lodash/test/xor-methods.spec.ts

import assert from 'node:assert';
import lodashStable from 'lodash';
import { _, args, LARGE_ARRAY_SIZE } from './utils';

describe('xor methods', () => {
    lodashStable.each(['xor', 'xorBy', 'xorWith'], (methodName) => {
        const func = _[methodName];

        it(`\`_.${methodName}\` should return the symmetric difference of two arrays`, () => {
            const actual = func([2, 1], [2, 3]);
            assert.deepStrictEqual(actual, [1, 3]);
        });

        it(`\`_.${methodName}\` should return the symmetric difference of multiple arrays`, () => {
            let actual = func([2, 1], [2, 3], [3, 4]);
            assert.deepStrictEqual(actual, [1, 4]);

            actual = func([1, 2], [2, 1], [1, 2]);
            assert.deepStrictEqual(actual, []);
        });

        it(`\`_.${methodName}\` should return an empty array when comparing the same array`, () => {
            const array = [1],
                actual = func(array, array, array);

            assert.deepStrictEqual(actual, []);
        });

        it(`\`_.${methodName}\` should return an array of unique values`, () => {
            let actual = func([1, 1, 2, 5], [2, 2, 3, 5], [3, 4, 5, 5]);
            assert.deepStrictEqual(actual, [1, 4]);

            actual = func([1, 1]);
            assert.deepStrictEqual(actual, [1]);
        });

        it(`\`_.${methodName}\` should return a new array when a single array is given`, () => {
            const array = [1];
            assert.notStrictEqual(func(array), array);
        });

        it(`\`_.${methodName}\` should ignore individual secondary arguments`, () => {
            const array = [0];
            assert.deepStrictEqual(func(array, 3, null, { '0': 1 }), array);
        });

        it(`\`_.${methodName}\` should ignore values that are not arrays or \`arguments\` objects`, () => {
            const array = [1, 2];
            assert.deepStrictEqual(func(array, 3, { '0': 1 }, null), array);
            assert.deepStrictEqual(func(null, array, null, [2, 3]), [1, 3]);
            assert.deepStrictEqual(func(array, null, args, null), [3]);
        });

        it(`\`_.${methodName}\` should return a wrapped value when chaining`, () => {
            const wrapped = _([1, 2, 3])[methodName]([5, 2, 1, 4]);
            assert.ok(wrapped instanceof _);
        });

        it(`\`_.${methodName}\` should work when in a lazy sequence before \`head\` or \`last\``, () => {
            const array = lodashStable.range(LARGE_ARRAY_SIZE + 1),
                wrapped = _(array)
                    .slice(1)
                    [methodName]([LARGE_ARRAY_SIZE, LARGE_ARRAY_SIZE + 1]);

            const actual = lodashStable.map(['head', 'last'], (methodName) =>
                wrapped[methodName](),
            );

            assert.deepEqual(actual, [1, LARGE_ARRAY_SIZE + 1]);
        });
    });
});