jasmine-beforeAll

Tested against Jasmine 1.3.1.

The Jasmine test framework test framework provides beforeEach() and afterEach() hooks (equivalent to RSpec's before(:each) and after(:each)) to allow executing setup and teardown code before executing a test (it(...)). For tests where setup/teardown is an expensive operation (for example populating a database with test data) this can lead to terribly inneficient tests. It can also lead to test design that that encourages you to minimimze the number of it(...) tests which obviates the descriptive benefits of BDD tests. Finally it can lead to bloated testuites that take so long to execute that they aren't run frequently enough...

This script patches Jasmine JS to add support for beforeAll() and afterAll() hooks, (equivalent to RSpec's before(:all) and after(:all)).

Caveats:

• Monkey-patches internal Jasmine methods (jasmine.Spec.prototype.addBeforesAndAftersToQueue, jasmine.Suite.prototype.finish and jasmine.Runner.prototype.finishCallback), so it'll possibly break in future Jasmine releases.
• Not yet tested with Node.
• Not yet tested with async setup/teardown.
• Not yet tested when setup/teardown callback throws.

Why aren't they built in into Jasmin?

Excellent question! I'm not sure what the official reason is, but this Jasmine pull request has a good discussion thread on the need for these hooks. I suspect that this comment might be the justification for not including it in Jasmine. While I agree that using before/afterEach nicely isolates tests from each other, it's simply not pragmatic in many situtations.

Using before/afterAll hooks takes more discipline because you have to be careful to ensure that your test blocks are idempotent. That is, executing a test block shouldn't affect other test blocks that depend on the same before/afterAll setups.

Using in Browser:

Include jasmine-beforeAll after including the main jasmine.js script:

  ...
  <link rel="stylesheet" type="text/css" href="jasmine.css">
  <script type="text/javascript" src="jasmine.js"></script>
  <script type="text/javascript" src="jasmine-beforeAll.js"></script>
  <script type="text/javascript" src="jasmine-html.js"></script>

  <!-- include source files here... -->
  ...

  <!-- include spec files here... -->
  ...

Using in Tests

The beforeAll and afterAll hooks are similar to Jasmine's beforeEach and afterEach hooks, except that they only execute once. Use them for doing (expensive) setup/cleanup operations that can be shared between (idempotent) tests. They can be used at the top-level or nested within test suites (describe() blocks). They are executed in the order they are declared.

When running a test, the beforeAll callbacks it depends are executed (once) before any beforeEach callbacks for the test. Conversely, the afterAll callbacks are executed (once) after any afterEach callbacks for the last test that depends on them.

The before/afterAll callbacks are executed lazily. That is, if you don't execut a test that depends on them, they will not be executed, either.

Example

Running the following spec:

describe("Top", function() {
  beforeEach(function() { console.log("Top Setup"); });
  beforeAll(function() { console.log("Top Before All"); });
  afterAll(function() { console.log("Top Cleanup"); });

  describe("Example 1", function() {
    beforeEach(function() { console.log("Example 1 Before Each"); });
    afterEach(function() { console.log("Example 1 After Each"); });
    beforeAll(function() { console.log("Example 1 Setup"); });
    afterAll(function() { console.log("Example 1 Cleanup"); });

    it("Test 1", function() {
      console.log("Test 1");
    });

    it("Test 2", function() {
      console.log("Test 2");
    });
  }); // Example 1

  describe("Example 2", function() {
    beforeAll(function() { console.log("Example 2 Setup"); });
    afterAll(function() { console.log("Example 2 Cleanup"); });

    it("Test 3", function() {
      console.log("Test 3");
    });

    it("Test 4", function() {
      console.log("Test 4");
    });
  }); // Example 2

});

will genegerate the following console output:

Top Setup
Example 1 Setup
Top Before Each
Example 1 Before Each
Test 1
Example 1 After Each
Top Before Each
Example 1 Before Each
Test 2
Example 1 After Each
Example 1 Cleanup
Example 2 Setup
Test 3
Test 4
Example 2 Cleanup
Top Cleanup

License

MIT