var Given = require('given');
  var expect = require('expect');

  describe("A Given example", function() {
    var given = undefined;

    beforeEach(function() {
      given = Given(this);
      given({
        name:     function() { return "Alice"; }),
        greeting: function() { return "Hello"; }),
        message:  function() {
          return this.greeting + ' ' + this.name + '!';
        });
      });
    }); 

    it("prints the correct message", function() {
      expect(this.message).toEqual("Hello Alice!");
    });

    it("can redefine the greeting", function() {
      given('greeting', function() { return 'Yo'; });
      expect(this.message).toEqual("Yo Alice!");
    });

    it("can redefine the name to be capitalized", function() {
      given('name', function() { return this.name.toUpperCase()'; });
      expect(this.message).toEqual("Yo ALICE!");
    });
  });
          
        

Given.js

Write DRY specs with lazy setup code

Download v1.0.0!

Given.js:

• Is inspired by RSpec's let helper method
• Keeps your spec setup code DRY

  Examples:

  • Testing an Angular.js directive

• Can improve the performance of your tests

  Variables defined using Given.js only spring into existence when referenced, so variables that are not used in every test do not incur a setup cost. This is contrary to a test suite where an entire fixture is constructed in a beforeEach function.

• Is test framework agnostic

  Given.js will work with Mocha, Jasmine, Sinon and just about any other test framework you can think of. If it doesn't, it's a bug.

• Is comprehensivley tested

  Given.js itself is written and maintained in a TDD-style and should be considered of a sufficient quality for production use.

• Produces helpful error messages when things go wrong

  Given.js traps specific errors, for example, cyclic variable definitions and give you a meaningful error message rather than a raw stack overflow error.

  
    given('foo', function() { return "I am " + this.bar; }); 
    given('bar', function() { return "I am " + this.foo; }); 
    this.bar // => "recursive definition of variable 'bar' detected"
            

• Installation:

  Given.js can also be installed using bower (a package manager for frontend components, see bower.io for more details):

  $ bower install given

  or by using npm

  $ npm install given