jasmine-underscore

jasmine-underscore provides two extensions for Jasmine JavaScript Testing Framework:

• matchers implicitly defined by object functions in Underscore
• a means to write examples into specs

Installation

Simply grab the jasmine-underscore.js from the latest stable release and include it in your Jasmine's test runner file (or add it to jasmine.yml file if you're using Ruby with jasmine-gem). You'll also need Underscore.

Underscore matchers

Underscore has a number of methods for interrogating state. Any underscore function that is prefixed with 'is' can be used as a matcher:

• toBeEmpty()

  • expect([]).toBeEmpty();

• toBeElement()

  • expect(document.body).toBeElement();

• toBeArray()

  • expect([1]).toBeArray();

• toBeObject()

  • expect({}).toBeObject();

• toBeArguments()

  • expect(arguments).toBeArguments();

• toBeFunction()

  • expect(function () {}).toBeFunction();

• toBeString()

  • expect('foo').toBeString();

• toBeNumber() (NaN === true)

  • expect(2).toBeNumber();

• toBeFinite() (NaN === false)

  • expect(2).toBeFinite();

• toBeBoolean()

  • expect(false).toBeBoolean();

• toBeDate()

  • expect(new Date()).toBeDate();

• toBeRegExp()

  • expect(/foo/).toBeRegExp();

• toBeNaN()

  • expect(NaN).toBeNaN();

• toBeNull()

  • expect(null).toBeNull();

• toBeUndefined()

  • expect(undefined).toBeUndefined();

• toBeCompact()

  • expect([1, 2, 3]).toBeCompact();
  • expect([0, 1, false, 2, '', 3]).not.toBeCompact();

• toBeFlat()

  • expect([1, 2, 3, 4]).toBeFlat();
  • expect([1, [2], [3, [[[4]]]]]).not.toBeFlat();

• toHaveUniqueValues()

  • expect([1, 2, 3, 4]).toHaveUniqueValues();
  • expect([1, 2, 1, 3, 1, 4]).not.toHaveUniqueValues();

• toBeWithout(1, 'a', etc..)

  • expect([2, 3, 4]).toBeWithout(0, 1);
  • expect([1, 2, 1, 3, 1, 4]).not.toBeWithout(0, 1);

• toInclude(1)

  • expect([1, 2, 3, 4]).toInclude(2);

• allToSatisfy

  • expect([2, 4, 6]).allToSatisfy(function (val) { return val%2 == 0; });
  • expect([1, 4, 6]).not.allToSatisfy(function (val) { return val%2 == 0; });

• anyToSatisfy

  • expect([2, 3, 5]).anyToSatisfy(function (val) { return val%2 == 0; });
  • expect([1, 3, 5]).not.anyToSatisfy(function (val) { return val%2 == 0; });

Using examples

Underscore is great for generating examples for specs:

_([
    [1, 2, 3], 
    [2, 3, 5]
  ]).each(function (vals) {
  
  var first = vals[0];
  var second = vals[1];
  var total = vals[2];

  it('should sum ' + first + ' and ' + second, function () {
      expect(sum(first, second)).toEqual(total);
  });
});

However, this is quite noisy. The using keyword can be used to reduce this noise, as shown.

using([1, 2, 3], [2, 3, 5], function (first, second, total) {
  it('should sum ' + first + ' and ' + second, function () {
      expect(sum(first, second)).toEqual(total);
  });
});