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