Just for funzies - you can include all of TJSpec in your codes to get a functioning test framework. DON'T FORGET TO CALL `run()`

tjspec-spec.js

const results = TJSpec.describe('A Suite', (it) => {
    it('passes with no exceptions', () => {
    });

    it('throws an exception when an exception fails', (assert) => {
        try {
            assert.true(false, 'should fail');
        } catch (e) {
            return assert.true(true);
        }
        assert.true(false, 'should never reach this');
    });

    it('asserts when two things are equal', (assert) => {
        try {
            return assert.equals(2 + 2, 4);
        } catch (e) {
            return assert.true(false);
        }
        assert.true(false, 'should never reach this');
    });

    it('continues when something fails', (assert) => {
        const results = TJSpec.describe('inner test', (it) => {
            it('throws, but continues', () => {
                throw new Error('OH NOES!');
            });
            it('runs', () => {
                assert.true(false);
            });
        }).run();
        assert.equals(results.length, 2);
        assert.equals(results[0].error, 'OH NOES!');
        assert.equals(results[1].error, 'Expected: false to be true');
    });
}).run();
console.log(results);

tjspec.js

const TJSpec = {
    _suites: [],
    describe: function (desc, suite) {
        const _currentSuite = {
            desc,
            specs: [],
            assert: this.assert,
            run: function () {
                return this.specs.map(spec => spec.spec());
            }
        };
        suite(this.it.bind(_currentSuite));
        this._suites.push(_currentSuite);
        return _currentSuite;
    },
    it: function (desc, spec) {
        this.specs.push({
            desc, 
            spec: () => {
                try {
                    spec(this.assert);
                } catch (e) {
                    return { desc, error: e.message, passed: false };
                }
                return { desc, passed: true };
            }
        });
    },
    assert: {
        true: (actual) => { if (actual !== true) throw new Error(`Expected: ${actual} to be true`) },
        equals: (actual, expected) => { if (actual != expected) throw new Error(`Expected: ${actual} to == ${expected}`) },
    },
    run: function () {
        return this._suites.map(suite => suite.run());
    },
}