feat: add file path to xunit reporter

[bmish]

Description of the Change

Expose test file path for each test case in the xunit reporter.

<testsuite name="Mocha Tests" tests="2" failures="0" errors="0" skipped="0" timestamp="Tue, 17 May 2022 21:10:34 GMT" time="0.001">
<testcase classname="Array #indexOf()" name="should return -1 when the value is not present" file="/path/to/test/array.js" time="0"/>
<testcase classname="Set #has()" name="should return false when the value is not present" file="/path/to/test/set.js" time="0"/>
</testsuite>

Alternate Designs

Why should this be in core?

The test file path was already added to other reporters in this PR:

• Exposing filename in JSON, doc, and json-stream reporters #4219

It seems the file path can be added to each reporter as needed.

Benefits

• Can be easier to find test file from file path instead of just test name, especially when overlapping/similar/identical test names are present, or in a large codebase
• In particular, it can be easier for automated tooling to find the test file from the file path as opposed to the test name when performing test analysis or other scripting

Possible Drawbacks

• Greater size / noise of output for people who don't need the file path
• Let me know if there's any other reason not to do this

Applicable issues

None.

This should be part of a minor release as an enhancement.

I submitted this last year as #4885 but heard no response. I am recreating the same PR now after hearing interest in it in this comment: #4885 (comment)

Fixes #5112.

[github-actions]

This PR hasn't had any recent activity, and I'm labeling it stale. Remove the label or comment or this PR will be closed in 14 days. Thanks for contributing to Mocha!

[villelahdenvuo]

I would like to see this merged, ideally with the Cypress fix I mentioned above...

[JoshuaKGoldberg]

LGTM, thanks for pressing on this! 🙌

I think we can merge & consider any extra support for Cypress as a followup to discuss separately (is Cypress doing something odd, even wrong?).

[voxpelli]

Included in v10.4.0 🎉

[SophieDel]

Hi,
I am having trouble with the "file" field with the plugin xunit (laster version 3.1.4, dated from 2 months) in Jenkins. I didn't have find any solutions yet, and I stay in 10.3 for now for that reason. Am I missing anything...?
Thank you !

[JoshuaKGoldberg]

@SophieDel "having trouble" isn't enough details to go off of. Please file a new issue if you think this is a bug or missing feature in Mocha, or if not, see the Mocha Discord for asking for help in its #help channel. 🤎

[SophieDel]

@JoshuaKGoldberg thank you ! I will explore further, and file a new issue if needed :)