@arrows/array/src/filter.test.ts

Functional tools for JS arrays

import { filter } from "./index"

describe("Array filter", () => {
  it("provides functional wrapper for Array.prototype.filter", () => {
    const arr = [1, 2, 3]
    const filteringFn = (x) => x === 1

    const result = filter(filteringFn, arr)
    const result2 = filter(filteringFn)(arr)

    const expected = arr.filter(filteringFn)

    expect(result).toEqual(result2)
    expect(result).toEqual(expected)
  })
})