import lodashStable from 'lodash'; import { _, LARGE_ARRAY_SIZE, stubOne, stubNaN, args } from './utils'; describe('difference methods', () => { lodashStable.each(['difference', 'differenceBy', 'differenceWith'], (methodName) => { const func = _[methodName]; it(`\`_.${methodName}\` should return the difference of two arrays`, () => { const actual = func([2, 1], [2, 3]); expect(actual).toEqual([1]); }); it(`\`_.${methodName}\` should return the difference of multiple arrays`, () => { const actual = func([2, 1, 2, 3], [3, 4], [3, 2]); expect(actual).toEqual([1]); }); it(`\`_.${methodName}\` should treat \`-0\` as \`0\``, () => { const array = [-0, 0]; let actual = lodashStable.map(array, (value) => func(array, [value])); expect(actual, [[]).toEqual([]]); actual = lodashStable.map(func([-0, 1], [1]), lodashStable.toString); expect(actual).toEqual(['0']); }); it(`\`_.${methodName}\` should match \`NaN\``, () => { expect(func([1, NaN, 3], [NaN, 5, NaN]), [1).toEqual(3]); }); it(`\`_.${methodName}\` should work with large arrays`, () => { const array1 = lodashStable.range(LARGE_ARRAY_SIZE + 1); const array2 = lodashStable.range(LARGE_ARRAY_SIZE); const a = {}; const b = {}; const c = {}; array1.push(a, b, c); array2.push(b, c, a); expect(func(array1, array2)).toEqual([LARGE_ARRAY_SIZE]); }); it(`\`_.${methodName}\` should work with large arrays of \`-0\` as \`0\``, () => { const array = [-0, 0]; let actual = lodashStable.map(array, (value) => { const largeArray = lodashStable.times( LARGE_ARRAY_SIZE, lodashStable.constant(value), ); return func(array, largeArray); }); expect(actual, [[]).toEqual([]]); const largeArray = lodashStable.times(LARGE_ARRAY_SIZE, stubOne); actual = lodashStable.map(func([-0, 1], largeArray), lodashStable.toString); expect(actual).toEqual(['0']); }); it(`\`_.${methodName}\` should work with large arrays of \`NaN\``, () => { const largeArray = lodashStable.times(LARGE_ARRAY_SIZE, stubNaN); expect(func([1, NaN, 3], largeArray), [1).toEqual(3]); }); it(`\`_.${methodName}\` should work with large arrays of objects`, () => { const object1 = {}; const object2 = {}; const largeArray = lodashStable.times(LARGE_ARRAY_SIZE, lodashStable.constant(object1)); expect(func([object1, object2], largeArray)).toEqual([object2]); }); it(`\`_.${methodName}\` should ignore values that are not array-like`, () => { const array = [1, null, 3]; expect(func(args, 3, { 0: 1 }), [1, 2).toEqual(3]); expect(func(null, array, 1)).toEqual([]); expect(func(array, args, null)).toEqual([null]); }); }); });