inputHolder.replace(regex, replacer)
}

export function interpolate(input) {
  return templateInput => {
    const occurrences = getOccurrences(input)
    if (occurrences === null) {
      return input
    }
    let inputHolder = input

    for (const occurrence of occurrences) {
      const prop = getOccurrenceProp(occurrence)
      inputHolder = replace({
        inputHolder,
        prop,
        replacer: templateInput[prop],
      })
    }

    return inputHolder
  }
}

import { interpolate } from './interpolate.js'
import { pipe } from './pipe.js'

test('happy', () => {
  const result = pipe(
		{ name: 'John', age: 30 },
		interpolate('My name is {{name}} and I am {{age}} years old')
	)
	expect(result).toBe('My name is John and I am 30 years old')
})

import { interpolate } from 'rambda'

const templateInput = 'foo {{x}} baz'
const templateArguments = { x: 'led zeppelin' }

it('R.interpolate', () => {
	const result = interpolate(templateInput)(templateArguments)

	result // $ExpectType string
})

intersection<T>(listA: T[]): (listB: T[]) => T[];

import { filter } from './filter.js'
import { includes } from './includes.js'

export function intersection(listA) {
  return listB => filter(includes(listA))(listB)
}

import { intersection } from './intersection.js'

test('intersection', () => {
  const list1 = [1, 2, 3, 4]
  const list2 = [3, 4, 5, 6]
  expect(intersection(list1)(list2)).toEqual([3, 4])
  expect(intersection([])([])).toEqual([])
})

test('intersection with objects', () => {
  const list1 = [{ id: 1 }, { id: 2 }, { id: 3 }, { id: 4 }]
  const list2 = [{ id: 3 }, { id: 4 }, { id: 5 }, { id: 6 }]
  expect(intersection(list1)(list2)).toEqual([{ id: 3 }, { id: 4 }])
})

test('order is the same as in Ramda', () => {
  const list = ['a', 'b', 'c', 'd']

  expect(intersection(list)(['b', 'c'])).toEqual(['b', 'c'])
  expect(intersection(list)(['c', 'b'])).toEqual(['c', 'b'])
})

import { intersection } from 'rambda'

const list1 = [1, 2, 3]
const list2 = [1, 3, 5]

describe('R.intersection', () => {
  it('happy', () => {
    const result = intersection(list1)(list2)
    result // $ExpectType number[]
  })
})

intersectionWith<T1, T2>(
  pred: (a: T1, b: T2) => boolean,
  list1: T1[],
): (list2: T2[]) => T1[];

function _includesWith(pred, x, list) {
  let idx = 0
  const len = list.length

  while (idx < len) {
    if (pred(x, list[idx])) {
      return true
    }

    idx += 1
  }

  return false
}
function _filter(fn, list) {
  let idx = 0
  const len = list.length
  const result = []

  while (idx < len) {
    if (fn(list[idx])) {
      result[result.length] = list[idx]
    }

    idx += 1
  }

  return result
}

export function intersectionWith(pred, xs) {
  return ys => _filter(x => _includesWith(pred, x, ys), xs)
}

import { intersectionWith } from './intersectionWith.js'

const a = {
  id: 1,
  name: 'a',
}
const b = {
  id: 2,
  name: 'b',
}
const c = {
  id: 3,
  name: 'c',
}
const f = (a, b) => intersectionWith((r, id) => r.id === id, a)(b)

test('only returns elements from the first list', () => {
  expect(f([a, b, c], [])).toEqual([])
  expect(f([a, b, c], [1])).toEqual([a])
  expect(f([a, b, c], [1, 2])).toEqual([a, b])
  expect(f([a, b, c], [1, 2, 3])).toEqual([a, b, c])
  expect(f([a, b, c], [1, 2, 3, 4])).toEqual([a, b, c])
})

test('does not remove duplicates', () => {
  expect(f([a, a, a], [1, 2, 3])).toEqual([a, a, a])
  expect(f([a, b, c], [1, 1, 1])).toEqual([a])
})

test('readme example', () => {
  const list1 = [1, 2, 3, 4, 5]
  const list2 = [4, 5, 6]
  const predicate = (x, y) => x >= y
  const result = intersectionWith(predicate, list1)(list2)
  expect(result).toEqual([4, 5])
})

import { intersectionWith, pipe } from 'rambda'

const list1 = [1, 2, 3]
const list2 = [1, 3, 5]

describe('R.intersectionWith', () => {
  it('happy', () => {
    const result = pipe(
      list1,
      intersectionWith((x, y) => x === y, list2),
    )
    result // $ExpectType number[]
  })
})

intersperse<T>(separator: T): (list: T[]) => T[];

export function intersperse(separator) {
  return list => {
    let index = -1
    const len = list.length
    const willReturn = []

    while (++index < len) {
      if (index === len - 1) {
        willReturn.push(list[index])
      } else {
        willReturn.push(list[index], separator)
      }
    }

    return willReturn
  }
}

import { intersperse } from './intersperse.js'

test('intersperse', () => {
  const list = [{ id: 1 }, { id: 2 }, { id: 10 }, { id: 'a' }]
  expect(intersperse('!')(list)).toEqual([
    { id: 1 },
    '!',
    { id: 2 },
    '!',
    { id: 10 },
    '!',
    { id: 'a' },
  ])

  expect(intersperse('!')([])).toEqual([])
})

import { intersperse } from 'rambda'

describe('R.intersperse', () => {
  it('curried', () => {
    const result = intersperse('|')(['foo', 'bar'])
    result // $ExpectType string[]
  })
})

join<T>(glue: string): (list: T[]) => string;

export function join(glue) {
  return list => list.join(glue)
}

import { join, pipe } from 'rambda'

it('R.join', () => {
  const result = pipe([1, 2, 3], join('|'))
  result // $ExpectType string
})

last<T>(listOrString: T): T extends string ? string :
  T extends [] ? undefined :
    T extends readonly [...infer R, infer L] ? L :
      T extends readonly [infer L] ? L :
        T extends [infer L] ? L :
          T extends [...infer R, infer L] ? L :
            T extends unknown[] ? T[number] :
              undefined;

export function last(listOrString) {
  if (typeof listOrString === 'string') {
    return listOrString[listOrString.length - 1] || ''
  }

  return listOrString[listOrString.length - 1]
}

import { last } from './last.js'

test('with list', () => {
  expect(last([1, 2, 3])).toBe(3)
  expect(last([])).toBeUndefined()
})

test('with string', () => {
  expect(last('abc')).toBe('c')
  expect(last('')).toBe('')
})

lastIndexOf<T>(target: T): (list: T[]) => number;

import { _lastIndexOf } from './equals.js'

export function lastIndexOf(valueToFind) {
  return list => _lastIndexOf(valueToFind, list)
}

import { lastIndexOf } from './lastIndexOf.js'

test('with NaN', () => {
  expect(lastIndexOf(Number.NaN)([Number.NaN])).toBe(0)
})

test('will throw with bad input', () => {
  expect(() => indexOf([])(true)).toThrowError('indexOf is not defined')
})

test('without list of objects - no R.equals', () => {
  expect(lastIndexOf(3)([1, 2, 3, 4])).toBe(2)
  expect(lastIndexOf(10)([1, 2, 3, 4])).toBe(-1)
})

test('list of objects uses R.equals', () => {
  const listOfObjects = [{ a: 1 }, { b: 2 }, { c: 3 }]
  expect(lastIndexOf({ c: 4 })(listOfObjects)).toBe(-1)
  expect(lastIndexOf({ c: 3 })(listOfObjects)).toBe(2)
})

test('list of arrays uses R.equals', () => {
  const listOfLists = [[1], [2, 3], [2, 3, 4], [2, 3], [1], []]
  expect(lastIndexOf([])(listOfLists)).toBe(5)
  expect(lastIndexOf([1])(listOfLists)).toBe(4)
  expect(lastIndexOf([2, 3, 4])(listOfLists)).toBe(2)
  expect(lastIndexOf([2, 3, 5])(listOfLists)).toBe(-1)
})

import { lastIndexOf, pipe } from 'rambda'

describe('R.lastIndexOf', () => {
  const result = pipe([{ a: 1 }, { a: 2 }, { a: 3 }], lastIndexOf({ a: 2 }))
  result // $ExpectType number
})

map<T extends IterableContainer, U>(
	fn: (value: T[number], index: number) => U,
): (data: T) => Mapped<T, U>;
map<T extends IterableContainer, U>(
	fn: (value: T[number]) => U,
): (data: T) => Mapped<T, U>;

export function mapFn(
	fn, list
){
	let index = 0
	const willReturn = Array(list.length)
	while (index < list.length) {
		willReturn[index] = fn(list[index], index)
		index++
	}
	return willReturn
}

export function map(fn) {
  return list => mapFn(fn, list)
}

import { map } from './map.js'

const double = x => x * 2

it('happy', () => {
  expect(map(double)([1, 2, 3])).toEqual([2, 4, 6])
})

import { map, pipe } from 'rambda'

const list = [1, 2, 3]

it('R.map', () => {
  const result = pipe(
    list,
    x => x,
    map(x => {
      x // $ExpectType number
      return String(x)
    }),
  )
  result // $ExpectType string[]
})

it('R.map - index in functor', () => {
  const result = pipe(
    list,
    x => x,
    map((x, i) => {
      x // $ExpectType number
      i // $ExpectType number
      return String(x)
    }),
  )
  result // $ExpectType string[]
})

it('R.map - without pipe', () => {
  map(x => {
    x // $ExpectType unknown
  })([1, 2, 3])
})

it('R.map - without pipe but explicitly typed', () => {
  const result = map<number[], string>(x => {
    x // $ExpectType number
    return String(x)
  })([1, 2, 3])
  result // $ExpectType string[]
})

mapAsync<T extends IterableContainer, U>(
  fn: (value: T[number], index: number) => Promise<U>,
): (data: T) => Promise<Mapped<T, U>>;
mapAsync<T extends IterableContainer, U>(
  fn: (value: T[number]) => Promise<U>,
): (data: T) => Promise<Mapped<T, U>>;

export function mapAsync(fn) {
  return async list => {
    const willReturn = []
    let i = 0
    for (const x of list) {
      willReturn.push(await fn(x, i++))
    }

    return willReturn
  }
}

import { delay } from './delay.js'
import { map } from './map.js'
import { mapAsync } from './mapAsync.js'
import { pipeAsync } from './pipeAsync.js'

const rejectDelay = a =>
  new Promise((_, reject) => {
    setTimeout(() => {
      reject(a + 20)
    }, 100)
  })

test('happy', async () => {
  const indexes = []
  const fn = async (x, prop) => {
    await delay(100)
    indexes.push(prop)
    return x + 1
  }
  const result = await mapAsync(fn)([1, 2, 3])
  expect(result).toEqual([2, 3, 4])
  expect(indexes).toEqual([0, 1, 2])
})

test('with R.pipeAsync', async () => {
	const fn = async x => x + 1
  const result = await pipeAsync(
    [1, 2, 3],
    map(x => x + 1),
    mapAsync(async x => {
      delay(x)

      return x
    }),
		mapAsync(fn),
    map(x => x * 10),
  )
  expect(result).toEqual([30, 40, 50])
})

test('error', async () => {
  try {
    await mapAsync(rejectDelay)([1, 2, 3])
  } catch (err) {
    expect(err).toBe(21)
  }
})

import { mapAsync, pipeAsync, map } from 'rambda'

const list = ['a', 'bc', 'def']
const delay = (ms: number) => new Promise(resolve => setTimeout(resolve, ms))

it('R.mapAsync', async () => {
  const result = await pipeAsync(
    list,
    mapAsync(async x => {
      await delay(100)
      x // $ExpectType string
      return x.length % 2 ? x.length + 1 : x.length + 10
    }),
    x => x,
		map(x => x +1),
    mapAsync(async x => {
      await delay(100)
      return x + 1
    }),
  )
  result // $ExpectType number[]
})

mapChain<T extends IterableContainer, U, V>(
	fn1: (value: T[number], index: number) => U,
	fn2: (value: U, index: number) => V,
): (data: T) => Mapped<T, V>;
mapChain<T extends IterableContainer, U, V>(
	fn1: (value: T[number], index: number) => U,
	fn2: (value: U) => V,
): (data: T) => Mapped<T, V>;
mapChain<T extends IterableContainer, U, V>(
	fn1: (value: T[number]) => U,
	fn2: (value: U, index: number) => V,
): (data: T) => Mapped<T, V>;
mapChain<T extends IterableContainer, U, V>(
	fn1: (value: T[number]) => U,
	fn2: (value: U) => V,
): (data: T) => Mapped<T, V>;
...
...

import { mapFn } from './map.js';

export function mapChain(...fns) {
  return list => {
		let result = list.slice()
		fns.forEach((fn) => {
			result = mapFn(fn, result)
		})
		return result
	}
}

import { mapChain } from './mapChain.js'

const double = x => x * 2

it('happy', () => {
  expect(mapChain(double, double, double)([1, 2, 3])).toEqual([8, 16, 24])
})

import { mapChain, pipe } from 'rambda'

const list = [1, 2, 3]

it('R.mapChain', () => {
  const result = pipe(
    list,
    mapChain(
      x => {
        x // $ExpectType number
        return String(x)
      },
      x => {
        x // $ExpectType string
        return x !== 'foo'
      },
    ),
  )
  result // $ExpectType boolean[]
})

it('R.mapChain - with index', () => {
  const result = pipe(
    list,
    mapChain(
      x => {
        x // $ExpectType number
        return String(x)
      },
      (x, i) => {
        i // $ExpectType number
        x // $ExpectType string
        return x !== 'foo'
      },
    ),
  )
  result // $ExpectType boolean[]
})

it('R.mapChain - 3 functions', () => {
  const result = pipe(
    list,
    x => x,
    mapChain(
      x => {
        x // $ExpectType number
        return String(x)
      },
      x => {
        x // $ExpectType string
        return x !== 'foo'
      },
      x => {
        x // $ExpectType boolean
        return x ? 'foo' : 'bar'
      },
    ),
  )
  result // $ExpectType ("foo" | "bar")[]
})

mapKeys<T>(fn: (prop: string, value: T) => string): (obj: Record<string, T>) => Record<string, T>;

export function mapKeys(fn) {
  return obj => {
		const willReturn = {}

		Object.keys(obj).forEach(key => {
			willReturn[fn(key, obj[key])] = obj[key]
		})

		return willReturn
	}
}

import { mapKeys } from './mapKeys.js'

test('happy', () => {
	const result = mapKeys((prop, x) => `${ prop }-${x}`)({a:1, b: 2 })
	const expected = { 'a-1': 1, 'b-2': 2 }

	expect(result).toEqual(expected)
})

import { mapKeys, pipe } from 'rambda'

it('R.mapKeys', () => {
  const result = pipe(
    { a: 1, b: 2 },
    mapKeys((prop, x) => `${prop}-${x}`),
    mapKeys(prop => `${prop}-${prop}`),
  )
  result // $ExpectType Record<string, number>
})

