this.timeout fails inside describe block

[James Fox]

Opening new issue as requested:

• **I'm submitting a ... **

  • bug report

• What is the current behavior?
  Context not enforced inside describe blocks
  this is incorrect

• What is the expected behavior?

• What is the motivation / use case for changing the behavior?
  this.timeout(<ms>) does not work

• Please tell us about your environment:

• version: 2.0.0-beta.X
• Browser: [Chrome 57]
• Language: [all]

We commonly call this.timeout inside the beginning of the root describe in a test file:

describe('some_module/some_component', function() {
  this.timeout(10000);

  // Setup and run some tests
  ...
});

Here is an example output:

➜  myapp git:(karma_parallel) grunt test:myapp:unit
Running "test:myapp:unit" (test) task

Running "karma:myapp:unit" (karma) task

START:
Hash: e0bdc8cc97632b01d813
Version: webpack 2.4.1
Time: 44ms
webpack: Compiled successfully.
webpack: Compiling...
Hash: e0fab60a728ee52c6d84
Version: webpack 2.4.1
Time: 21798ms
                     Asset     Size  Chunks                    Chunk Names
               0.bundle.js   273 kB       0  [emitted]  [big]  extras_bundle
               1.bundle.js   110 kB       1  [emitted]         stub_data_bundle
             firstparty.js  6.97 MB       2  [emitted]  [big]  firstparty
src/js/tests/myapp/main.js  1.79 MB       3  [emitted]  [big]  src/js/tests/myapp/main.js
                 vendor.js  8.22 MB       4  [emitted]  [big]  vendor

webpack: Compiled with warnings.
Chrome 63.0.3239 (Mac OS X 10.12.6) ERROR
  Uncaught TypeError: this.timeout is not a function
  at src/js/tests/myapp/main.js:287
Chrome 63.0.3239 (Mac OS X 10.12.6) ERROR
  Uncaught TypeError: this.timeout is not a function
  at src/js/tests/myapp/main.js:356

Finished in 2.413 secs / 0 secs

SUMMARY:
✔ 0 tests completed
Warning: Task "karma:myapp:unit" failed. Use --force to continue.

Aborted due to warnings.

And the relevant portion of the karma config:

  frameworks: ['parallel', 'mocha-debug', 'mocha'],

    parallelOptions: {
      executors: 2, // Defaults to cpu-count - 1
      shardStrategy: 'round-robin',
    },

[Joel Jeske]

Thank you for this bug report. This is occurring because this framework must call all the describe blocks in every instance, even those that contain it()s that will only be run in another instance. It is difficult and error-prone to fake the entire executing API of this for each describe.

As opposed to mocking the API, it might be easiest to put the this.timeout() in a before() or beforeAll(). Those will only be called in the instances that will actually run each test spec.

Example:

Instead of

describe('some_module/some_component', function() {
  this.timeout(10000);

  // Setup and run some tests
  ...
});

Try this

describe('some_module/some_component', function() {
  before(function() { // Runs once
    this.timeout(10000);
  });

  // Setup and run some tests
  ...
});

[James Fox]

This approach works! I think if this is the only non-standard thing we have to do that I can get onboard with this approach.

I'm hesitant to deviate too much from following the mocha docs, but this exception alone would be worth it.

Coming across another issue that I'll open a separate ticket for.

[SeulGi Choi(Chase)]

For me, this is accessible and set timeout works in the before statement but it's reset in the it statement. As a workaround,

describe("component", () => {
  it("description", function(done) {
    this.timeout(10000); // place the timeout here make it works as expected.
    ...
  });
});

FYI, the code was as follow

describe("component", () => {
  it("description", (done) => {
    ...
  }).timeout(10000); // was set timeout here.
});