fix: make it().timeout() work again

[alexander-fenster]

Requirements

• Filling out the template is required. Any pull request that does not include enough information to be reviewed in a timely manner may be closed at the maintainers' discretion.
• All new code requires tests to ensure against regressions.

Description of the Change

Fixes #4598. The code change in #4574 had a breaking change: constructs like it(...).timeout(...), it(...).retries(...), etc. stopped working.

Replacing exports.it = context.it || context.test; with

exports.it = function(...args) {
  (currentContext.it || currentContext.test).apply(this, args);
};

changes the return value of it() to undefined, thus introducing a breaking change in the patch release.

This PR brings this functionality back, and adds an integration test.

Alternate Designs

None. This is a breaking change in a patch release. The behavior, albeit undocumented officially, is widely used (see this StackOverflow answer, for example).

Why should this be in core?

Just bringing back the old behavior.

Benefits

No breaking change :)

Possible Drawbacks

None that I'm aware of.

Applicable issues

#4598

[coveralls]

Coverage remained the same at 94.155% when pulling 080699f on alexander-fenster:it-timeout into c6f874f on mochajs:master.

[giltayar]

LGTM. We should have thought to proxy the return value too in the PR that provoked this fix...

[juergba]

@giltayar #4574 did break it() without requireing or importing it. Could you explain to me, please?

[juergba]

@giltayar #4574 did break it() without requireing or importing it. Could you explain to me, please?

No sorry, I'm wrong. But then your test doesn't prove that your fix is working, @alexander-fenster.

[alexander-fenster]

@juergba Oops, you're right. I updated the test fixture to do const {describe, it} = require('../../../index.js'); and verified it fails without added returns and passes with them.

[juergba]

@alexander-fenster thanks for this PR.

I would prefer putting the tests to a different location.
We already have some tests for our require interface (from #4574):

• test/integration/common-js-require.spec.js
• test/integration/fixtures/common-js-require.fixture.js

Please just append a timeout and retries test to our existing tests. Thank you.

[alexander-fenster]

@juergba Done, please take a look.

[juergba]

@alexander-fenster thank you.
The cancelled browser test is off-topic.