mapObject<T extends object, Value>(
  valueMapper: (
    value: EnumerableStringKeyedValueOf<T>,
    key: EnumerableStringKeyOf<T>,
    data: T,
  ) => Value,
): (data: T) => MappedValues<T, Value>;

import { keys } from './_internals/keys.js'

export function mapObject(fn) {
  return obj => {
    let index = 0
    const objKeys = keys(obj)
    const len = objKeys.length
    const willReturn = {}

    while (index < len) {
      const key = objKeys[index]
      willReturn[key] = fn(obj[key], key, obj)
      index++
    }

    return willReturn
  }
}

import { mapObject } from './mapObject.js'

const double = x => x * 2

it('happy', () => {
  expect(mapObject(double)({ a: 1, b: 2, c: 3 })).toEqual({ a: 2, b: 4, c: 6 })
})

import { mapObject, pipe } from 'rambda'

describe('R.mapObject', () => {
  it('iterable with one arguments', () => {
    const result = pipe(
      { a: 1 },
      mapObject(a => {
        a // $ExpectType number
        return `${a}`
      }),
    )

    result // $ExpectType { a: string; }
  })
  it('iterable with one arguments', () => {
    const result = pipe(
      { a: [1,2,3], b: 'foo' },
      mapObject(a => {
        a // $ExpectType string | number[]
        return typeof a as string
      }),
    )

    result // $ExpectType { a: string; b: string; }
  })
  it('iterable with two arguments', () => {
    const result = pipe(
      { a: 1, b: 'foo' },
      mapObject((a, b) => {
        a // $ExpectType string | number
        b // $ExpectType "a" | "b"
        return `${a}`
      }),
    )

    result // $ExpectType { a: string; b: string; }
  })
  it('iterable with three arguments', () => {
    const result = pipe(
      { a: 1, b: 'foo' },
      mapObject((a, b, c) => {
        a // $ExpectType string | number
        b // $ExpectType "a" | "b"
        c // $ExpectType { a: number; b: string; }
        return `${a}`
      }),
    )

    result // $ExpectType { a: string; b: string; }
  })
})

mapObjectAsync<T extends object, Value>(
  valueMapper: (
    value: EnumerableStringKeyedValueOf<T>,
    key: EnumerableStringKeyOf<T>,
    data: T,
  ) => Promise<Value>,
): (data: T) => Promise<MappedValues<T, Value>>;

export function mapObjectAsync(fn) {
  return async obj => {
    const willReturn = {}
    for (const prop in obj) {
      willReturn[prop] = await fn(obj[prop], prop)
    }

    return willReturn
  }
}

import { delay } from './delay.js'
import { mapObjectAsync } from './mapObjectAsync.js'
import { pipeAsync } from './pipeAsync.js'

test('happy', async () => {
  const indexes = []
  const result = await pipeAsync(
    { a: 1, b: 2 },
    mapObjectAsync(async (x, i) => {
      await delay(100)
      indexes.push(i)
      return x + 1
    }),
  )
  expect(indexes).toEqual(['a', 'b'])
  expect(result).toEqual({
    a: 2,
    b: 3,
  })
})

import { mapObjectAsync, pipeAsync } from 'rambda'
import { delay } from 'rambdax'

it('R.mapObjectAsync', async () => {
  const result = await pipeAsync(
    { a: 'foo', b: 'bar' },
    mapObjectAsync(async x => {
      await delay(100)
      x // $ExpectType string
      return x.length % 2 ? x.length + 1 : x.length + 10
    }),
    x => x,
    mapObjectAsync(async x => {
      await delay(100)
      return x + 1
    }),
  )
  result.a // $ExpectType number
  result.b // $ExpectType number
})

mapParallelAsync<T extends IterableContainer, U>(
  fn: (value: T[number]) => Promise<U>,
	batchSize?: number,
): (data: T) => Promise<Mapped<T, U>>;

export function mapParallelAsync(fn, batchSize){
	if(!batchSize) return async list =>  Promise.all(list.map(fn))

	return async list => {
		const result = []
		for(let i = 0; i < list.length; i += batchSize){
			const batch = list.slice(i, i + batchSize)
			const batchResult = await Promise.all(batch.map((x, j) => fn(x, i + j)))
			result.push(...batchResult)
		}
		return result
	}	
}

import { pipeAsync } from './pipeAsync.js'
import { delay } from './delay.js'
import { mapParallelAsync } from './mapParallelAsync.js'

test('happy', async () => {
  const fn = async (x, i) => {
    await delay(100)

    return x + i
  }
  const result = await mapParallelAsync(fn)([ 1, 2, 3 ])
  expect(result).toEqual([ 1, 3, 5 ])
})

test('pipeAsync', async () => {
  const result = await pipeAsync(
		[1, 2, 3],
    mapParallelAsync(async x => {
      await delay(100)

      return x + 1
    })
	)
  expect(result).toEqual([ 2,3,4 ])
})

test('with batchSize', async () => {
	const fn = async (x, i) => {
		await delay(100)
		return `${x}:${i}`
	}
	const result = await mapParallelAsync(fn, 2)([1, 2, 3, 4, 5])
	expect(result).toEqual(
		['1:0', '2:1', '3:2', '4:3', '5:4']
	)
})

mapPropObject<T extends object, K extends keyof T, Value extends unknown>(
	prop: K,
	valueMapper: (
		listItem: T[K] extends ReadonlyArray<infer ElementType> ? ElementType : never,
		list: T[K] extends ReadonlyArray<any> ? T[K] : never,
	) => Value,
): (data: T) => T[K] extends ReadonlyArray<any>
	? MergeTypes<Omit<T, K> & { [P in K]: Value[] }>
	: never;
mapPropObject<T extends object, K extends keyof T, Value extends unknown>(
	prop: K,
  valueMapper: (
    listItem: T[K] extends ReadonlyArray<infer ElementType> ? ElementType : never,
  ) => Value,
): (data: T) => T[K] extends ReadonlyArray<any>
  ? MergeTypes<Omit<T, K> & { [P in K]: Value[] }>
  : never;

export function mapPropObject(fn, prop) {
  return obj => {
		if (!Array.isArray(obj[prop])) return obj
			
			return {
				...obj,
				[prop]: obj[prop].map(fn)
			}
		}
 	 }

import { mapPropObject } from './mapPropObject.js'
import { pipe } from './pipe.js'

it('happy', () => {
  const result = pipe(
    { a: [1, 2, 3], b: 'foo' },
    mapPropObject(x => ({ a: x, flag: x > 2 }), 'a'),
  )

  expect(result).toEqual({
    a: [
      { a: 1, flag: false },
      { a: 2, flag: false },
      { a: 3, flag: true },
    ],
    b: 'foo',
  })
})

import {  map, mapPropObject, pipe } from 'rambda'

describe('R.mapPropObject', () => {
  it('iterable with one arguments', () => {
    const result = pipe(
      { a: [1,2,3], b: 'foo' },
      mapPropObject('a', x => {
        x // $ExpectType number
        return {
          a: x,
          flag: x > 2,
        }
      }),
    )

    result.a // $ExpectType { a: number; flag: boolean; }[]
		result.b // $ExpectType string
  })

  it('iterable with two arguments', () => {
    const result = pipe(
      { a: [1,2,3], b: 'foo' },
      mapPropObject('a', (x, list) => {
        x // $ExpectType number
        list // $ExpectType number[]
				return list.length
      }),
    )
		result.a // $ExpectType number[]
		result.b // $ExpectType string
  })

  it('more complex example', () => {
    const result = pipe(
      [{a:[true, false, true], b: 'foo'}],
      map(
					mapPropObject( 'a',(a) => {
						a // $ExpectType boolean
						return {a, b: 2}
								})
					)
			)

    result[0].a[0].a // $ExpectType boolean
    result[0].a[0].b // $ExpectType number
  })
})

match(regExpression: RegExp): (str: string) => string[];

export function match(pattern) {
  return input => {
    const willReturn = input.match(pattern)

    return willReturn === null ? [] : willReturn
  }
}

import { match } from './match.js'

test('happy', () => {
  expect(match(/a./g)('foo bar baz')).toEqual(['ar', 'az'])
})

test('fallback', () => {
  expect(match(/a./g)('foo')).toEqual([])
})

test('with string', () => {
  expect(match('a')('foo')).toEqual([])
})

import { match } from 'rambda'

const str = 'foo bar'

describe('R.match', () => {
  it('happy', () => {
    const result = match(/foo/)(str)
    result // $ExpectType string[]
  })
})

maxBy<T>(compareFn: (input: T) => Ord, x: T): (y: T) => T;

export function maxBy(compareFn, x) {
  return y => (compareFn(y) > compareFn(x) ? y : x)
}

import { maxBy } from './maxBy.js'

test('happy', () => {
  expect(maxBy(Math.abs, 2)(-5)).toBe(-5)
  expect(maxBy(Math.abs, -5)(2)).toBe(-5)
})

import { maxBy, pipe } from 'rambda'

const first = 1
const second = 2

it('R.maxBy', () => {
  const result = pipe(
    second,
    maxBy(x => (x % 2 === 0 ? 1 : -1), first),
  )
  result // $ExpectType number
})

merge<Source>(source: Source): <T>(data: T) => Merge<T, Source>;

export function merge(target) {
  return objectWithNewProps =>
    Object.assign({}, target || {}, objectWithNewProps || {})
}

import { merge } from './merge.js'

const obj = {
  foo: 1,
  bar: 2,
}

test('happy', () => {
  expect(merge(obj)({ bar: 20 })).toEqual({
    foo: 1,
    bar: 20,
  })
})

import { merge, mergeTypes, pipe } from 'rambda'

it('R.merge', () => {
  const result = pipe({ foo: 1 }, merge({ bar: 2 }), mergeTypes)
  result.foo // $ExpectType number
  result.bar // $ExpectType number
})

mergeTypes<T>(x: T): MergeTypes<T>;

export function mergeTypes(x) {
  return x
}

middle<T extends unknown>(input: T): T extends unknown[] ? 
	T['length'] extends 0 ? [] : T['length'] extends 1 ? [] : T['length'] extends 2 ? [] : 
	T extends [any, ...infer U, any] ? U : T : T extends string ? string : never;

import { init } from './init.js'
import { tail } from './tail.js'

export function middle(listOrString) {
  return tail(init(listOrString))
}

import { middle } from './middle'

test('middle', () => {
  expect(middle([1, 2, 3])).toEqual([2])
  expect(middle([1, 2])).toEqual([])
  expect(middle([1])).toEqual([])
  expect(middle([])).toEqual([])

  expect(middle('abc')).toBe('b')
  expect(middle('ab')).toBe('')
  expect(middle('a')).toBe('')
  expect(middle('')).toBe('')
})

import { map, middle, pipe } from 'rambda'

describe('R.middle', () => {
  it('with string', () => {
    const result = middle('foo')

    result // $ExpectType string
  })
  it('with list - using const on short array', () => {
    const result = pipe(
      [1, 2] as const,
      map(x => x * 2),
      middle,
    )
    result // $ExpectType []
  })
  it('with list - using const on empty array', () => {
    const result = pipe(
      [] as const,
      map(x => x * 2),
      middle,
    )
    result // $ExpectType []
  })
  it('with list - using const', () => {
    const result = pipe(
      [1, 2, 3, 4] as const,
      map(x => x * 2),
      middle,
    )
    result // $ExpectType [number, number]
  })
  it('with list - mixed types', () => {
    const result = middle(['foo', 'bar', 1, 2, 3])

    result // $ExpectType (string | number)[]
  })
})

minBy<T>(compareFn: (input: T) => Ord, x: T): (y: T) => T;

export function minBy(compareFn, x) {
  return y => (compareFn(y) < compareFn(x) ? y : x)
}

import { minBy } from './minBy.js'

test('happy', () => {
  expect(minBy(Math.abs, -5)(2)).toBe(2)
  expect(minBy(Math.abs, 2)(-5)).toBe(2)
})

modifyItemAtIndex<T>(index: number, replaceFn: (x: T) => T): (list: T[]) => T[];

import { cloneList } from './_internals/cloneList.js'

export function modifyItemAtIndex(index, replaceFn) {
  return list => {
    const actualIndex = index < 0 ? list.length + index : index
    if (index >= list.length || actualIndex < 0) {
      return list
    }

    const clone = cloneList(list)
    clone[actualIndex] = replaceFn(clone[actualIndex])

    return clone
  }
}

import { modifyItemAtIndex } from './modifyItemAtIndex.js'

const add10 = x => x + 10

const list = [0, 1, 2]
const expected = [0, 11, 2]

test('happy', () => {
  expect(modifyItemAtIndex(1, add10)(list)).toEqual(expected)
})

test('with negative index', () => {
  expect(modifyItemAtIndex(-2, add10)(list)).toEqual(expected)
})

test('when index is out of bounds', () => {
  const list = [0, 1, 2, 3]
  expect(modifyItemAtIndex(4, add10)(list)).toEqual(list)
  expect(modifyItemAtIndex(-5, add10)(list)).toEqual(list)
})

modifyPath<U, T>(path: [], fn: (value: U) => T): (obj: U) => T;
modifyPath<
  K0 extends keyof U,
  U,
  T
>(path: [K0], fn: (value: U[K0]) => T): (obj: U) => DeepModify<[K0], U, T>;
modifyPath<
  K0 extends string & keyof U,
  U,
  T
>(path: `${K0}`, fn: (value: U[K0]) => T): (obj: U) => DeepModify<[K0], U, T>;
modifyPath<
  K0 extends keyof U,
  K1 extends keyof U[K0],
  U,
  T
>(path: [K0, K1], fn: (value: U[K0][K1]) => T): (obj: U) => DeepModify<[K0, K1], U, T>;
...
...

