lodash/test/after.spec.ts

import assert from 'node:assert';
import lodashStable from 'lodash';
import after from '../src/after';

describe('after', () => {
    function testAfter(n, times) {
        let count = 0;
        lodashStable.times(
            times,
            after(n, () => {
                count++;
            }),
        );
        return count;
    }

    it('should create a function that invokes `func` after `n` calls', () => {
        assert.strictEqual(
            testAfter(5, 5),
            1,
            'after(n) should invoke `func` after being called `n` times',
        );
        assert.strictEqual(
            testAfter(5, 4),
            0,
            'after(n) should not invoke `func` before being called `n` times',
        );
        assert.strictEqual(testAfter(0, 0), 0, 'after(0) should not invoke `func` immediately');
        assert.strictEqual(testAfter(0, 1), 1, 'after(0) should invoke `func` when called once');
    });

    it('should coerce `n` values of `NaN` to `0`', () => {
        assert.strictEqual(testAfter(NaN, 1), 1);
    });

    it('should use `this` binding of function', () => {
        const afterFn = after(1, function () {
                return ++this.count;
            }),
            object = { after: afterFn, count: 0 };

        object.after();
        assert.strictEqual(object.after(), 2);
        assert.strictEqual(object.count, 2);
    });
});