moy-fp/test/Relation/intersection.test.js

A functional programming library.

import __ from '../../src/Function/__'
/**
 * [a] -> [a] -> [a]
 */
import intersection from '../../src/Relation/intersection'

test('intersection(not using __), first empty array', () => {
  expect(
    intersection([])([{a: 1}, {a: 2}, {a: 3}])
  ).toEqual([])
})

test('intersection(not using __), second empty array', () => {
  expect(
    intersection([{a: 1}, {a: 2}, {a: 3}])([])
  ).toEqual([])
})

test('intersection(not using __), no empty array', () => {
  expect(
    intersection([{a: 2}, {a: 4}])([{a: 1}, {a: 2}, {a: 3}])
  ).toEqual([{a: 2}])
})

test('intersection(not using __), no empty array and mix item type', () => {
  expect(
    intersection([false, 2, {a: 2}, [2], {a: 4}])(['false', {a: 1}, '2', {a: 3}, {a: 2}])
  ).toEqual([{a: 2}])
})

test('intersection(using __), no empty array', () => {
  expect(
    intersection(__, [{a: 1}, {a: 2}, {a: 3}])([{a: 2}, {a: 4}])
  ).toEqual([{a: 2}])
})