JasmineJS-afterEach

JasmineJS is a popular behavior-driven development (BDD) testing framework for JavaScript. One of its key features is the afterEach() method, which allows developers to execute cleanup code after each test in a test suite.

What is afterEach() in JasmineJS?

The afterEach() method is a JasmineJS hook that is executed after each spec (test) in a describe block. It is particularly useful for resetting state or cleaning up resources after each test.

Here is an example of using afterEach() in JasmineJS:

describe('My object', function() {
  let obj;

  beforeEach(function() {
    obj = { foo: 'bar' };
  });

  afterEach(function() {
    obj = null;
  });

  it('should have a foo property', function() {
    expect(obj.foo).toBeDefined();
  });

  it('should set the foo property to "baz"', function() {
    obj.foo = 'baz';
    expect(obj.foo).toEqual('baz');
  });
});

In this example, we have a test suite that defines an object and sets its foo property to 'bar' in the beforeEach() hook. We then have two tests that check the value of the foo property and set it to 'baz', respectively.

In the afterEach() hook, we reset the value of the obj variable to null to ensure that the object is cleaned up properly after each test.

Why use afterEach() in JasmineJS?

There are several reasons why you might want to use afterEach() in JasmineJS:

1. Cleanup resources: If your tests use external resources, such as a database or file system, afterEach() can be used to clean up those resources after each test.
2. Reset state: If your tests modify state, afterEach() can be used to reset that state to a known value before the next test is executed.
3. Improve test isolation: Ensuring that tests are independent of each other is important for reliable and maintainable tests. Using afterEach() to reset state and clean up resources can help improve test isolation.

Conclusion

The afterEach() method in JasmineJS is a powerful tool for cleaning up resources, resetting state, and improving test isolation. By using this hook in your test suites, you can ensure that each test is executed in a clean and predictable environment.