lodash/test/invokeMap.spec.ts

import assert from 'node:assert';
import lodashStable from 'lodash';
import { slice, stubOne } from './utils';
import invokeMap from '../src/invokeMap';

describe('invokeMap', () => {
    it('should invoke a methods on each element of `collection`', () => {
        const array = ['a', 'b', 'c'],
            actual = invokeMap(array, 'toUpperCase');

        assert.deepStrictEqual(actual, ['A', 'B', 'C']);
    });

    it('should support invoking with arguments', () => {
        const array = [
                function () {
                    return slice.call(arguments);
                },
            ],
            actual = invokeMap(array, 'call', null, 'a', 'b', 'c');

        assert.deepStrictEqual(actual, [['a', 'b', 'c']]);
    });

    it('should work with a function for `methodName`', () => {
        const array = ['a', 'b', 'c'];

        const actual = invokeMap(
            array,
            function (left, right) {
                return left + this.toUpperCase() + right;
            },
            '(',
            ')',
        );

        assert.deepStrictEqual(actual, ['(A)', '(B)', '(C)']);
    });

    it('should work with an object for `collection`', () => {
        const object = { a: 1, b: 2, c: 3 },
            actual = invokeMap(object, 'toFixed', 1);

        assert.deepStrictEqual(actual, ['1.0', '2.0', '3.0']);
    });

    it('should treat number values for `collection` as empty', () => {
        assert.deepStrictEqual(invokeMap(1), []);
    });

    it('should not error on nullish elements', () => {
        const array = ['a', null, undefined, 'd'];

        try {
            var actual = invokeMap(array, 'toUpperCase');
        } catch (e) {}

        assert.deepStrictEqual(actual, ['A', undefined, undefined, 'D']);
    });

    it('should not error on elements with missing properties', () => {
        const objects = lodashStable.map([null, undefined, stubOne], (value) => ({ a: value }));

        const expected = lodashStable.map(objects, (object) => (object.a ? object.a() : undefined));

        try {
            var actual = invokeMap(objects, 'a');
        } catch (e) {}

        assert.deepStrictEqual(actual, expected);
    });

    it('should invoke deep property methods with the correct `this` binding', () => {
        const object = {
            a: {
                b: function () {
                    return this.c;
                },
                c: 1,
            },
        };

        lodashStable.each(['a.b', ['a', 'b']], (path) => {
            assert.deepStrictEqual(invokeMap([object], path), [1]);
        });
    });

    it('should return a wrapped value when chaining', () => {
        let array = ['a', 'b', 'c'],
            wrapped = _(array),
            actual = wrapped.invokeMap('toUpperCase');

        assert.ok(actual instanceof _);
        assert.deepEqual(actual.valueOf(), ['A', 'B', 'C']);

        actual = wrapped.invokeMap(
            function (left, right) {
                return left + this.toUpperCase() + right;
            },
            '(',
            ')',
        );

        assert.ok(actual instanceof _);
        assert.deepEqual(actual.valueOf(), ['(A)', '(B)', '(C)']);
    });

    it('should support shortcut fusion', () => {
        let count = 0,
            method = function () {
                count++;
                return this.index;
            };

        const array = lodashStable.times(LARGE_ARRAY_SIZE, (index) => ({
            index: index,
            method: method,
        }));

        const actual = _(array).invokeMap('method').take(1).value();

        assert.strictEqual(count, 1);
        assert.deepEqual(actual, [0]);
    });
});