import { createPath } from './_internals/createPath.js'
import { path as pathModule } from './path.js'

function assoc(prop, newValue) {
  return obj => Object.assign({}, obj, { [prop]: newValue })
}

function modifyPathFn(pathInput, fn, obj) {
  const path = createPath(pathInput)
  if (path.length === 1) {
    return {
      ...obj,
      [path[0]]: fn(obj[path[0]]),
    }
  }
  if (pathModule(path)(obj) === undefined) {
    return obj
  }

  const val = modifyPathFn(Array.prototype.slice.call(path, 1), fn, obj[path[0]])
  if (val === obj[path[0]]) {
    return obj
  }

  return assoc(path[0], val)(obj)
}

export function modifyPath(pathInput, fn) {
  return obj => modifyPathFn(pathInput, fn, obj)
}

import { modifyPath } from './modifyPath.js'

const obj = { a: { b: { c: 1 } } }

test('happy', () => {
  const result = modifyPath('a.b.c', x => x + 1)(obj)
  expect(result).toEqual({ a: { b: { c: 2 } } })
})

test('works only on existing paths', () => {
  const result = modifyPath('a.b.d', x => x + 1)(obj)
  expect(result).toEqual(obj)
})

import { modifyPath, pipe } from 'rambda'

const obj = { a: { b: { c: 1 } } }

describe('R.modifyPath', () => {
  it('array path', () => {
    const result = pipe(
      obj,
      modifyPath(['a', 'b', 'c'], (x: number) => String(x)),
    )
    result.a.b.c // $ExpectType string
  })
  it('string path', () => {
    const result = pipe(
      obj,
      modifyPath('a.b.c', (x: number) => String(x)),
    )
    result.a.b.c // $ExpectType string
  })
})

modifyProp<T, K extends keyof T>(
  prop: K,
  fn: (x: T[K]) => T[K],
): (target: T) => T;

import { isArray } from './_internals/isArray.js'
import { update } from './update.js'

function modifyFn(property, fn, list) {
  if (list[property] === undefined) {
    return list
  }
  if (isArray(list)) {
    return update(property, fn(list[property]))(list)
  }

  return {
    ...list,
    [property]: fn(list[property]),
  }
}

export function modifyProp(property, fn) {
  return obj => modifyFn(property, fn, obj)
}

import { modifyProp } from './modifyProp.js'

const person = {
  name: 'foo',
  age: 20,
}

test('happy', () => {
  expect(modifyProp('age', x => x + 1)(person)).toEqual({
    name: 'foo',
    age: 21,
  })
})

test('property is missing', () => {
  expect(modifyProp('foo', x => x + 1)(person)).toEqual(person)
})

test('adjust if `array` at the given key with the `transformation` function', () => {
  expect(modifyProp(1, x => x + 1)([100, 1400])).toEqual([100, 1401])
})

import { modifyProp, pipe } from 'rambda'

it('R.modify', () => {
  const result = pipe(
    { a: 1, b: 2, c: { d: 3 } },
    modifyProp('a', val => val + 1),
  )
  result // $ExpectType { a: number; b: number; c: { d: number; }; }

  pipe(
    { a: 1, b: 2, c: { d: 3 } },
    // @ts-expect-error
    modifyProp('ax', val => val + 1),
  )

  pipe(
    { a: 1, b: 2, c: { d: 3 } },
    // @ts-expect-error
    modifyProp('a', val => String(val)),
  )
})

none<T>(predicate: (x: T) => boolean): (list: T[]) => boolean;

export function none(predicate) {
  return list => {
    for (let i = 0; i < list.length; i++) {
      if (predicate(list[i])) {
        return false
      }
    }

    return true
  }
}

import { none } from './none.js'

const isEven = n => n % 2 === 0

test('when true', () => {
  expect(none(isEven)([1, 3, 5, 7])).toBeTruthy()
})

test('when false', () => {
  expect(none(input => input > 1)([1, 2, 3])).toBeFalsy()
})

import { none, pipe } from 'rambda'

describe('R.none', () => {
  it('happy', () => {
    const result = pipe(
      [1, 2, 3],
      none(x => x > 0),
    )
    result // $ExpectType boolean
  })
})

objectIncludes<T>(specification: T): (obj: Partial<T>) => boolean;

import { equals } from './equals.js'
import { filterObject } from './filterObject.js'

export function objectIncludes(condition) {
  return obj => {
    const result = filterObject((conditionValue, conditionProp) =>
      equals(conditionValue)(obj[conditionProp]),
    )(condition)

    return Object.keys(result).length === Object.keys(condition).length
  }
}

import { objectIncludes } from './objectIncludes.js'

test('when true', () => {
  const condition = { a: 1 }
  const input = {
    a: 1,
    b: 2,
  }

  const result = objectIncludes(condition)(input)
  const expectedResult = true

  expect(result).toEqual(expectedResult)
})

test('when false', () => {
  const condition = { a: 1 }
  const input = { b: 2 }

  const result = objectIncludes(condition)(input)
  const expectedResult = false

  expect(result).toEqual(expectedResult)
})

test('with nested object', () => {
  const condition = { a: { b: 1 } }
  const input = {
    a: { b: 1 },
    c: 2,
  }

  const result = objectIncludes(condition)(input)
  const expectedResult = true

  expect(result).toEqual(expectedResult)
})

test('with wrong input', () => {
  const condition = { a: { b: 1 } }

  expect(() => objectIncludes(condition)(null)).toThrowErrorMatchingInlineSnapshot(
    `[TypeError: Cannot read properties of null (reading 'a')]`,
  )
})

import { objectIncludes, pipe } from 'rambda'

describe('R.objectIncludes', () => {
  it('happy', () => {
    const result = pipe({ a: 1, b: 2, c: { d: 3 } }, objectIncludes({ a: 2 }))
    result // $ExpectType boolean
  })
  it('nested', () => {
    const result = pipe({ a: 1, b: 2, c: { d: 3 } }, objectIncludes({ c: { d: 3 } }))
    result // $ExpectType boolean
  })
})

objOf<T, K extends PropertyKey>(key: K): (value: T) => { [P in K]: T };

export function objOf(key) {
  return value => ({ [key]: value })
}

import { objOf } from './objOf.js'

test('happy', () => {
  expect(objOf('foo')(42)).toEqual({ foo: 42 })
})

import { objOf, pipe } from 'rambda'

const key = 'foo'
const value = 42

it('R.objOf', () => {
  const result = pipe(value, objOf(key))
  result.foo // $ExpectType number
  // @ts-expect-error
  result.bar
})

omit<
	S extends string,
	Keys extends PickStringToPickPath<S>,
>(propsToPick: S): <U extends Partial<Record<ElementOf<Keys>, any>>>(
	obj: ElementOf<Keys> extends keyof U ? U : never
) => ElementOf<Keys> extends keyof U ? MergeTypes<Omit<U, ElementOf<Keys>>> : never;
omit<const Keys extends PropertyKey[]>(propsToPick: Keys): <
	U extends Partial<Record<ElementOf<Keys>, any>>
>(
	obj: ElementOf<Keys> extends keyof U ? U : never
) => ElementOf<Keys> extends keyof U ? MergeTypes<Omit<U, ElementOf<Keys>>> : never;

import { createPath } from './_internals/createPath.js'

export function _includes(x, list) {
  let index = -1
  const { length } = list

  while (++index < length) {
    if (String(list[index]) === String(x)) {
      return true
    }
  }

  return false
}

export function omit(propsToOmit) {
  return obj => {
    if (!obj) {
      return undefined
    }

    const propsToOmitValue = createPath(propsToOmit, ',')
    const willReturn = {}

    for (const key in obj) {
      if (!_includes(key, propsToOmitValue)) {
        willReturn[key] = obj[key]
      }
    }

    return willReturn
  }
}

import { omit } from './omit.js'

test('with string as condition', () => {
  const obj = {
    a: 1,
    b: 2,
    c: 3,
  }
  const result = omit('a,c')(obj)
  const expectedResult = { b: 2 }

  expect(result).toEqual(expectedResult)
})

test('with array as condition', () => {
  expect(
    omit(['a', 'c', 'd'])({
      a: 'foo',
      b: 'bar',
      c: 'baz',
    }),
  ).toEqual({ b: 'bar' })
})

import { omit, pipe } from 'rambda'

const input = { a: 'foo', b: 2, c: 3 }

describe('R.omit', () => {
  it('with string as input', () => {
    const result = pipe(input, omit('a,b'))
    result.c // $ExpectType number
  })
  it('with array as input', () => {
    const result = pipe(input, omit(['a', 'b']))
    result.c // $ExpectType number
  })
})

partition<T, S extends T>(
  predicate: (value: T, index: number, data: ReadonlyArray<T>) => value is S,
): (data: ReadonlyArray<T>) => [Array<S>, Array<Exclude<T, S>>];
partition<T>(
  predicate: (value: T, index: number, data: ReadonlyArray<T>) => boolean,
): (data: ReadonlyArray<T>) => [Array<T>, Array<T>];

export function partition(predicate) {
  return list => {
		const yes = []
		const no = []
		let counter = -1
	
		while (counter++ < list.length - 1) {
			if (predicate(list[counter], counter)) {
				yes.push(list[counter])
			} else {
				no.push(list[counter])
			}
		}
	
		return [yes, no]
  }
}

import { partition } from './partition.js'

test('happy', () => {
  const list = [1, 2, 3]
  const predicate = x => x > 2

  const result = partition(predicate)(list)
  expect(result).toEqual([[3], [1, 2]])
})

import { partition, pipe } from 'rambda'

describe('R.partition', () => {
  it('happy', () => {
    const predicate = (x: number) => {
      return x > 2
    }
    const list = [1, 2, 3, 4]

    const result = pipe(list, partition(predicate))
    result // $ExpectType [number[], number[]]
  })
  it('with simple object', () => {
    const result = pipe(
      [{ a: 1 }, { a: 2 }, { a: 3 }, { a: 4 }],
      partition(x => x.a > 2),
    )
    result // $ExpectType [{ a: number; }[], { a: number; }[]]
  })
  it('with complex object', () => {
    interface Foo {
      a: number
    }
    interface Bar {
      b: number
    }
    const list1: (Foo | Bar)[] = [{ a: 1 }, { b: 2 }, { a: 3 }, { b: 4 }]
    const filterFoo = (x: Foo | Bar): x is Foo => 'a' in x
    const result = pipe(list1, partition(filterFoo))
    result // $ExpectType [Foo[], Bar[]]
  })
})

partitionObject<T extends unknown, S extends T>(
  predicate: (value: T, prop: string, obj: Record<string, T>) => value is S,
): (obj: Record<string, T>) => [Record<string, S>, Record<string, Exclude<T, S>>];
partitionObject<T extends unknown>(
  predicate: (value: T, prop: string, obj: Record<string, T>) => boolean,
): (obj: Record<string, T>) => [Record<string, T>, Record<string, T>];

export function partitionObject(predicate) {
	return obj => {
  const yes = {}
  const no = {}
  Object.entries(obj).forEach(([prop, value]) => {
    if (predicate(value, prop)) {
      yes[prop] = value
    } else {
      no[prop] = value
    }
  })

  return [yes, no]
}
}

import { partitionObject } from './partitionObject.js'

test('happy', () => {
  const predicate = (value, prop) => {
    expect(typeof prop).toBe('string')

    return value > 2
  }
  const hash = {
    a: 1,
    b: 2,
    c: 3,
    d: 4,
  }

  const result = partitionObject(predicate)(hash)
  const expectedResult = [
    {
      c: 3,
      d: 4,
    },
    {
      a: 1,
      b: 2,
    },
  ]

  expect(result).toEqual(expectedResult)
})

import { partitionObject, pipe } from 'rambda'

describe('R.partition', () => {
  it('happy', () => {
		let result = pipe(
			{ a: 1, b: 2 },
			partitionObject((x, prop) => x> 1 || prop === 'c'),
		)
    result // $ExpectType [Record<string, number>, Record<string, number>]
  })
  it('with complex object', () => {
    interface Foo {
      a: number
    }
    interface Bar {
      b: number
    }
    const obj: Record<string, (Foo | Bar)> = {
			a: { a: 1 },
			b: { b: 2 },
			c: { a: 3 },
			d: { b: 4 },
		}
    const filterFoo = (x: Foo | Bar): x is Foo => 'a' in x
    const result = pipe(obj, partitionObject(filterFoo))
    result // $ExpectType [Record<string, Foo>, Record<string, Bar>]
  })
})

path<S, K0 extends string & keyof S>(path: `${K0}`): (obj: S) => S[K0];
path<S, K0 extends string & keyof S, K1 extends string & keyof S[K0]>(path: `${K0}.${K1}`): (obj: S) => S[K0][K1];
path<
  S,
  K0 extends keyof S,
  K1 extends keyof S[K0],
  K2 extends keyof S[K0][K1]
>(path: [K0, K1, K2]): (obj: S) => S[K0][K1][K2];
path<
  S,
  K0 extends string & keyof S,
  K1 extends string & keyof S[K0],
  K2 extends string & keyof S[K0][K1]
>(path: `${K0}.${K1}.${K2}`): (obj: S) => S[K0][K1][K2];
...
...

import { createPath } from './_internals/createPath.js'

export function path(pathInput) {
	return (obj)  => {
		if (!obj) {
			return undefined
		}
		let willReturn = obj
		let counter = 0
	
		const pathArrValue = createPath(pathInput)
	
		while (counter < pathArrValue.length) {
			if (willReturn === null || willReturn === undefined) {
				return undefined
			}
			if (willReturn[pathArrValue[counter]] === null) {
				return undefined
			}
	
			willReturn = willReturn[pathArrValue[counter]]
			counter++
		}
	
		return willReturn
	}
}

import { path } from './path.js'

test('with array inside object', () => {
  const obj = { a: { b: [1, { c: 1 }] } }

  expect(path('a.b.1.c')(obj)).toBe(1)
})

test('works with undefined', () => {
  const obj = { a: { b: { c: 1 } } }

  expect(path('a.b.c.d.f')(obj)).toBeUndefined()
  expect(path('foo.babaz')(undefined)).toBeUndefined()
  expect(path('foo.babaz')(undefined)).toBeUndefined()
})

test('works with string instead of array', () => {
  expect(path('foo.bar.baz')({ foo: { bar: { baz: 'yes' } } })).toBe('yes')
})

test('path', () => {
  expect(path(['foo', 'bar', 'baz'])({ foo: { bar: { baz: 'yes' } } })).toBe('yes')
  expect(path(['foo', 'bar', 'baz'])(null)).toBeUndefined()
  expect(path(['foo', 'bar', 'baz'])({ foo: { bar: 'baz' } })).toBeUndefined()
})

test('with number string in between', () => {
  expect(path(['a', '1', 'b'])({ a: [{ b: 1 }, { b: 2 }] })).toBe(2)
})

test('null is not a valid path', () => {
  expect(
    path('audio_tracks')({
      a: 1,
      audio_tracks: null,
    }),
  ).toBeUndefined()
})

import { path, pipe } from 'rambda'

const input = { a: { b: { c: true } } }

describe('R.path with string as path', () => {
  it('happy', () => {
    const result = pipe(input, path(['a', 'b']))
    const resultStringInput = pipe(input, path('a.b.c'))
    result.c // $ExpectType boolean
    resultStringInput // $ExpectType boolean
  })
  it('happy', () => {
    const result = pipe([1, 2, 3], path([1]))
    result // $ExpectType number
  })
})

pathSatisfies<S, K0 extends string & keyof S>(
  predicate: (x: S[K0]) => boolean,
  path: [K0]
): (obj: S) => boolean;
pathSatisfies<S, K0 extends string & keyof S>(
  predicate: (x: S[K0]) => boolean,
  path: `${K0}`
): (obj: S) => boolean;
pathSatisfies<S, K0 extends string & keyof S, K1 extends string & keyof S[K0]>(
  predicate: (x: S[K0][K1]) => boolean,
  path: [K0, K1]
): (obj: S) => boolean;
pathSatisfies<S, K0 extends string & keyof S, K1 extends string & keyof S[K0]>(
  predicate: (x: S[K0][K1]) => boolean,
  path: `${K0}.${K1}`
): (obj: S) => boolean;
...
...

