import assert from 'node:assert'; import lodashStable from 'lodash'; import { _, args, LARGE_ARRAY_SIZE, stubNaN } from './utils'; describe('intersection methods', () => { lodashStable.each(['intersection', 'intersectionBy', 'intersectionWith'], (methodName) => { const func = _[methodName]; it(`\`_.${methodName}\` should return the intersection of two arrays`, () => { const actual = func([2, 1], [2, 3]); assert.deepStrictEqual(actual, [2]); }); it(`\`_.${methodName}\` should return the intersection of multiple arrays`, () => { const actual = func([2, 1, 2, 3], [3, 4], [3, 2]); assert.deepStrictEqual(actual, [3]); }); it(`\`_.${methodName}\` should return an array of unique values`, () => { const actual = func([1, 1, 3, 2, 2], [5, 2, 2, 1, 4], [2, 1, 1]); assert.deepStrictEqual(actual, [1, 2]); }); it(`\`_.${methodName}\` should work with a single array`, () => { const actual = func([1, 1, 3, 2, 2]); assert.deepStrictEqual(actual, [1, 3, 2]); }); it(`\`_.${methodName}\` should work with \`arguments\` objects`, () => { const array = [0, 1, null, 3], expected = [1, 3]; assert.deepStrictEqual(func(array, args), expected); assert.deepStrictEqual(func(args, array), expected); }); it(`\`_.${methodName}\` should treat \`-0\` as \`0\``, () => { const values = [-0, 0], expected = lodashStable.map(values, lodashStable.constant(['0'])); const actual = lodashStable.map(values, (value) => lodashStable.map(func(values, [value]), lodashStable.toString), ); assert.deepStrictEqual(actual, expected); }); it(`\`_.${methodName}\` should match \`NaN\``, () => { const actual = func([1, NaN, 3], [NaN, 5, NaN]); assert.deepStrictEqual(actual, [NaN]); }); it(`\`_.${methodName}\` should work with large arrays of \`-0\` as \`0\``, () => { const values = [-0, 0], expected = lodashStable.map(values, lodashStable.constant(['0'])); const actual = lodashStable.map(values, (value) => { const largeArray = lodashStable.times( LARGE_ARRAY_SIZE, lodashStable.constant(value), ); return lodashStable.map(func(values, largeArray), lodashStable.toString); }); assert.deepStrictEqual(actual, expected); }); it(`\`_.${methodName}\` should work with large arrays of \`NaN\``, () => { const largeArray = lodashStable.times(LARGE_ARRAY_SIZE, stubNaN); assert.deepStrictEqual(func([1, NaN, 3], largeArray), [NaN]); }); it(`\`_.${methodName}\` should work with large arrays of objects`, () => { const object = {}, largeArray = lodashStable.times(LARGE_ARRAY_SIZE, lodashStable.constant(object)); assert.deepStrictEqual(func([object], largeArray), [object]); assert.deepStrictEqual(func(lodashStable.range(LARGE_ARRAY_SIZE), [1]), [1]); }); it(`\`_.${methodName}\` should treat values that are not arrays or \`arguments\` objects as empty`, () => { const array = [0, 1, null, 3]; assert.deepStrictEqual(func(array, 3, { '0': 1 }, null), []); assert.deepStrictEqual(func(null, array, null, [2, 3]), []); assert.deepStrictEqual(func(array, null, args, null), []); }); it(`\`_.${methodName}\` should return a wrapped value when chaining`, () => { const wrapped = _([1, 3, 2])[methodName]([5, 2, 1, 4]); assert.ok(wrapped instanceof _); assert.deepEqual(wrapped.value(), [1, 2]); }); }); });