lodash/test/isSet.spec.ts

import assert from 'node:assert';
import lodashStable from 'lodash';
import { set, falsey, stubFalse, args, slice, symbol, weakSet, realm } from './utils';
import isSet from '../src/isSet';

describe('isSet', () => {
    it('should return `true` for sets', () => {
        if (Set) {
            assert.strictEqual(isSet(set), true);
        }
    });

    it('should return `false` for non-sets', () => {
        const expected = lodashStable.map(falsey, stubFalse);

        const actual = lodashStable.map(falsey, (value, index) => (index ? isSet(value) : isSet()));

        assert.deepStrictEqual(actual, expected);

        assert.strictEqual(isSet(args), false);
        assert.strictEqual(isSet([1, 2, 3]), false);
        assert.strictEqual(isSet(true), false);
        assert.strictEqual(isSet(new Date()), false);
        assert.strictEqual(isSet(new Error()), false);
        assert.strictEqual(isSet(slice), false);
        assert.strictEqual(isSet({ a: 1 }), false);
        assert.strictEqual(isSet(1), false);
        assert.strictEqual(isSet(/x/), false);
        assert.strictEqual(isSet('a'), false);
        assert.strictEqual(isSet(symbol), false);
        assert.strictEqual(isSet(weakSet), false);
    });

    it('should work for objects with a non-function `constructor` (test in IE 11)', () => {
        const values = [false, true],
            expected = lodashStable.map(values, stubFalse);

        const actual = lodashStable.map(values, (value) => isSet({ constructor: value }));

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

    it('should work with weak sets from another realm', () => {
        if (realm.set) {
            assert.strictEqual(isSet(realm.set), true);
        }
    });
});