import { path } from './path.js'

export function pathSatisfies(fn, pathInput) {
  return obj => Boolean(fn(path(pathInput)(obj)))
}

import { pathSatisfies } from './pathSatisfies.js'

const isPositive = n => n > 0

it('returns true if the specified object path satisfies the given predicate', () => {
  expect(pathSatisfies(isPositive, ['x', 'y'])({ x: { y: 1 } })).toBe(true)
})

it('returns false if the specified path does not exist', () => {
  expect(pathSatisfies(isPositive, ['x', 'y'])({ x: { z: 42 } })).toBe(false)
  expect(pathSatisfies(isPositive, 'x.y')({ x: { z: 42 } })).toBe(false)
})

it('returns false otherwise', () => {
  expect(pathSatisfies(isPositive, ['x', 'y'])({ x: { y: 0 } })).toBe(false)
})

import { pathSatisfies, pipe } from 'rambda'

const input = { a: { b: { c: 'bar' } } }

describe('R.pathSatisfies', () => {
  it('happy', () => {
    const result = pipe(
      input,
      pathSatisfies(
        x => {
          x // $ExpectType string
          return x !== 'foo'
        },
        ['a', 'b', 'c'],
      ),
    )
    const resultStringInput = pipe(
      input,
      pathSatisfies(x => {
        x // $ExpectType string
        return x !== 'foo'
      }, 'a.b.c'),
    )
    result // $ExpectType boolean
    resultStringInput // $ExpectType boolean
  })
})

permutations<T>(list: T[]): T[][];

import { cloneList } from './_internals/cloneList.js'

/**
 * Source:
 * https://github.com/denoland/std/blob/main/collections/permutations.ts
 */
export function permutations(inputArray) {
  const result = [];
  const array = cloneList(inputArray);
  const k = array.length;
  if (k === 0) {
    return result;
  }

  const c = new Array(k).fill(0);

  result.push([...array]);

  let i = 1;

  while (i < k) {
    if (c[i] < i) {
      if (i % 2 === 0) {
        [array[0], array[i]] = [array[i], array[0]]
      } else {
        [array[c[i]], array[i]] = [array[i], array[c[i]]]
      }

      result.push([...array]);

      c[i] += 1;
      i = 1;
    } else {
      c[i] = 0;
      i += 1;
    }
  }

  return result;
}

pick<K extends PropertyKey>(propsToPick: K[]): <T extends Partial<Record<K, any>>>(input: K extends keyof T ? T : never) => MergeTypes<Pick<T, K>>;
pick<S extends string, Keys extends PickStringToPickPath<S>>(propsToPick: S): <T extends Partial<Record<ElementOf<Keys>, any>>>(input: ElementOf<Keys> extends keyof T ? T : never) => ElementOf<Keys> extends keyof T ? MergeTypes<Pick<T, ElementOf<Keys>>> : never;

import { createPath } from './_internals/createPath.js'

export function pick(propsToPick) {
  return input => {
    if (!input === null) {
      return undefined
    }
    const keys = createPath(propsToPick, ',')
    const willReturn = {}
    let counter = 0

    while (counter < keys.length) {
      if (keys[counter] in input) {
        willReturn[keys[counter]] = input[keys[counter]]
      }
      counter++
    }

    return willReturn
  }
}

import { pick } from './pick.js'

const obj = {
  a: 1,
  b: 2,
  c: 3,
}

test('props to pick is a string', () => {
  const result = pick('a,c')(obj)
  const expectedResult = {
    a: 1,
    c: 3,
  }

  expect(result).toEqual(expectedResult)
})

test('when prop is missing', () => {
  const result = pick('a,d,f')(obj)
  expect(result).toEqual({ a: 1 })
})

test('props to pick is an array', () => {
  expect(
    pick(['a', 'c'])({
      a: 'foo',
      b: 'bar',
    }),
  ).toEqual({
    a: 'foo',
  })
})

import { pick, pipe } from 'rambda'

const input = { a: 'foo', c: 3 }

describe('R.pick', () => {
  it('with string as input', () => {
    const result = pipe(input, pick('a,c'))
    result.a // $ExpectType string
    result.c // $ExpectType number
  })
  it('with array as input', () => {
		const result = pipe(input, pick(['a', 'c']))
    result.a // $ExpectType string
    result.c // $ExpectType number
  })
	it('throws error if some keys do not exist', () => {
		// @ts-expect-error
		pipe(input, pick('a,c,b,o'))
	})
})

pipe<A, B>(value: A, op1: (input: A) => B): B;
pipe<A, B, C>(
  value: A,
  op1: (input: A) => B,
  op2: (input: B) => C,
): C;
pipe<A, B, C, D>(
  value: A,
  op1: (input: A) => B,
  op2: (input: B) => C,
  op3: (input: C) => D,
): D;
pipe<A, B, C, D, E>(
  value: A,
  op1: (input: A) => B,
  op2: (input: B) => C,
  op3: (input: C) => D,
  op4: (input: D) => E,
): E;
...
...

import { reduce } from './reduce.js'

export function _arity(n, fn) {
  switch (n) {
    case 0:
      return function () {
        return fn.apply(this, arguments)
      }
    case 1:
      return function (a0) {
        return fn.apply(this, arguments)
      }
    case 2:
      return function (a0, a1) {
        return fn.apply(this, arguments)
      }
    case 3:
      return function (a0, a1, a2) {
        return fn.apply(this, arguments)
      }
    case 4:
      return function (a0, a1, a2, a3) {
        return fn.apply(this, arguments)
      }
    case 5:
      return function (a0, a1, a2, a3, a4) {
        return fn.apply(this, arguments)
      }
    case 6:
      return function (a0, a1, a2, a3, a4, a5) {
        return fn.apply(this, arguments)
      }
    case 7:
      return function (a0, a1, a2, a3, a4, a5, a6) {
        return fn.apply(this, arguments)
      }
    case 8:
      return function (a0, a1, a2, a3, a4, a5, a6, a7) {
        return fn.apply(this, arguments)
      }
    case 9:
      return function (a0, a1, a2, a3, a4, a5, a6, a7, a8) {
        return fn.apply(this, arguments)
      }
    case 10:
      return function (a0, a1, a2, a3, a4, a5, a6, a7, a8, a9) {
        return fn.apply(this, arguments)
      }
    default:
      throw new Error(
        'First argument to _arity must be a non-negative integer no greater than ten',
      )
  }
}

function _pipe(f, g) {
  return function () {
    return g.call(this, f.apply(this, arguments))
  }
}

function pipeFn() {
  if (arguments.length === 0) {
    throw new Error('pipe requires at least one argument')
  }

  return _arity(
    arguments[0].length,
    reduce(
      _pipe,
      arguments[0],
    )(Array.prototype.slice.call(arguments, 1, Number.POSITIVE_INFINITY)),
  )
}

export function pipe(...inputs) {
  const [input, ...fnList] = inputs

  return pipeFn(...fnList)(input)
}

import { filter } from './filter.js'
import { map } from './map.js'
import { pipe } from './pipe.js'

test('happy', () => {
  const result = pipe(
    [1, 2, 3],
    filter(x => x > 1),
    map(x => x * 10),
    map(x => x + 1),
  )
  const expectedResult = [21, 31]

  expect(result).toEqual(expectedResult)
})

import {
  type MergeTypes,
  append,
  assertType,
  defaultTo,
  drop,
  dropLast,
  evolve,
  filter,
  find,
  head,
  map,
  pick,
  pipe,
  split,
  union,
} from 'rambda'
type IsNotNever<T> = [T] extends [never] ? false : true
type Expect<T extends true> = T

interface BaseBook {
  title: string
  year: number
  description?: string
  userRating?: number
}
interface Book extends BaseBook {
  awards: {
    number: number
    years?: number[]
  }
  status?: Status
}
interface BookWithBookmarkStatus extends Book {
  bookmarkFlag: boolean
}
interface BookWithReadStatus extends Book {
  readFlag: boolean
}
type BookToRead = BookWithBookmarkStatus & BookWithReadStatus
type FamousBook = Book & {
	status: 'famous'
}

const checkIfFamous = (x: Book): x is FamousBook => {
	return x.status === 'famous'
}
const zaratustra: BaseBook = {
  title: 'Zaratustra',
  year: 1956,
}
const brothersKaramazov = {
  title: 'Brothers Karamazov',
  year: 1880,
}

const awardedZaratustra: Book = {
  ...zaratustra,
  awards: {
    number: 1,
    years: [1956],
  },
}
const awardedBrothersKaramazov: Book = {
  ...brothersKaramazov,
  awards: {
    number: 2,
    years: [1869, 1870],
  },
}
const awardedZaratustraToRead: BookToRead = {
  ...awardedZaratustra,
  readFlag: true,
  bookmarkFlag: true,
}
const awardedBaseValue: Book = {
  title: '',
  year: 0,
  awards: {
    number: 0,
    years: [],
  },
}

type Status = 'famous' | 'can be skipped' | 'must-read'

function checkBookToRead(x: Book): x is BookToRead {
  return (x as BookToRead).readFlag && (x as BookToRead).bookmarkFlag
}

function tapFn<T, U>(
  transformFn: (x: T) => U,
  fn: (a: T, b: U) => void,
): (x: T) => T {
  return x => {
    const result = transformFn(x)
    fn(x, result)
    return x
  }
}

function simplify<T>(x: T) {
  return x as MergeTypes<T>
}

describe('real use cases - books', () => {
  it('case 1', () => {
    const result = pipe(
      [awardedZaratustra, awardedBrothersKaramazov],
      filter(checkIfFamous),
      drop(1),
      // without converting to `as FamousBook`, endsWith will pick up `Book` as type
      tapFn(union([awardedBrothersKaramazov]), (a, b) => {
        a // $ExpectType Book[]
        b // $ExpectType Book[]
      }),
      find(x => {
        x // $ExpectType Book
        return x.title === 'Brothers Karamazov'
      }),
      x => [x],
      filter(Boolean),
    )
    const final: Expect<IsNotNever<typeof result>> = true
  })
  it('case 2', () => {
    const getResult = (book: BaseBook) =>
      pipe(
        book,
        defaultTo(awardedBaseValue),
        assertType(checkBookToRead),
        x => [x],
        dropLast(1),
        append(awardedZaratustraToRead),
        head,
        evolve({
          year: x => x + 1,
        }),
        simplify,
        pick('year'),
      )
    const result = getResult(zaratustra)
    const final: Expect<IsNotNever<typeof result>> = true
  })
  it('case 3', () => {
    const tableData = `id,title,year
		1,The First,2001
		2,The Second,2020
		3,The Third,2018`

    const result = pipe(tableData, split('\n'), map(split(',')))
    result // $ExpectType string[][]
  })
})

it('R.pipe', () => {
  const obj = {
    a: 'foo',
    b: 'bar',
  }

  const result = pipe(
    obj,
    x => ({ a: x.a.length + x.b.length }),
    x => ({ ...x, b: x.a + 'foo' }),
    x => ({ ...x, c: x.b + 'bar' }),
  )

  result.a // $ExpectType number
  result.b // $ExpectType string
  result.c // $ExpectType string
})

pipeAsync<A, B>(input: A, fn0: (x: Awaited<A>) => B) : B;
pipeAsync<A, B, C>(input: A, fn0: (x: Awaited<A>) => B, fn1: (x: Awaited<B>) => C) : C;
pipeAsync<A, B, C, D>(input: A, fn0: (x: Awaited<A>) => B, fn1: (x: Awaited<B>) => C, fn2: (x: Awaited<C>) => D) : D;
pipeAsync<A, B, C, D, E>(input: A, fn0: (x: Awaited<A>) => B, fn1: (x: Awaited<B>) => C, fn2: (x: Awaited<C>) => D, fn3: (x: Awaited<D>) => E) : E;
...
...

import { type } from './type.js'

export async function pipeAsync(input, ...fnList) {
  let willReturn = input
  for (const fn of fnList) {
    const initialResult = fn(willReturn)
    willReturn =
      type(initialResult) === 'Promise' ? await initialResult : initialResult
  }
  return willReturn
}

import { delay } from './delay.js'
import { pipeAsync } from './pipeAsync.js'

const fn1 = x => {
  return new Promise(resolve => {
    resolve(x + 2)
  })
}
const fn2 = async x => {
  await delay(1)

  return x + 3
}

test('happy', async () => {
  const result = await pipeAsync(1, fn1, x => x + 2, fn2)
  expect(result).toBe(8)
})

import { pipeAsync } from 'rambda'
import { delay } from 'rambdax'

describe('R.pipeAsync', () => {
  it('happy', async () => {
    const result = await pipeAsync(
      4,
      async x => {
        x // $ExpectType number
        await delay(100)
        return x + 1
      },
      x => {
        x // $ExpectType number
        return Promise.resolve([x])
      },
    )

    result // $ExpectType number[]
  })
})

pluck<T, K extends keyof T>(property: K): (list: T[]) => T[K][];
pluck<K extends PropertyKey>(prop: K): {
  <U extends O[keyof O], UK extends keyof U, O extends Record<string, any>>(obj: K extends UK ? O : never): { [OK in keyof O]: O[OK][K] };
  <U extends readonly unknown[] | Record<K, any>>(list: readonly U[]): U extends readonly (infer T)[] ? T[] : U extends Record<K, infer T> ? T[] : never;
};
...
...

export function pluck(property) {
  return list => {
    const willReturn = []

    list.forEach(x => {
      if (x[property] !== undefined) {
        willReturn.push(x[property])
      }
    })

    return willReturn
  }
}

import { pluck } from './pluck.js'

test('happy', () => {
  expect(pluck('a')([{ a: 1 }, { a: 2 }, { b: 1 }])).toEqual([1, 2])
})

test('with undefined', () => {
  expect(pluck(undefined)([{ a: 1 }, { a: 2 }, { b: 1 }])).toEqual([])
})

import { pipe, pluck } from 'rambda';

it("R.pluck", () => {
  const input = [
    { a: 1, b: "foo" },
    { a: 2, b: "bar" },
  ];
  const result = pipe(input, pluck("b"));
  result; // $ExpectType string[]
});

it("R.pluck without R.pipe", () => {
  interface Content {
    text: string;
  }
  const content: Content[] = [
    {
      text: "foo",
    },
  ];
  const sentences = pluck("text")(content);
  sentences; // $ExpectType string[]
});

prepend<T>(xToPrepend: T, iterable: T[]): T[];
prepend<T>(xToPrepend: T): (iterable: T[]) => T[];

export function prepend(x) {
  return list => [x].concat(list)
}

import { prepend } from './prepend.js'

test('happy', () => {
  expect(prepend('yes')(['foo', 'bar', 'baz'])).toEqual(['yes', 'foo', 'bar', 'baz'])
})

test('with empty list', () => {
  expect(prepend('foo')([])).toEqual(['foo'])
})

prop<K extends PropertyKey>(prop: K): <U extends { [P in K]?: unknown }>(obj: U) => U[K];
prop<K extends keyof U, U>(prop: K, obj: U): U[K];

export function prop(searchProperty) {
  return obj => (obj ? obj[searchProperty] : undefined)
}

import { map, pipe, prop } from 'rambda'

describe('R.prop', () => {
  it('happy', () => {
    const result = pipe({ a: 1 }, prop('a'))

    result // $ExpectType number
  })
  it('alike R.pluck', () => {
    const result = pipe([{ a: 1 }, { a: 2 }], map(prop('a')))

    result // $ExpectType number[]
  })
})

propEq<T>(val: T): {
  <K extends PropertyKey>(name: K): (obj: Record<K, T>) => boolean;
  <K extends PropertyKey>(name: K, obj: Record<K, T>): boolean;
};
propEq<T, K extends PropertyKey>(val: T, name: K): (obj: Record<K, T>) => boolean;
...
...

