🐛 Bug: "Cannot find module" if module contains TS error

[sam-super]

Bug Report Checklist

• I have read and agree to Mocha's Code of Conduct and Contributing Guidelines
• I have searched for related issues and issues with the faq label, but none matched my issue.
• I have '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, my usage of Mocha, or Mocha itself.
• I want to provide a PR to resolve this

Expected

When i have TS error in a module included in a test, it should show the TS error

Actual

When there is a TS error it shows "Cannot find module".

Minimal, Reproducible Example

I have what i think is a pretty simple typescript setup but at some point the compilation error handling has started causing a very hard to debug "Cannot find module", error rather than the TS error.

This is a stripped down repo which still exhibits the issue:
https://github.com/sam-super/mocha-ts-node-bug

Versions

mocha@11.7.5
node@v24.11.0

Additional Info

E.g. from the reference example repo:

npm run test -- test/included-module-ts-error.test.ts

Exception during run: Error: Cannot find module '[...]/test/helpers/bad-module' imported from [...]/test/included-module-ts-error.test.ts

Possibly related issue is it manages to execute a test with a TS error in the top-level test file/suite without complaint:

npm run test -- test/top-level-compilation.test.ts

  should error with ts error
    ✔ but passes when it should have failed

[mccmrunal]

can I take this one if anyone else hasn't started working

[mark-wiemer]

@mccmrunal you can always work on any issue, but "status: in triage" bugs are not necessary accepted by maintainers, "status: accepting PRs" are more likely to be reviewed. That said, draft PRs for triaged bugs are always welcome as they can be helpful for triaging issues.