Minimal JS test DSL

minispec.js

function describe(label, testFunction) {
  return new test(label, testFunction);
}

function test(label, testFunction) {
  var self = this;
  self.testLabel = label;
  self.itLabel;
  var label  = function() { return self.testLabel + ' ' + self.itLabel; };
  var passed = function() { console.log(label(), true); };
  var failed = function(result, expected) {
    console.error(label(), 'Expected:', expected, 'but was', result);
  };

  self.it = function(label, itFunction) {
    self.itLabel = label;
    return itFunction(self.assert);
  };

  self.assert = function(result, expected) {
    if (result === expected) {
      passed();
    } else {
      failed(result, expected);
    }
  };

  testFunction(self.it);
}

minispec.spec.js

describe('describe', function(it) {
  var emptyFunction = function() {};
  var itFunction = function(it) {
    it('it label', emptyFunction);
  };
  var assertFunction = function(it) {
    it('', function(assert) {
      assert(true, true);
    })
  };

  it('has a label', function(assert) {
    var label = 'a label';
    var result = describe(label, emptyFunction)
    assert(result.testLabel, label);
  });

  describe('it', function(it) {
    it('has a label', function(assert) {
      var result = describe('', itFunction);
      assert(result.itLabel, 'it label');
    });
  });

  describe('assert', function(it) {
    it('should have assert function', function(assert) {
      var result = describe('label', itFunction);
      assert(result.assert instanceof Function, true);
    });
  });
});

minispec_example.js

describe('test', function(it) {
  it('can assert true', function(assert) {
    assert(true, true);
  });

  it('should really NOT work', function(assert) {
    assert(false, true);
  });
  
  describe('nested describes', function(it) {
    it('should work again', function(assert) {
      assert(true, true);
    });
  });
});