import { equalsFn } from './equals.js'

export function propEq(valueToMatch, propToFind) {
  return obj => {
    if (!obj) {
      return false
    }

    return equalsFn(valueToMatch, obj[propToFind])
  }
}

import { propEq } from './propEq.js'

const FOO = 'foo'
const BAR = 'bar'

test('happy', () => {
  const obj = { [FOO]: BAR }
  expect(propEq(BAR, FOO)(obj)).toBeTruthy()
  expect(propEq(1, FOO)(obj)).toBeFalsy()
  expect(propEq(1, 1)(null)).toBeFalsy()
})

test('returns false if called with a null or undefined object', () => {
  expect(propEq('name', 'Abby')(null)).toBeFalsy()
  expect(propEq('name', 'Abby')(undefined)).toBeFalsy()
})

propOr<T, P extends string>(property: P, defaultValue: T): (obj: Partial<Record<P, T>>) => T;

import { defaultTo } from './defaultTo.js'

export function propOr(property, defaultValue) {
  return obj => {
    if (!obj) {
      return defaultValue
    }

    return defaultTo(defaultValue)(obj[property])
  }
}

import { propOr } from './propOr.js'

test('propOr', () => {
  const obj = { a: 1 }
  expect(propOr('a', 'default', )(obj)).toBe(1)
  expect(propOr('notExist', 'default')(obj)).toBe('default')
  expect(propOr('notExist', 'default')(null)).toBe('default')
})

import { propOr } from 'rambda'

const obj = { foo: 'bar' }
const property = 'foo'
const fallback = 'fallback'

it('R.propOr', () => {
	const result = propOr(property, fallback)(obj)
	result // $ExpectType string
})

propSatisfies<T>(predicate: (x: T) => boolean, property: string): (obj: Record<PropertyKey, T>) => boolean;

export function propSatisfies(predicate, property) {
  return obj => predicate(obj[property])
}

import { propSatisfies } from './propSatisfies.js'

const obj = { a: 1 }

test('when true', () => {
  expect(propSatisfies(x => x > 0, 'a')(obj)).toBeTruthy()
})

test('when false', () => {
  expect(propSatisfies(x => x < 0, 'a')(obj)).toBeFalsy()
})

import { pipe, propSatisfies } from 'rambda'

const obj = { a: 1 }

describe('R.propSatisfies', () => {
  it('happy', () => {
    const result = pipe(
      obj,
      propSatisfies(x => {
        x // $ExpectType number
        return x > 0
      }, 'a'),
    )

    result // $ExpectType boolean
  })
})

random(minInclusive: number, maxInclusive: number): number;

export function random(min, max){
  return Math.floor(Math.random() * (max - min + 1)) + min
}

import { random } from './random.js'
import { range } from './range.js'
import { uniq } from './uniq.js'

test('happy', () => {
	const result = uniq(range(100).map(() => random(0, 3))).sort()
  expect(result).toEqual([0,1,2,3])
})

range(endInclusive: number) : number[];
range(startInclusive: number, endInclusive: number) : number[];

export function range(a, b) {
  const start = b === undefined ? 0 : a
  const end = b === undefined ? a : b
  if (end<=  start) {
		return []
  }
  const len = end - start
	return Array.from({ length: len + 1 }, (_, i) => start + i)
}

import { range } from './range.js'

test('happy', () => {
  expect(range(5)).toEqual([0, 1, 2, 3, 4, 5])
  expect(range(3,5)).toEqual([3, 4, 5])
  expect(range(5,3)).toEqual([])
	expect(range(0)).toEqual([])
})

import { range } from 'rambda'

describe('R.range', () => {
  it('curried', () => {
    const result = [range(1, 4), range(1)]

    result // $ExpectType number[][]
  })
})

rangeDescending(startInclusive: number, endInclusive: number) : number[];
rangeDescending(endInclusive: number) : number[];

export function rangeDescending(start, b) {
	const end = b === undefined ? 0 : b
	if (start <= end) {
		return []
	}
  const len = start - end
 	return Array.from({ length: len + 1 }, (_, i) => start - i)
}

import { rangeDescending } from './rangeDescending.js'

test('happy', () => {
  expect(rangeDescending(5)).toEqual([5, 4, 3, 2, 1, 0])
	expect(rangeDescending(7,3)).toEqual([7, 6, 5, 4,3])
	expect(rangeDescending(5, 7)).toEqual([])
	expect(rangeDescending(5, 5)).toEqual([])
})

reduce<T, TResult>(reducer: (prev: TResult, current: T, i: number) => TResult, initialValue: TResult): (list: T[]) => TResult;

import { isArray } from './_internals/isArray.js'

export function reduce(reducer, acc) {
  return list => {
    if (list == null) {
      return acc
    }
    if (!isArray(list)) {
      throw new TypeError('reduce: list must be array or iterable')
    }
    let index = 0
    const len = list.length

    while (index < len) {
      acc = reducer(acc, list[index], index, list)
      index++
    }

    return acc
  }
}

import { concat } from './concat.js'
import { reduce } from './reduce.js'

const reducer = (prev, current, i) => {
  expect(typeof i).toBe('number')

  return prev + current
}
const initialValue = 1
const list = [1, 2, 3]
const ERROR = 'reduce: list must be array or iterable'

test('happy', () => {
  expect(reduce(reducer, initialValue)(list)).toBe(7)
})

test('with undefined as iterable', () => {
  expect(() => reduce(reducer, 0)({})).toThrowError(ERROR)
})

test('returns the accumulator for a null list', () => {
  expect(reduce(concat, [])(null)).toEqual([])
})

test('returns the accumulator for an undefined list', () => {
  expect(reduce(concat, [])(undefined)).toEqual([])
})

import { pipe, reduce } from 'rambda'

it('R.reduce', () => {
  const result = pipe(
    [1, 2, 3],
    reduce((acc, val) => acc + val, 10),
  )
  result // $ExpectType number
})

reject<T>(
	predicate: BooleanConstructor,
): (list: readonly T[]) => ("" | null | undefined | false | 0)[];
reject<T>(
	predicate: BooleanConstructor,
): (list: T[]) => ("" | null | undefined | false | 0)[];
reject<T>(
	predicate: (value: T) => boolean,
): (list: T[]) => T[];

import { filter } from './filter.js'

export function reject(predicate) {
  return list => filter(x => !predicate(x))(list)
}

import { reject } from './reject.js'

test('happy', () => {
  const isEven = n => n % 2 === 0

  expect(reject(isEven)([1, 2, 3, 4])).toEqual([1, 3])
})

import { reject, pipe } from 'rambda'

const list = [1, 2, 3]

describe('R.reject with array', () => {
  it('within pipe', () => {
    const result = pipe(
      list,
      reject(x => {
        x // $ExpectType number
        return x > 1
      }),
    )
    result // $ExpectType number[]
  })
	it('with index', () => {
    const result = pipe(
      list,
      reject((x: number, i: number) => {
        x // $ExpectType number
        i // $ExpectType number
        return x > 1
      }),
    )
    result // $ExpectType number[]
  })
  it('narrowing type', () => {
    interface Foo {
      a: number
    }
    interface Bar extends Foo {
      b: string
    }
    interface Baz extends Foo {
      c: string
    }

    const testList: (Foo | Bar | Baz)[] = [{ a: 1 }, { a: 2 }, { a: 3 }]
    const rejectBar = (x: Foo | Bar | Baz): x is Bar => {
      return typeof (x as Bar).b === 'string'
    }
    const result = pipe(
      testList,
      reject(rejectBar),
    )
    result // $ExpectType (Foo | Baz)[]
  })
  it('narrowing type - readonly', () => {
		interface Foo {
      a: number
    }
    interface Bar extends Foo {
      b: string
    }
    interface Baz extends Foo {
      c: string
    }

    const testList: (Foo | Bar | Baz)[] = [{ a: 1 }, { a: 2 }, { a: 3 }] as const
    const rejectBar = (x: Foo | Bar | Baz): x is Bar => {
      return typeof (x as Bar).b === 'string'
    }
    const result = pipe(
      testList,
      reject(rejectBar),
    )
    result // $ExpectType (Foo | Baz)[]
  })
  it('rejecting NonNullable', () => {
    const testList = [1, 2, null, undefined, 3]
    const result = pipe(testList, reject(Boolean))
    result // $ExpectType (null | undefined)[]
  })
  it('rejecting NonNullable - readonly', () => {
    const testList = [1, 2, null, undefined, 3] as const
    const result = pipe(testList, reject(Boolean))
    result // $ExpectType (null | undefined)[]
    // @ts-expect-error
    result.includes(1)
  })
})

rejectObject<T extends object>(
  valueMapper: (
    value: EnumerableStringKeyedValueOf<T>,
    key: EnumerableStringKeyOf<T>,
    data: T,
  ) => boolean,
): <U extends T>(data: T) => U;

export function rejectObject(predicate) {
  return obj => {
    const willReturn = {}

    for (const prop in obj) {
      if (!predicate(obj[prop], prop, obj)) {
        willReturn[prop] = obj[prop]
      }
    }

    return willReturn
  }
}

import { pipe } from './pipe.js'
import { rejectObject } from './rejectObject.js'

test('happy', () => {
	let testInput = { a: 1, b: 2, c: 3 }
  const result = pipe(
		testInput,
		rejectObject((x, prop, obj) => {
			expect(prop).toBeOneOf(['a', 'b', 'c'])
			expect(obj).toBe(testInput)
			return x > 1
		})
	)
	expect(result).toEqual({ a:1 })
})

import { filterObject, pipe } from 'rambda'

describe('R.filterObject', () => {
  it('require explicit type', () => {
    const result = pipe(
      { a: 1, b: 2 },
      filterObject<{ b: number }>(a => {
        a // $ExpectType number
        return a > 1
      }),
    )
    result.b // $ExpectType number
  })
})

replace(strOrRegex: RegExp | string, replacer: RegExp | string): (str: string) => string;

export function replace(pattern, replacer) {
  return str => str.replace(pattern, replacer)
}

import { replace } from './replace.js'

test('happy', () => {
  expect(replace(/\s/g, '|')('foo bar baz')).toBe('foo|bar|baz')
  expect(replace('a', '|')('foo bar baz')).toBe('foo b|r baz')
})

import { replace } from 'rambda'

const str = 'foo bar foo'
const replacer = 'bar'

describe('R.replace', () => {
  it('happy', () => {
    const result = replace(/foo/g, replacer)(str)

    result // $ExpectType string
  })
  it('with string as search pattern', () => {
    const result = replace('foo', replacer)(str)

    result // $ExpectType string
  })
})

replaceAll(patterns: (RegExp | string)[], replacer: string): (input: string) => string;

export function replaceAll(patterns, replacer) {
  return input => {
    let text = input
    patterns.forEach(singlePattern => {
      text = text.replace(singlePattern, replacer)
    })

    return text
  }
}

import { replaceAll } from './replaceAll.js'

const replacer = '|'
const patterns = [/foo/g, 'bar']
const input = 'foo bar baz foo bar'

test('happy', () => {
  const result = replaceAll(patterns, replacer)(input)
  const expected = '| | baz | bar'

  expect(result).toEqual(expected)
})

import { pipe, replaceAll } from 'rambda'

const str = 'foo bar foo'
const replacer = 'bar'
const patterns = [/foo/g, 'bar']

describe('R.replaceAll', () => {
  it('happy', () => {
    const result = pipe(str, replaceAll(patterns, replacer))

    result // $ExpectType string
  })
})

shuffle<T>(list: T[]): T[];

import { cloneList } from './_internals/cloneList.js'

export function shuffle(listInput) {
  const list = cloneList(listInput)
  let counter = list.length
  while (counter > 0) {
    const index = Math.floor(Math.random() * counter)
    counter--
    const temp = list[counter]
    list[counter] = list[index]
    list[index] = temp
  }

  return list
}

import { shuffle } from 'rambdax'

const list = [1, 2, 3, 4, 5]

describe('R.shuffle', () => {
  it('happy', () => {
    const result = shuffle(list)
    result // $ExpectType number[]
  })
})

sort<T>(sortFn: (a: T, b: T) => number): (list: T[]) => T[];

import { cloneList } from './_internals/cloneList.js'

export function sort(sortFn) {
  return list => cloneList(list).sort(sortFn)
}

import { sort } from './sort.js'

const fn = (a, b) => (a > b ? 1 : -1)

test('sort', () => {
  expect(sort((a, b) => a - b)([2, 3, 1])).toEqual([1, 2, 3])
})

test("it doesn't mutate", () => {
  const list = ['foo', 'bar', 'baz']

  expect(sort(fn)(list)).toEqual(['bar', 'baz', 'foo'])
  expect(list).toEqual(['foo', 'bar', 'baz'])
})

import { pipe, sort } from 'rambda'

const list = [3, 0, 5, 2, 1]

describe('R.sort', () => {
  it('happy', () => {
    const result = sort<number>((a, b) => {
      return a > b ? 1 : -1
    })(list)
    result // $ExpectType number[]
  })
  it('within pipe', () => {
    const result = pipe(
      list,
      sort((a, b) => {
        return a > b ? 1 : -1
      }),
    )
    result // $ExpectType number[]
  })
})

sortBy<T>(sortFn: (x: T) => Ord): (list: T[]) => T[];

import { cloneList } from './_internals/cloneList.js'

export function sortByFn (
	sortFn,
	list,
	descending
){
	const clone = cloneList(list)

	return clone.sort((a, b) => {
		const aSortResult = sortFn(a)
		const bSortResult = sortFn(b)

		if (aSortResult === bSortResult) {
			return 0
		}
		if(
			descending
		) return aSortResult > bSortResult ? -1 : 1

		return aSortResult < bSortResult ? -1 : 1
	})
}

export function sortBy(sortFn) {
  return list => sortByFn(sortFn, list, false)
}

import { sortBy } from './sortBy.js'

const input = [{ a: 2 }, { a: 1 }, { a: 1 }, { a: 3 }]

test('happy', () => {
  const expected = [{ a: 1 }, { a: 1 }, { a: 2 }, { a: 3 }]

  const result = sortBy(x => x.a)(input)
  expect(result).toEqual(expected)
})

test('with non-existing path', () => {
	expect(sortBy(x => x.b)(input)).toEqual(input)
})

import { pipe, sortBy } from 'rambda'

describe('R.sortBy', () => {
  it('passing type to sort function and list', () => {
    const result = pipe(
      [{ a: 2 }, { a: 1 }, { a: 0 }],
      sortBy(x => {
        return x.a
      }),
    )

    result[0].a // $ExpectType number
  })
})

sortByDescending<T>(sortFn: (x: T) => Ord): (list: T[]) => T[];

import { sortByFn } from './sortBy.js';

export function sortByDescending(sortFn) {
  return list => sortByFn(sortFn, list, true)
}

import { sortByDescending } from './sortByDescending.js'
import { path } from './path.js'

const list = [{ a: { b: 3 } }, { a: { b: 1 } }, { a: { b: 2 } }]
const sorted = [{ a: { b: 3 } }, { a: { b: 2 } }, { a: { b: 1 } }]

test('happy', () => {
  expect(sortByDescending(path('a.b'))(list)).toEqual(sorted)
})

sortByPath<S, K0 extends string & keyof S>(
  path: [K0]
): (list: S[]) => S[];
sortByPath<S, K0 extends string & keyof S>(
  path: `${K0}`
): (list: S[]) => S[];
sortByPath<S, K0 extends string & keyof S, K1 extends string & keyof S[K0]>(
  path: [K0, K1]
): (list: S[]) => S[];
sortByPath<S, K0 extends string & keyof S, K1 extends string & keyof S[K0]>(
  path: `${K0}.${K1}`
): (list: S[]) => S[];
...
...

