test_runner: add exports option to mock.module

[Han5991]

Summary

• add mock.module(..., { exports }) and normalize option shapes through a shared exports path
• keep defaultExport and namedExports as aliases, and emit runtime DeprecationWarning when legacy options are used
• update docs, tests, and output fixtures/snapshots to reflect deprecation signaling and the new preferred option shape

Legacy Option Mixing Behavior

• Mixed usage of options.exports with legacy options is currently allowed.
• Values are normalized/merged into the same internal exports structure.
• Legacy options are deprecated, but still supported for compatibility during migration.

Scope

• This PR is intentionally scoped to Step 2 of the mock.module: consolidate defaultExport + namedExports into exports #58443 plan.
• Userland migration tooling and legacy option removal are deferred to follow-up work.

Testing

• make lint-js
• python3 tools/test.py test/parallel/test-runner-module-mocking.js
• python3 tools/test.py test/test-runner/test-output-coverage-with-mock.mjs test/test-runner/test-output-typescript-coverage.mjs

Refs: #58443

[nodejs-github-bot]

Review requested:

• @nodejs/test_runner

[JakobJingleheimer]

Related: #58443

(I haven't read through this PR yet though)

[Han5991]

Related: #58443

(I haven't read through this PR yet though)

@JakobJingleheimer

I was working on it with that in mind.
I'm planning to proceed only up to Step 2 of the plan. Is that okay?

[JakobJingleheimer]

Yes, sounds good go me!

It would be ideal (but not required or anything) to land this with a userland migration ready to go. I think it could be done fairly easily.

Cc @Ceres6 this should make your Jest → node:test migration easier 🙂

[Han5991]

Thanks for the feedback. I will scope this PR to Step 2 of the plan: introduce options.exports, keep defaultExport/namedExports as aliases (with deprecation signaling), and defer userland migration + removal to follow-up work.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 89.73%. Comparing base (0777dcc) to head (0498de3).

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #61727      +/-   ##
==========================================
- Coverage   89.73%   89.73%   -0.01%     
==========================================
  Files         675      675              
  Lines      204525   204608      +83     
  Branches    39310    39330      +20     
==========================================
+ Hits       183529   183596      +67     
+ Misses      13287    13286       -1     
- Partials     7709     7726      +17     

Files with missing lines	Coverage Δ
lib/internal/test_runner/mock/mock.js	98.83% <100.00%> (+0.10%)	⬆️

... and 27 files with indirect coverage changes

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