jasmine/suites-and-specs.html.md

layout	title
default	Jasmine Suites & Specs

Specs

Each spec is, naturally, a JavaScript function. You tell Jasmine about a spec with a call to it() with a description string and the function. The string is a description of a behavior that you want your production code to exhibit; it should be meaningful to you when reading a report.

it('should increment a variable', function () {
  var foo = 0;
  foo++;
});

Expectations

Within your spec you will express expectations about the behavior of your application code. This is done using the expect() function and any of various expectation matchers, like this:

it('should increment a variable', function () {
  var foo = 0;            // set up the world
  foo++;                  // call your application code

  expect(foo).toEqual(1); // passes because foo == 1
});

Results of the expectations will be reported to you when the spec is run.

Suites

Specs are grouped in Suites. Suites are defined using the global describe() function:

describe('Calculator', function () {
  it('can add a number', function () {
    ...
  });

  it('has multiply some numbers', function () {
    ...
  });
});

The Suite name is typically the name of a class or other applicaton component, and will be reported with results when your specs are run.

Suites are executed in the order in which describe() calls are made, usually in the order in which their script files are included. Additionally, specs within a suite share a functional scope. So you may declare variables inside a describe block and they are accessible from within your specs. For example:

describe('Calculator', function () {
  var counter = 0

  it('can add a number', function () {
    counter = counter + 2;   // counter was 0 before
    expect(bar).toEqual(2);
  });

  it('can multiply a number', function () {
    counter = counter * 5;   // counter was 2 before
    expect(bar).toEqual(10);
  });
});

Be aware that code directly inside the describe() function is only executed once, which is why counter in the above example is not reset to 0 for the second spec. If you want to initialize variables before each spec, use a beforeEach() function.

Nested Describes

Jasmine supports nested describes. An example:

describe('some suite', function () {

  var suiteWideFoo;

  beforeEach(function () {
    suiteWideFoo = 0;
  });

  describe('some nested suite', function() {
    var nestedSuiteBar;
    beforeEach(function() {
      nestedSuiteBar=1;
    });

    it('nested expectation', function () {
      expect(suiteWideFoo).toEqual(0);
      expect(nestedSuiteBar).toEqual(1);
    });

  });

  it('top-level describe', function () {
    expect(suiteWideFoo).toEqual(0);
    expect(nestedSuiteBar).toEqual(undefined);
  });
});

Disabling Tests & Suites

Specs may be disabled by calling xit() instead of it(). Suites may be disabled by calling xdescribe() instead of describe().