import { path } from './path.js'
import { sortBy } from './sortBy.js'

export function sortByPath(sortPath) {
  return list => sortBy(path(sortPath))(list)
}

import { sortByPath } from './sortByPath.js'

const list = [{ a: { b: 3 } }, { a: { b: 1 } }, { a: { b: 2 } }]
const sorted = [{ a: { b: 1 } }, { a: { b: 2 } }, { a: { b: 3 } }]

test('with string as path', () => {
  expect(sortByPath('a.b')(list)).toEqual(sorted)
})

test('with list of strings as path', () => {
  expect(sortByPath(['a', 'b'])(list)).toEqual(sorted)
})

test('when path is not found in any item', () => {
	const list = [{ a: { b: 3 } }, { a: { b: 1 } }, { a: {} }]
	expect(sortByPath('a.b.c.d')(list)).toEqual(list)
})

import { pipe, sortByPath } from 'rambda'

const input= [{ a: { b: 2 } }, { a: { b: 1 } }]

describe('R.sortByPath', () => {
  it('with string as path', () => {
    const result = pipe(input, sortByPath('a.b'))
		result[0].a.b // $ExpectType number
  })
  it('with list of strings as path', () => {
    const result = pipe(input, sortByPath(['a', 'b']))
		result[0].a.b // $ExpectType number
  })
	it('with non-existent path', () => {
		// @ts-expect-error
		pipe(input, sortByPath(['a', 'c']))
		// @ts-expect-error
		pipe(input, sortByPath('a.c'))
	})
})

sortByPathDescending<S, K0 extends string & keyof S>(
  path: [K0]
): (list: S[]) => S[];
sortByPathDescending<S, K0 extends string & keyof S>(
  path: `${K0}`
): (list: S[]) => S[];
sortByPathDescending<S, K0 extends string & keyof S, K1 extends string & keyof S[K0]>(
  path: [K0, K1]
): (list: S[]) => S[];
sortByPathDescending<S, K0 extends string & keyof S, K1 extends string & keyof S[K0]>(
  path: `${K0}.${K1}`
): (list: S[]) => S[];
...
...

import { path } from './path.js'
import { sortByDescending } from './sortByDescending.js'

export function sortByPathDescending(sortPath) {
  return list => sortByDescending(path(sortPath))(list)
}

import { sortByPathDescending } from './sortByPathDescending.js'

const list = [{ a: { b: 3 } }, { a: { b: 1 } }, { a: { b: 2 } }]
const sorted = [{ a: { b: 3 } }, { a: { b: 2 } }, { a: { b: 1 } }]

test('with string as path', () => {
  expect(sortByPathDescending('a.b')(list)).toEqual(sorted)
})

test('with list of strings as path', () => {
  expect(sortByPathDescending(['a', 'b'])(list)).toEqual(sorted)
})

sortObject<T, K extends string & keyof T>(predicate: (aProp: string, bProp: string, aValue: T[K], bValue: T[K]) => number): (obj: T) => T;
sortObject<T>(predicate: (aProp: string, bProp: string) => number): (obj: T) => T;

import { sort } from './sort.js'

export function sortObject(predicate) {
  return obj => {
    const keys = Object.keys(obj)
    const sortedKeys = sort((a, b) => predicate(a, b, obj[a], obj[b]))(keys)

    const toReturn = {}
    sortedKeys.forEach(singleKey => {
      toReturn[singleKey] = obj[singleKey]
    })

    return toReturn
  }
}

import { sortObject } from './sortObject.js'

const obj = {
  c: 7,
  a: 100,
  b: 1,
  d: 4,
}

test('happy', () => {
  const predicate = (a, b, aValue, bValue) => {
    if (a === 'a') {
      return -1
    }
    if (b === 'a') {
      return 1
    }
    return aValue > bValue ? -1 : 1
  }
  const result = sortObject(predicate)(obj)
  const expected = {
    a: 100,
    c: 7,
    d: 4,
    b: 1,
  }
  expect(result).toEqual(expected)
})

import { sortObject, pipe } from 'rambda'

const obj = {
  c: 1,
  a: 2,
  b: 3,
}

describe('R.sortObject', () => {
  it('predicate with all arguments', () => {
    const result = pipe(
      obj,
      sortObject((propA, propB, valueA, valueB) => {
        propA // $ExpectType string
        propB // $ExpectType string
        valueA // $ExpectType number
        valueB // $ExpectType number
        return propA > propB ? -1 : 1
      }),
    )

    result // $ExpectType { c: number; a: number; b: number; }
  })

  it('predicate with only property arguments', () => {
    const result = pipe(
      obj,
      sortObject((propA, propB) => {
        propA // $ExpectType string
        propB // $ExpectType string
        return propA > propB ? -1 : 1
      }),
    )
    result // $ExpectType { c: number; a: number; b: number; }
  })
})

sortWith<T>(fns: Array<(a: T, b: T) => number>): (list: T[]) => T[];

function sortHelper(a, b, listOfSortingFns) {
  let result = 0
  let i = 0
  while (result === 0 && i < listOfSortingFns.length) {
    result = listOfSortingFns[i](a, b)
    i += 1
  }

  return result
}

export function sortWith(listOfSortingFns) {
  return list => {
    if (Array.isArray(list) === false) {
      return []
    }

    const clone = list.slice()
    clone.sort((a, b) => sortHelper(a, b, listOfSortingFns))

    return clone
  }
}

import { ascend } from './ascend.js'
import { prop } from './prop.js'
import { sortWith } from './sortWith.js'

const albums = [
  {
    artist: 'Rush',
    genre: 'Rock',
    score: 3,
    title: 'A Farewell to Kings',
  },
  {
    artist: 'Dave Brubeck Quartet',
    genre: 'Jazz',
    score: 3,
    title: 'Timeout',
  },
  {
    artist: 'Rush',
    genre: 'Rock',
    score: 5,
    title: 'Fly By Night',
  },
  {
    artist: 'Daniel Barenboim',
    genre: 'Baroque',
    score: 3,
    title: 'Goldberg Variations',
  },
  {
    artist: 'Glenn Gould',
    genre: 'Baroque',
    score: 3,
    title: 'Art of the Fugue',
  },
  {
    artist: 'Leonard Bernstein',
    genre: 'Romantic',
    score: 4,
    title: 'New World Symphony',
  },
  {
    artist: 'Don Byron',
    genre: 'Jazz',
    score: 5,
    title: 'Romance with the Unseen',
  },
  {
    artist: 'Iron Maiden',
    genre: 'Metal',
    score: 2,
    title: 'Somewhere In Time',
  },
  {
    artist: 'Danny Holt',
    genre: 'Modern',
    score: 1,
    title: 'In Times of Desparation',
  },
  {
    artist: 'Various',
    genre: 'Broadway',
    score: 3,
    title: 'Evita',
  },
  {
    artist: 'Nick Drake',
    genre: 'Folk',
    score: 1,
    title: 'Five Leaves Left',
  },
  {
    artist: 'John Eliot Gardiner',
    genre: 'Classical',
    score: 4,
    title: 'The Magic Flute',
  },
]

test('sorts by a simple property of the objects', () => {
  const sortedAlbums = sortWith([ascend(prop('title'))])(albums)
  expect(sortedAlbums).toHaveLength(albums.length)
  expect(sortedAlbums[0].title).toBe('A Farewell to Kings')
  expect(sortedAlbums[11].title).toBe('Timeout')
})

test('sorts by multiple properties of the objects', () => {
  const sortedAlbums = sortWith([ascend(prop('score')), ascend(prop('title'))])(
    albums,
  )
  expect(sortedAlbums).toHaveLength(albums.length)
  expect(sortedAlbums[0].title).toBe('Five Leaves Left')
  expect(sortedAlbums[1].title).toBe('In Times of Desparation')
  expect(sortedAlbums[11].title).toBe('Romance with the Unseen')
})

test('sorts by 3 properties of the objects', () => {
  const sortedAlbums = sortWith([
    ascend(prop('genre')),
    ascend(prop('score')),
    ascend(prop('title')),
  ])(albums)
  expect(sortedAlbums).toHaveLength(albums.length)
  expect(sortedAlbums[0].title).toBe('Art of the Fugue')
  expect(sortedAlbums[1].title).toBe('Goldberg Variations')
  expect(sortedAlbums[11].title).toBe('New World Symphony')
})

test('sorts by multiple properties using ascend and descend', () => {
  const sortedAlbums = sortWith([ascend(prop('score')), ascend(prop('title'))])(
    albums,
  )
  expect(sortedAlbums).toHaveLength(albums.length)
  expect(sortedAlbums[0].title).toBe('Five Leaves Left')
  expect(sortedAlbums[1].title).toBe('In Times of Desparation')
  expect(sortedAlbums[11].title).toBe('Romance with the Unseen')
})

split(separator: string | RegExp): (str: string) => string[];

export function split(separator) {
  return str => str.split(separator)
}

splitEvery<T>(sliceLength: number): (input: T[]) => (T[])[];

export function splitEvery(sliceLength) {
  return list => {
    if (sliceLength < 1) {
      throw new Error('First argument to splitEvery must be a positive integer')
    }

    const willReturn = []
    let counter = 0

    while (counter < list.length) {
      willReturn.push(list.slice(counter, (counter += sliceLength)))
    }

    return willReturn
  }
}

import { splitEvery } from './splitEvery.js'

test('happy', () => {
  expect(splitEvery(3)([1, 2, 3, 4, 5, 6, 7])).toEqual([[1, 2, 3], [4, 5, 6], [7]])
})

import { pipe, splitEvery } from 'rambda'

const list = [1, 2, 3, 4, 5, 6, 7]

describe('R.splitEvery', () => {
  it('happy', () => {
    const result = pipe(list, splitEvery(3))
    result // $ExpectType number[][]
  })
})

sum(list: number[]): number;

export function sum(list){
	return list.reduce((acc, cur) => acc + cur, 0)
}

import { sum } from './sum.js'

test('happy', () => {
  expect(sum([1,2,3])).toEqual(6)
})

switcher<T extends unknown>(valueToMatch: T): Switchem<T>;
switcher<T extends unknown, U extends unknown>(valueToMatch: T): Switchem2<T, U>;

// API_MARKER_END
// ============================================

import { equals } from './equals.js'

const NO_MATCH_FOUND = Symbol ? Symbol('NO_MATCH_FOUND') : undefined

const getMatchingKeyValuePair = (
  cases, testValue, defaultValue
) => {
  let iterationValue

  for (let index = 0; index < cases.length; index++){
    iterationValue = cases[ index ].test(testValue)

    if (iterationValue !== NO_MATCH_FOUND){
      return iterationValue
    }
  }

  return defaultValue
}

const isEqual = (testValue, matchValue) => {
  const willReturn =
    typeof testValue === 'function' ?
      testValue(matchValue) :
      equals(testValue)(matchValue)

  return willReturn
}

const is = (testValue, matchResult = true) => ({
  key  : testValue,
  test : matchValue =>
    isEqual(testValue, matchValue) ? matchResult : NO_MATCH_FOUND,
})

class Switchem{
  constructor(
    defaultValue, cases, willMatch
  ){
    if (cases === undefined && willMatch === undefined){
      this.cases = []
      this.defaultValue = undefined
      this.willMatch = defaultValue
    } else {
      this.cases = cases
      this.defaultValue = defaultValue
      this.willMatch = willMatch
    }

    return this
  }

  default(defaultValue){
    const holder = new Switchem(
      defaultValue, this.cases, this.willMatch
    )

    return holder.match(this.willMatch)
  }

  is(testValue, matchResult){
    return new Switchem(
      this.defaultValue,
      [ ...this.cases, is(testValue, matchResult) ],
      this.willMatch
    )
  }

  match(matchValue){
    return getMatchingKeyValuePair(
      this.cases, matchValue, this.defaultValue
    )
  }
}

export function switcher(input){
  return new Switchem(input)
}

import { switcher } from './switcher.js'
import { tap } from './tap.js'

test('with undefined', () => {
  const result = switcher(undefined)
    .is(x => x === 0, '0')
    .is(x => x === undefined, 'UNDEFINED')
    .default('3')

  expect(result).toBe('UNDEFINED')
})

test('happy', () => {
  const a = true
  const b = false
  const result = switcher([ a, b ])
    .is([ false, false ], '0')
    .is([ false, true ], '1')
    .is([ true, true ], '2')
    .default('3')

  expect(result).toBe('3')
})

test('can compare objects', () => {
  const result = switcher({ a : 1 })
    .is({ a : 1 }, 'it is object')
    .is('baz', 'it is baz')
    .default('it is default')

  expect(result).toBe('it is object')
})

test('options are mixture of functions and values - input match function', () => {
  const fn = switcher('foo').is('bar', 1)
    .is('foo', x => x + 1)
    .default(1000)

  expect(fn(2)).toBe(3)
})

test('options are mixture of functions and values - input match value', () => {
  const result = switcher('bar').is('bar', 1)
    .is('foo', x => x + 1)
    .default(1000)

  expect(result).toBe(1)
})

test('return function if all options are functions', () => {
  const fn = switcher('foo')
		.is('bar', tap)
    .is('foo', x => x + 1)
    .default(9)

  expect(fn(2)).toBe(3)
})

const switchFn = input =>
  switcher(input)
    .is(x => x.length && x.length === 7, 'has length of 7')
    .is('baz', 'it is baz')
    .default('it is default')

test('works with function as condition', () => {
  expect(switchFn([ 0, 1, 2, 3, 4, 5, 6 ])).toBe('has length of 7')
})

test('works with string as condition', () => {
  expect(switchFn('baz')).toBe('it is baz')
})

test('fallback to default input when no matches', () => {
  expect(switchFn(1)).toBe('it is default')
})

import { switcher } from 'rambda'

describe('R.switcher', () => {
  it('no transformation', () => {
    const list = [1, 2, 3]

    const result = switcher(list.length)
      .is(x => x < 2, 4)
      .is(x => x < 4, 6)
      .default(7)

