Multiple .only should run all targeted tests even in a different context

[clemlatz]

Prerequisites

• Checked that your issue hasn't already been filed by cross-referencing issues with the faq label
• Checked next-gen ES issues and syntax problems by using the same environment and/or transpiler configuration without Mocha to ensure it isn't just a feature that actually isn't supported in the environment in question or a bug in your code.
• 'Smoke tested' the code to be tested by running it outside the real test suite to get a better sense of whether the problem is in the code under test, your usage of Mocha, or Mocha itself
• Ensured that there is no discrepancy between the locally and globally installed versions of Mocha. You can find them with: node_modules/.bin/mocha --version(Local) and mocha --version(Global). We recommend that you not install Mocha globally.

Description

Where they are multiple .only in a test, with one of them in a context, while the second one is not, only the one in a context will be run.

describe('#addition', function () {
  context('When a and b are number', function () {
    it.only('should return the addition', async function () {
      // will be run
    });
  });

  it.only('should throw an error', async function () {
    // will not be run 
 });
});

Steps to Reproduce

1. Clone the MVCE repo here : git clone https://github.com/1024pix/mocha-context-only-bug
2. Install dependencies npm install
3. Run tests : ./node_modules/mocha/bin/mocha test.js

Expected behavior:

The two tests should be run.

Actual behavior:

Only the test in context is run, the second seems to be ignored.

Reproduces how often:

100%

Versions

• The output of mocha --version and node_modules/.bin/mocha --version: 9.2.1
• The output of node --version: v14.17.0
• Your operating system
  • name and version: macOS 12.2.1
  • architecture (32 or 64-bit): 64bit
• Your shell (e.g., bash, zsh, PowerShell, cmd): zsh
• Your browser and version (if running browser tests): n/a
• Any third-party Mocha-related modules (and their versions): no
• Any code transpiler (e.g., TypeScript, CoffeeScript, Babel) being used (and its version): no

Additional Information

n/a

[JoshuaKGoldberg]

Note that per https://mochajs.org/#bdd, context is an alias for describe. This also happens if the code uses describe.

cc @mochajs/maintenance-crew - I think this is a straightforward bug, but a breaking change to fix. So maybe something to save for the next major version... do you think that's too cautious?

[JoshuaKGoldberg]

Many months without input - let's go with a 👍