test_runner: ignore erased TS lines in coverage

[mcollina]

• ignore TypeScript lines that are erased before runtime when source-map coverage is reported
• use the internal TypeScript stripper to detect type-only lines in mapped sources
• add a regression test for import type coverage with --enable-source-maps

Fixes: #54753

[nodejs-github-bot]

Review requested:

• @nodejs/loaders
• @nodejs/test_runner

[codecov]

Codecov Report

❌ Patch coverage is 14.10256% with 67 lines in your changes missing coverage. Please review.
✅ Project coverage is 90.11%. Comparing base (8d3245e) to head (afed6fc).
⚠️ Report is 32 commits behind head on main.

Files with missing lines	Patch %	Lines
lib/internal/test_runner/coverage.js	12.50%	63 Missing ⚠️
lib/internal/modules/typescript.js	33.33%	4 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #63510      +/-   ##
==========================================
- Coverage   90.14%   90.11%   -0.04%     
==========================================
  Files         718      718              
  Lines      227984   228059      +75     
  Branches    42835    42832       -3     
==========================================
- Hits       205522   205520       -2     
- Misses      14235    14318      +83     
+ Partials     8227     8221       -6     

Files with missing lines	Coverage Δ
lib/internal/modules/typescript.js	90.65% <33.33%> (-1.66%)	⬇️
lib/internal/test_runner/coverage.js	59.58% <12.50%> (-4.61%)	⬇️

... and 49 files with indirect coverage changes

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[atlowChemi]

@mcollina what would be the performance price of this change?

[mcollina]

I have no idea tbh, do we have any bench for coverage? I'm mostly focusing on correctness/getting coverage out of experimental.

[atlowChemi]

I have no idea tbh, do we have any bench for coverage? I'm mostly focusing on correctness/getting coverage out of experimental.

I recalled @avivkeller added one, but I can't find one, so I guess we don't 🤷🏽‍♂️

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/73668/

[trivikr]

The merge conflict in debian12-x64 CI is reported in nodejs/build#4345

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/73694/