    result // $ExpectType number
  })
  it('with transformation', () => {
    const list = [1, 2, 3]
    type Stage = 'firstStage' | 'secondStage' | 'thirdStage'

    const result = switcher<number, Stage>(list.length)
      .is(x => x < 2, 'firstStage')
      .is(x => x < 4, 'secondStage')
      .default('thirdStage')

    result // $ExpectType Stage
  })
})

symmetricDifference<T>(x: T[]): (y: T[]) => T[];

import { filter } from './filter.js'
import { excludes } from './excludes.js'

export function symmetricDifference(listA) {
	return listB => [
		...filter(excludes(listB))(listA),
		...filter(excludes(listA))(listB),
	]
}

import { symmetricDifference } from './symmetricDifference.js'

test('symmetricDifference', () => {
  const list1 = [1, 2, 3, 4]
  const list2 = [3, 4, 5, 6]
  expect(symmetricDifference(list1)(list2)).toEqual([1, 2, 5, 6])
  expect(symmetricDifference([])([])).toEqual([])
})

test('symmetricDifference with objects', () => {
  const list1 = [{ id: 1 }, { id: 2 }, { id: 3 }, { id: 4 }]
  const list2 = [{ id: 3 }, { id: 4 }, { id: 5 }, { id: 6 }]
  expect(symmetricDifference(list1)(list2)).toEqual([
    { id: 1 },
    { id: 2 },
    { id: 5 },
    { id: 6 },
  ])
})

import { symmetricDifference } from 'rambda'

describe('R.symmetricDifference', () => {
  it('happy', () => {
    const list1 = [{ id: 1 }, { id: 2 }, { id: 3 }, { id: 4 }]
    const list2 = [{ id: 3 }, { id: 4 }, { id: 5 }, { id: 6 }]
    const result = symmetricDifference(list1)(list2)

    result // $ExpectType { id: number; }[]
  })
})

tail<T extends unknown>(input: T): T extends unknown[] ? 
	T['length'] extends 0 ? [] : T['length'] extends 1 ? [] : 
	T extends [any, ...infer U] ? U : T : T extends string ? string : never;

import { drop } from './drop.js'

export function tail(listOrString) {
  return drop(1)(listOrString)
}

import { tail } from './tail.js'

test('tail', () => {
  expect(tail([1, 2, 3])).toEqual([2, 3])
  expect(tail([1, 2])).toEqual([2])
  expect(tail([1])).toEqual([])
  expect(tail([])).toEqual([])

  expect(tail('abc')).toBe('bc')
  expect(tail('ab')).toBe('b')
  expect(tail('a')).toBe('')
  expect(tail('')).toBe('')
})

import { map, pipe, tail } from 'rambda'

describe('R.tail', () => {
  it('with string', () => {
    const result = tail('foo')

    result // $ExpectType string
  })
  it('with list - using const on short array', () => {
    const result = pipe(
      [1] as const,
      map(x => x * 2),
      tail,
    )
    result // $ExpectType []
  })
  it('with list - using const on empty array', () => {
    const result = pipe(
      [] as const,
      map(x => x * 2),
      tail,
    )
    result // $ExpectType []
  })
  it('with list - using const', () => {
    const result = pipe(
      [1, 2, 3] as const,
      map(x => x * 2),
      tail,
    )
    result // $ExpectType [number, number]
  })
  it('with list - mixed types', () => {
    const result = tail(['foo', 'bar', 1, 2, 3])

    result // $ExpectType (string | number)[]
  })
})

take<T>(howMany: number): {
  (input: string): string;
  (input: readonly T[]): T[];
  (input: T[]): T[];
};
...
...

import { baseSlice } from './_internals/baseSlice.js'

export function take(numberOfItems) {
  return input => {
    if (numberOfItems < 0) {
      return input.slice()
    }
    if (typeof input === 'string') {
      return input.slice(0, numberOfItems)
    }

    return baseSlice(input, 0, numberOfItems)
  }
}

import { take } from './take.js'

test('happy', () => {
  const arr = ['foo', 'bar', 'baz']

  expect(take(1)(arr)).toEqual(['foo'])
  expect(arr).toEqual(['foo', 'bar', 'baz'])
  expect(take(2)(['foo', 'bar', 'baz'])).toEqual(['foo', 'bar'])
  expect(take(3)(['foo', 'bar', 'baz'])).toEqual(['foo', 'bar', 'baz'])
  expect(take(4)(['foo', 'bar', 'baz'])).toEqual(['foo', 'bar', 'baz'])
  expect(take(3)('rambda')).toBe('ram')
})

test('with negative index', () => {
  expect(take(-1)([1, 2, 3])).toEqual([1, 2, 3])
  expect(take(Number.NEGATIVE_INFINITY)([1, 2, 3])).toEqual([1, 2, 3])
})

test('with zero index', () => {
  expect(take(0)([1, 2, 3])).toEqual([])
})

takeLast<T>(howMany: number): {
  (input: string): string;
  (input: readonly T[]): T[];
  (input: T[]): T[];
};
...
...

import { baseSlice } from './_internals/baseSlice.js'

export function takeLast(numberOfItems) {
  return input => {
    const len = input.length
    if (numberOfItems < 0) {
      return input.slice()
    }
    let numValue = numberOfItems > len ? len : numberOfItems

    if (typeof input === 'string') {
      return input.slice(len - numValue)
    }

    numValue = len - numValue

    return baseSlice(input, numValue, len)
  }
}

import { takeLast } from './takeLast.js'

test('with arrays', () => {
  expect(takeLast(1)(['foo', 'bar', 'baz'])).toEqual(['baz'])
  expect(takeLast(2)(['foo', 'bar', 'baz'])).toEqual(['bar', 'baz'])
  expect(takeLast(3)(['foo', 'bar', 'baz'])).toEqual(['foo', 'bar', 'baz'])
  expect(takeLast(4)(['foo', 'bar', 'baz'])).toEqual(['foo', 'bar', 'baz'])
  expect(takeLast(10)(['foo', 'bar', 'baz'])).toEqual(['foo', 'bar', 'baz'])
})

test('with strings', () => {
  expect(takeLast(3)('rambda')).toBe('bda')
  expect(takeLast(7)('rambda')).toBe('rambda')
})

test('with negative index', () => {
  expect(takeLast(-1)([1, 2, 3])).toEqual([1, 2, 3])
  expect(takeLast(Number.NEGATIVE_INFINITY)([1, 2, 3])).toEqual([1, 2, 3])
})

takeLastWhile<T>(predicate: (x: T) => boolean): (input: T[]) => T[];
takeLastWhile<T>(predicate: (x: T, index: number) => boolean): (list: T[]) => T[];

export function takeLastWhile(predicate) {
  return input => {
    if (input.length === 0) {
      return input
    }

    const toReturn = []
    let counter = input.length

    while (counter) {
      const item = input[--counter]
      if (!predicate(item)) {
        break
      }
      toReturn.push(item)
    }

    return toReturn.reverse()
  }
}

import { takeLastWhile } from './takeLastWhile.js'

const list = [1, 2, 3, 4]

test('happy', () => {
  const predicate = x => x > 2
  const result = takeLastWhile(predicate)(list)
  expect(result).toEqual([3, 4])
})

test('predicate is always true', () => {
  const predicate = () => true
  const result = takeLastWhile(predicate)(list)
  expect(result).toEqual(list)
})

test('predicate is always false', () => {
  const predicate = () => false
  const result = takeLastWhile(predicate)(list)
  expect(result).toEqual([])
})

takeWhile<T>(predicate: (x: T, index: number) => boolean): (list: T[]) => T[];
takeWhile<T>(predicate: (x: T) => boolean): (input: T[]) => T[];

export function takeWhile(predicate) {
  return iterable => {
    const toReturn = []
    let counter = 0

    while (counter < iterable.length) {
      const item = iterable[counter++]
      if (!predicate(item)) {
        break
      }
      toReturn.push(item)
    }
    return toReturn
  }
}

import { takeWhile } from './takeWhile.js'

const list = [1, 2, 3, 4, 5]

test('happy', () => {
  const result = takeWhile(x => x < 3)(list)
  expect(result).toEqual([1, 2])
})

test('always true', () => {
  const result = takeWhile(x => true)(list)
  expect(result).toEqual(list)
})

test('always false', () => {
  const result = takeWhile(x => 0)(list)
  expect(result).toEqual([])
})

import { pipe, takeWhile } from 'rambda'

const list = [1, 2, 3]

it('R.takeWhile', () => {
  const result = pipe(
    list,
    takeWhile(x => x > 1),
    takeWhile((x, i) => i + x > 1),
  )
  result // $ExpectType number[]
})

tap<T>(fn: (x: T) => void): (input: T) => T;

export function tap(fn) {
  return x => {
    fn(x)

    return x
  }
}

test(regExpression: RegExp): (str: string) => boolean;

export function test(pattern) {
  return str => str.search(pattern) !== -1
}

import { test as testMethod } from './test.js'

test('happy', () => {
  expect(testMethod(/^x/)('xyz')).toBeTruthy()
  expect(testMethod(/^y/)('xyz')).toBeFalsy()
})

import { test } from 'rambda'

const input = 'foo   '
const regex = /foo/

it('R.test', () => {
  const result = test(regex)(input)

  result // $ExpectType boolean
})

transformPropObject<T extends object, K extends keyof T, Value>(
  valueMapper: (value: T[K]) => Value,
  prop: K,
): (data: T) => MergeTypes<Omit<T, K> & { [P in K]: Value }>;

import {  transformPropObject, pipe } from 'rambda'

it('R.transformPropObject', () => {
	const result = pipe(
		{ a: 1, b: 'foo' },
		transformPropObject(x => {
			x // $ExpectType number
			return x > 2
		}, 'a'),
	)

	result // $ExpectType { b: string; a: boolean; }
})

tryCatch<T, U>(
  fn: (input: T) => U,
  fallback: U
): (input: T) => U;

export function tryCatch(fn, fallback) {
  return input => {
    try {
      return fn(input)
    } catch (e) {
      return fallback
    }
  }
}

import { prop } from './prop.js'
import { tryCatch } from './tryCatch.js'

test('happy', () => {
  const fn = () => {
    throw new Error('foo')
  }
  const result = tryCatch(fn, () => true)()
  expect(result).toBeTruthy()
})

test('when fallback is used', () => {
  const fn = x => x.x

  expect(tryCatch(fn, false)(null)).toBeFalsy()
})

test('with json parse', () => {
  const good = () => JSON.parse(JSON.stringify({ a: 1 }))
  const bad = () => JSON.parse('a{a')

  expect(tryCatch(good, 1)()).toEqual({ a: 1 })
  expect(tryCatch(bad, 1)()).toBe(1)
})

test('when fn is used', () => {
  const fn = prop('x')

  expect(tryCatch(fn, false)({})).toBeUndefined()
  expect(tryCatch(fn, false)({ x: 1 })).toBe(1)
})

import { map, pipe, tryCatch } from 'rambda'

describe('R.tryCatch', () => {
  it('happy', () => {
    const result = pipe(
      ['{a:1', '{"b": 2}'],
      map(
        tryCatch(x => {
          return JSON.parse(x) as string
        }, null),
      ),
    )

    result // $ExpectType (string | null)[]
  })
})

type(x: any): RambdaTypes;

export function type(input) {
  if (input === null) {
    return 'Null'
  }
  if (input === undefined) {
    return 'Undefined'
  }
  if (Number.isNaN(input)) {
    return 'NaN'
  }
  const typeResult = Object.prototype.toString.call(input).slice(8, -1)
  return typeResult === 'AsyncFunction' ? 'Promise' : typeResult
}

import { type as typeRamda } from 'ramda'

import { type } from './type.js'

test('with buffer', () => {
  expect(type(new Buffer.from('foo'))).toBe('Uint8Array')
})

test('with array buffer', () => {
  expect(type(new ArrayBuffer(8))).toBe('ArrayBuffer')
})

test('with big int', () => {
  expect(type(BigInt(9007199254740991))).toBe('BigInt')
})

test('with generators', () => {
  function* generator() {
    yield 1
    yield 2
    yield 3
  }

  const gen = generator()
  expect(type(generator)).toBe('GeneratorFunction')
  expect(type(gen)).toBe('Generator')
})

test('with Date', () => {
  const date = new Date('December 17, 1995 03:24:00')
  expect(type(date)).toBe('Date')
})

test('with infinity', () => {
  expect(type(Number.POSITIVE_INFINITY)).toBe('Number')
})

test('with weak map', () => {
  expect(type(new WeakMap())).toBe('WeakMap')
})

test('with map', () => {
  expect(type(new Map())).toBe('Map')
})

test('with symbol', () => {
  expect(type(Symbol())).toBe('Symbol')
})

test('with simple promise', () => {
  expect(type(Promise.resolve(1))).toBe('Promise')
})

test('with new Boolean', () => {
  expect(type(new Boolean(true))).toBe('Boolean')
})

test('with new String', () => {
  expect(type(new String('I am a String object'))).toBe('String')
})

test('with new Number', () => {
  expect(type(new Number(1))).toBe('Number')
})

test('with error', () => {
  expect(type(Error('foo'))).toBe('Error')
  expect(typeRamda(Error('foo'))).toBe('Error')
})

test('with error - wrong @types/ramda test', () => {
  // @types/ramda expect the result to be 'Error' but it is not
  class ExtendedError extends Error {}
  expect(type(ExtendedError)).toBe('Function')
  expect(typeRamda(ExtendedError)).toBe('Function')
})

test('with new promise', () => {
  const delay = ms =>
    new Promise(resolve => {
      setTimeout(() => {
        resolve(ms + 110)
      }, ms)
    })

  expect(type(delay(10))).toBe('Promise')
})

test('async function', () => {
  expect(type(async () => {})).toBe('Promise')
})

test('async arrow', () => {
  const asyncArrow = async () => {}
  expect(type(asyncArrow)).toBe('Promise')
})

test('function', () => {
  const fn1 = () => {}
  const fn2 = () => {}

  function fn3() {}
  ;[() => {}, fn1, fn2, fn3].map(val => {
    expect(type(val)).toBe('Function')
  })
})

test('object', () => {
  expect(type({})).toBe('Object')
})

test('number', () => {
  expect(type(1)).toBe('Number')
})

test('boolean', () => {
  expect(type(false)).toBe('Boolean')
})

test('string', () => {
  expect(type('foo')).toBe('String')
})

test('null', () => {
  expect(type(null)).toBe('Null')
})

test('array', () => {
  expect(type([])).toBe('Array')
  expect(type([1, 2, 3])).toBe('Array')
})

test('regex', () => {
  expect(type(/\s/g)).toBe('RegExp')
})

test('undefined', () => {
  expect(type(undefined)).toBe('Undefined')
})

test('not a number', () => {
  expect(type(Number('s'))).toBe('NaN')
})

test('set', () => {
  const exampleSet = new Set([1, 2, 3])
  expect(type(exampleSet)).toBe('Set')
  expect(typeRamda(exampleSet)).toBe('Set')
})

test('function inside object 1', () => {
  const obj = {
    f() {
      return 4
    },
  }

  expect(type(obj.f)).toBe('Function')
  expect(typeRamda(obj.f)).toBe('Function')
})

test('function inside object 2', () => {
  const name = 'f'
  const obj = {
    [name]() {
      return 4
    },
  }
  expect(type(obj.f)).toBe('Function')
  expect(typeRamda(obj.f)).toBe('Function')
})

import { type } from 'rambda'

describe('R.type', () => {
  it('happy', () => {
    const result = type(4)

    result // $ExpectType RambdaTypes
  })
})

union<T>(x: T[]): (y: T[]) => T[];

import { excludes } from './excludes.js'

export function union(listA) {
  return listB => [
		...listA,
		...listB.filter(excludes(listA)),
	]
}

import { union } from './union.js'

test('happy', () => {
  expect(union([1, 2])([2, 3])).toEqual([1, 2, 3])
})

test('with list of objects', () => {
  const list1 = [{ a: 1 }, { a: 2 }]
  const list2 = [{ a: 2 }, { a: 3 }]
  const result = union(list1)(list2)
  expect(result).toEqual([{ a: 1 }, { a: 2 }, { a: 3 }])
})

import { union } from 'rambda'

describe('R.union', () => {
  it('happy', () => {
    const result = union([1, 2])([2, 3])

    result // $ExpectType number[]
  })
  it('with array of objects - case 1', () => {
    const list1 = [{ a: 1 }, { a: 2 }]
    const list2 = [{ a: 2 }, { a: 3 }]
    const result = union(list1)(list2)
    result // $ExpectType { a: number; }[]
  })
  it('with array of objects - case 2', () => {
    const list1 = [{ a: 1, b: 1 }, { a: 2 }]
    const list2 = [{ a: 2 }, { a: 3, b: 3 }]
    const result = union(list1)(list2)
    result[0].a // $ExpectType number
    result[0].b // $ExpectType number | undefined
  })
})

unionWith<T>(predicate: (x: T, y: T) => boolean, x: T[]): (y: T[]) => T[];

export function unionWith(predicate, x) {
  return y => {
    const filtered = y.filter(yInstance => {
			return x.every(xInstance => {
				return !predicate(xInstance, yInstance)
			})
    })

    return [...x, ...filtered]
  }
}

import { unionWith } from './unionWith.js'
import { pipe } from './pipe.js'

test('happy', () => {
	const list1 = [{a: 1, b: 1}, {a: 2, b: 1}]
	const list2 = [{a: 2, b: 2}, {a: 3, b: 2}]
	const result = pipe(
		list2,
		unionWith((x, y) => {
			return x.a === y.a
		}, list1),
	)
	expect(result).toEqual([{a: 1, b: 1}, {a: 2, b: 1}, {a: 3, b: 2}])
})

import { pipe, unionWith } from 'rambda'

describe('R.unionWith', () => {
  it('happy', () => {
		const list = [{a: 1, b: 1}, {a: 2, b: 1}]
    const result = pipe(
			list,
			unionWith((x, y) => {
				x.a // $ExpectType number
				y.b // $ExpectType number
				return x.a === y.a
			}, [{a: 2, b: 2}, {a: 3, b: 2}]),
		)

    result[0].a // $ExpectType number
    result[0].b // $ExpectType number
  })
})

uniq<T>(list: T[]): T[];

import { _Set } from './_internals/set.js'

export function uniq(list) {
  const set = new _Set()
  const willReturn = []
  list.forEach(item => {
    if (set.checkUniqueness(item)) {
      willReturn.push(item)
    }
  })

  return willReturn
}

import { uniq } from './uniq.js'

test('happy', () => {
  const list = [1, 2, 3, 3, 3, 1, 2, 0]
  expect(uniq(list)).toEqual([1, 2, 3, 0])
})

test('with object', () => {
  const list = [{ a: 1 }, { a: 2 }, { a: 1 }, { a: 2 }]
  expect(uniq(list)).toEqual([{ a: 1 }, { a: 2 }])
})

test('with nested array', () => {
  expect(uniq([[42], [42]])).toEqual([[42]])
})

test('with booleans', () => {
  expect(uniq([[false], [false], [true]])).toEqual([[false], [true]])
})

test('with falsy values', () => {
  expect(uniq([undefined, null])).toEqual([undefined, null])
})

test('can distinct between string and number', () => {
  expect(uniq([1, '1'])).toEqual([1, '1'])
})

import { uniq } from 'rambda'

describe('R.uniq', () => {
  it('happy', () => {
    const result = uniq([1, 2, 3, 3, 3, 1, 2, 0])
    result // $ExpectType number[]
  })
})

uniqBy<T, U>(fn: (x: T) => U): (list: T[]) => T[];

import { _Set } from '../src/_internals/set.js'

export function uniqBy(fn) {
  return list => {
    const set = new _Set()

    return list.filter(item => set.checkUniqueness(fn(item)))
  }
}

import { uniqBy } from './uniqBy.js'

test('happy', () => {
  expect(uniqBy(Math.abs)([-2, -1, 0, 1, 2])).toEqual([-2, -1, 0])
})

test('returns an empty array for an empty array', () => {
  expect(uniqBy(Math.abs)([])).toEqual([])
})

test('uses R.uniq', () => {
  const list = [{ a: 1 }, { a: 2 }, { a: 1 }]
  const expected = [{ a: 1 }, { a: 2 }]
  expect(uniqBy(x => x)(list)).toEqual(expected)
})

import { uniqBy } from 'rambda'

describe('R.uniqBy', () => {
  it('happy', () => {
    const result = uniqBy(Math.abs)([-2, -1, 0])

    result // $ExpectType number[]
  })
})

uniqWith<T>(predicate: (x: T, y: T) => boolean): (list: T[]) => T[];

function includesWith(predicate, target, list) {
  let willReturn = false
  let index = -1

  while (++index < list.length && !willReturn) {
    const value = list[index]

    if (predicate(target, value)) {
      willReturn = true
    }
  }

  return willReturn
}

export function uniqWith(predicate) {
  return list => {
    let index = -1
    const willReturn = []

    while (++index < list.length) {
      const value = list[index]

      if (!includesWith(predicate, value, willReturn)) {
        willReturn.push(value)
      }
    }

    return willReturn
  }
}

import { uniqWith } from './uniqWith.js'

const list = [{ a: 1 }, { a: 1 }]

test('happy', () => {
  const fn = (x, y) => x.a === y.a

  const result = uniqWith(fn)(list)
  expect(result).toEqual([{ a: 1 }])
})

test('with list of strings', () => {
  const fn = (x, y) => x.length === y.length
  const list = ['0', '11', '222', '33', '4', '55']
  const result = uniqWith(fn)(list)
  expect(result).toEqual(['0', '11', '222'])
})

test('should return items that are not equal to themselves', () => {
  // test case based on https://github.com/remeda/remeda/issues/999
  const data = [
    { id: 1, reason: 'No name' },
    { id: 1, reason: 'No name' },
    { reason: 'No name' },
    { reason: 'No name' },
  ]
  const expectedResult = [
    { id: 1, reason: 'No name' },
    { reason: 'No name' },
    { reason: 'No name' },
  ]

  const result = uniqWith((errorA, errorB) => {
    // the objects with no ids should effectively be ignored from removal of duplicates
    if (errorA.id === undefined || errorB.id === undefined) {
      return false
    }
    return errorA.id === errorB.id
  })(data)

  expect(result).toEqual(expectedResult)
})

import { pipe, uniqWith } from 'rambda'

describe('R.uniqWith', () => {
  it('happy', () => {
    const result = pipe(
      [{ a: 1 }, { a: 1 }],
      uniqWith((x, y) => x.a === y.a),
    )
    result // $ExpectType { a: number; }[]
  })
})

unless<T, U>(predicate: (x: T) => boolean, whenFalseFn: (x: T) => U): (x: T) => T | U;
unless<T>(predicate: (x: T) => boolean, whenFalseFn: (x: T) => T): (x: T) => T;

export function unless(predicate, whenFalseFn) {
  return input => {
    if (predicate(input)) {
      return input
    }

    return whenFalseFn(input)
  }
}

import { unless } from './unless.js'

test('happy', () => {
  expect(
    unless(
      x => x > 10,
      x => x + 1,
    )(20),
  ).toEqual(20)
  expect(
    unless(
      x => x > 10,
      x => x + 1,
    )(5),
  ).toEqual(6)
})

import { pipe, unless } from 'rambda'

const inc = (x: number) => x + 1

describe('R.unless', () => {
  it('happy', () => {
    const result = pipe(
      1,
      unless(x => x > 5, inc),
    )
    result // $ExpectType number
  })
  it('with two different types', () => {
    const result = pipe(
      1,
      unless(
        x => {
          x // $ExpectType number
          return x > 5
        },
        x => {
          x // $ExpectType number
          return `${x}-foo`
        },
      ),
    )
    result // $ExpectType string | number
  })
})

unwind<S extends string>(prop: S): <T extends Record<S, readonly any[]>>(obj: T) => Array<MergeTypes<Omit<T, S> & { [K in S]: T[S][number] }>>;

export function unwind(property) {
  return obj => {
    return obj[property].map(x => ({
      ...obj,
      [property]: x,
    }))
  }
}

import { unwind } from './unwind.js'

test('happy', () => {
  const obj = {
    a: 1,
    b: [2, 3],
    c: [3, 4],
  }
  const expected = [
    {
      a: 1,
      b: 2,
      c: [3, 4],
    },
    {
      a: 1,
      b: 3,
      c: [3, 4],
    },
  ]
  const result = unwind('b')(obj)
  expect(result).toEqual(expected)
})

import { pipe, unwind } from 'rambda'

const obj = {
  a: 1,
  b: [2, 3],
}

describe('R.unwind', () => {
  it('happy', () => {
    const [result] = unwind('b')(obj)
    result.a // $ExpectType number
    result.b // $ExpectType number
  })
  it('inside pipe', () => {
    const [result] = pipe(obj, unwind('b'))
    result.a // $ExpectType number
    result.b // $ExpectType number
  })
})

update<T>(index: number, newValue: T): (list: T[]) => T[];

import { cloneList } from './_internals/cloneList.js'

export function update(index, newValue) {
  return list => {
    const clone = cloneList(list)
    if (index === -1) {
      return clone.fill(newValue, index)
    }

    return clone.fill(newValue, index, index + 1)
  }
}

import { update } from './update.js'

const list = [1, 2, 3]

test('happy', () => {
  const newValue = 8
  const index = 1
  const result = update(index, newValue)(list)

  const expected = [1, 8, 3]
  expect(result).toEqual(expected)
})

test('list has no such index', () => {
  const newValue = 8
  const index = 10
  const result = update(index, newValue)(list)

  expect(result).toEqual(list)
})

test('with negative index', () => {
  expect(update(-1, 10)([1])).toEqual([10])
  expect(update(-1, 10)([])).toEqual([])
  expect(update(-1, 10)(list)).toEqual([1, 2, 10])
  expect(update(-2, 10)(list)).toEqual([1, 10, 3])
  expect(update(-3, 10)(list)).toEqual([10, 2, 3])
})

when<T, U extends T>(predicate: (x: T) => x is U, whenTrueFn: (x: U) => T): (input: T) => T;
when<T>(predicate: (x: T) => boolean, whenTrueFn: (x: T) => T): (input: T) => T;
when<T, U>(predicate: (x: T) => boolean, whenTrueFn: (x: T) => U): (input: T) => T | U;

export function when(predicate, whenTrueFn) {
  return input => {
    if (!predicate(input)) {
      return input
    }

    return whenTrueFn(input)
  }
}

import { when } from './when.js'

const predicate = x => typeof x === 'number'

test('happy', () => {
  const fn = when(predicate, x => x + 1)
  expect(fn(11)).toBe(12)
  expect(fn('foo')).toBe('foo')
})

import { head, pipe, tap, when } from 'rambda'

function notNull<T>(a: T | null | undefined): a is T {
  return a != null
}

describe('R.when', () => {
  it('happy', () => {
    const result = pipe(
      1,
      when(
        x => x > 2,
        x => x,
      ),
      tap(x => {
        x // $ExpectType number
      }),
      when(
        x => x > 2,
        x => String(x),
      ),
    )

    result // $ExpectType string | number
  })

	it('with assertion of type', () => {
    const result = pipe(
      [1, null, 2, 3],
      head,
      when(notNull, x => x + 1),
    )
    result // $ExpectType number | null
  })
})

zip<K>(x: K[]): <V>(y: V[]) => KeyValuePair<K, V>[];

export function zip(left) {
  return right => {
    const result = []
    const length = Math.min(left.length, right.length)

    for (let i = 0; i < length; i++) {
      result[i] = [left[i], right[i]]
    }

    return result
  }
}

import { zip } from './zip.js'

const array1 = [1, 2, 3]
const array2 = ['A', 'B', 'C']

test('should return an array', () => {
  const actual = zip(array1)(array2)
  expect(actual).toBeInstanceOf(Array)
})

test('should return and array or tuples', () => {
  const expected = [
    [1, 'A'],
    [2, 'B'],
    [3, 'C'],
  ]
  const actual = zip(array1)(array2)
  expect(actual).toEqual(expected)
})

test('should truncate result to length of shorted input list', () => {
  const expectedA = [
    [1, 'A'],
    [2, 'B'],
  ]
  const actualA = zip([1, 2])(array2)
  expect(actualA).toEqual(expectedA)

  const expectedB = [
    [1, 'A'],
    [2, 'B'],
  ]
  const actualB = zip(array1)(['A', 'B'])
  expect(actualB).toEqual(expectedB)
})

import { zip } from 'rambda'

describe('R.zip', () => {
  it('happy', () => {
    const array1 = [1, 2, 3]
    const array2 = ['A', 'B', 'C']
    let a: Partial<any>
    const result = zip(array1)(array2)
    result[0][0] // $ExpectType number
    result[0][1] // $ExpectType string
  })
})

zipWith<T, U, TResult>(
  fn: (x: T, y: U) => TResult,
  list1: readonly T[],
): (list2: readonly U[]) => TResult[];

import { take } from './take.js'

export function zipWith(fn, x) {
  return y =>
    take(x.length > y.length ? y.length : x.length)(x).map((xInstance, i) =>
      fn(xInstance, y[i]),
    )
}

import { zipWith } from './zipWith.js'

const add = (x, y) => x + y
const list1 = [1, 2, 3]
const list2 = [10, 20, 30, 40]
const list3 = [100, 200]

test('when second list is shorter', () => {
  const result = zipWith(add, list1)(list3)
  expect(result).toEqual([101, 202])
})

test('when second list is longer', () => {
  const result = zipWith(add, list1)(list2)
  expect(result).toEqual([11, 22, 33])
})

import { pipe, zipWith } from 'rambda'

const list1 = [1, 2]
const list2 = [10, 20, 30]

describe('R.zipWith', () => {
  it('happy', () => {
    const result = pipe(
      list2,
      zipWith((x, y) => {
        x // $ExpectType number
        y // $ExpectType number
        return `${x}-${y}`
      }, list1),
    )

    result // $ExpectType string[]
  })
})