test_runner: use AsyncLocalStorage instead of async_hooks

[mcollina]

Track the test that owns the current async context with an AsyncLocalStorage instead of a createHook() init/destroy map, so node:test no longer installs async hooks (including promise hooks) for every run.

Test#runInAsyncScope() enters the test's context directly rather than wrapping AsyncResource#runInAsyncScope(), to avoid adding frames to user stack traces. The snapshot changes drop one <node-internal-frames> line, since that frame now lives in the test runner and is filtered out.

Refs: #61030

---

AI generated, reviewed by me

[nodejs-github-bot]

Review requested:

• @nodejs/test_runner

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.49%. Comparing base (8ae0ad0) to head (1f16984).
⚠️ Report is 8 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #66795      +/-   ##
==========================================
- Coverage   90.52%   90.49%   -0.03%     
==========================================
  Files         797      797              
  Lines      278220   278225       +5     
  Branches    53456    53458       +2     
==========================================
- Hits       251857   251793      -64     
- Misses      16751    16810      +59     
- Partials     9612     9622      +10     

Files with missing lines	Coverage Δ
lib/internal/test_runner/harness.js	87.32% <100.00%> (-0.81%)	⬇️
lib/internal/test_runner/test.js	97.97% <100.00%> (+0.03%)	⬆️
lib/internal/test_runner/utils.js	66.30% <100.00%> (+0.13%)	⬆️

... and 37 files with indirect coverage changes

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[atlowChemi]

LGTM, but let's also see bench affects

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/78472/

[mcollina]

Benchmark results for benchmark/test_runner, comparing this PR (ef8d21b) against its parent (9df97a7). I used 30 runs per binary on an 8-core Linux machine with no CPU pinning.

Every benchmark that creates many tests is faster, and the gain grows with the number of tests:

Benchmark	Change
suite-tests (all 24 configs)	+16% to +70% ***
test-options (all 9 options)	+40% to +44% ***
hooks (all 4 hook types)	+40% to +43% ***
test-only	+40.5% ***
global-concurrent-tests	+29% to +46% ***
run-single-test-file, isolation=none	+10% / +15% *** (10 / 100 files)
run-single-test-file, isolation=process	+2% to +3%
mock-timers scheduler.wait	+59% ***
test-reporters, mock-fn, global-sequential-tests	flat

mock-timers mode='setTimeout' shows -17% (**), but its accuracy band is ±12–22%. The PR doesn't touch mock timers, and the neighboring setImmediate/setInterval rows are flat, so I read it as noise.

Full output

                                                                                                    confidence improvement accuracy (*)    (**)   (***)
test_runner/global-concurrent-tests.js type='async' n=100                                                  ***     29.50 %       ±4.92%  ±6.55%  ±8.54%
test_runner/global-concurrent-tests.js type='async' n=1000                                                 ***     36.30 %       ±2.03%  ±2.70%  ±3.52%
test_runner/global-concurrent-tests.js type='async' n=10000                                                ***     46.40 %       ±1.09%  ±1.46%  ±1.91%
test_runner/global-concurrent-tests.js type='sync' n=100                                                   ***     29.50 %       ±4.52%  ±6.04%  ±7.92%
test_runner/global-concurrent-tests.js type='sync' n=1000                                                  ***     34.64 %       ±1.75%  ±2.33%  ±3.03%
test_runner/global-concurrent-tests.js type='sync' n=10000                                                 ***     43.89 %       ±1.21%  ±1.62%  ±2.11%
test_runner/global-sequential-tests.js type='async' n=100                                                           1.43 %       ±5.40%  ±7.19%  ±9.37%
test_runner/global-sequential-tests.js type='async' n=1000                                                        -21.64 %      ±27.16% ±36.13% ±47.03%
test_runner/global-sequential-tests.js type='async' n=10000                                                        -3.14 %       ±7.34%  ±9.80% ±12.85%
test_runner/global-sequential-tests.js type='sync' n=100                                                            4.88 %       ±5.62%  ±7.49%  ±9.78%
test_runner/global-sequential-tests.js type='sync' n=1000                                                          -4.82 %      ±26.65% ±35.46% ±46.15%
test_runner/global-sequential-tests.js type='sync' n=10000                                                          0.27 %       ±6.80%  ±9.04% ±11.77%
test_runner/hooks.js hook='after' n=1000                                                                   ***     42.29 %       ±1.89%  ±2.52%  ±3.28%
test_runner/hooks.js hook='afterEach' n=1000                                                               ***     39.96 %       ±1.57%  ±2.08%  ±2.72%
test_runner/hooks.js hook='before' n=1000                                                                  ***     40.97 %       ±1.68%  ±2.25%  ±2.95%
test_runner/hooks.js hook='beforeEach' n=1000                                                              ***     43.30 %       ±1.38%  ±1.84%  ±2.39%
test_runner/mock-fn.js mode='define' n=1000000                                                                      0.69 %       ±0.97%  ±1.29%  ±1.68%
test_runner/mock-fn.js mode='execute' n=1000000                                                            ***      2.39 %       ±0.82%  ±1.09%  ±1.43%
test_runner/mock-timers.js mode='AbortSignal.timeout' n=1000                                                        0.32 %       ±5.21%  ±6.94%  ±9.03%
test_runner/mock-timers.js mode='Date' n=1000                                                               **      8.16 %       ±5.87%  ±7.82% ±10.17%
test_runner/mock-timers.js mode='enable-AbortSignal.timeout' n=1000                                          *      7.26 %       ±5.76%  ±7.67% ±10.00%
test_runner/mock-timers.js mode='enable-all' n=1000                                                          *     -2.29 %       ±2.09%  ±2.78%  ±3.62%
test_runner/mock-timers.js mode='enable-Date' n=1000                                                                1.43 %       ±3.65%  ±4.85%  ±6.32%
test_runner/mock-timers.js mode='enable-default' n=1000                                                            -0.57 %       ±2.30%  ±3.07%  ±4.00%
test_runner/mock-timers.js mode='enable-empty-apis' n=1000                                                          0.57 %       ±7.23%  ±9.62% ±12.52%
test_runner/mock-timers.js mode='enable-scheduler.wait' n=1000                                                     -6.64 %       ±6.73%  ±8.95% ±11.65%
test_runner/mock-timers.js mode='enable-setImmediate' n=1000                                                        0.93 %       ±6.33%  ±8.42% ±10.96%
test_runner/mock-timers.js mode='enable-setInterval' n=1000                                                        -1.49 %       ±5.89%  ±7.84% ±10.21%
test_runner/mock-timers.js mode='enable-setTimeout' n=1000                                                   *     -7.29 %       ±5.92%  ±7.87% ±10.24%
test_runner/mock-timers.js mode='runAll' n=1000                                                                     1.65 %       ±7.03%  ±9.36% ±12.21%
test_runner/mock-timers.js mode='scheduler.wait' n=1000                                                    ***     59.11 %       ±9.95% ±13.30% ±17.43%
test_runner/mock-timers.js mode='setImmediate' n=1000                                                              -5.86 %      ±13.10% ±17.43% ±22.68%
test_runner/mock-timers.js mode='setInterval' n=1000                                                                1.54 %       ±4.62%  ±6.15%  ±8.00%
test_runner/mock-timers.js mode='setTime' n=1000                                                                    6.64 %      ±34.95% ±46.51% ±60.54%
test_runner/mock-timers.js mode='setTimeout' n=1000                                                         **    -17.34 %      ±12.49% ±16.64% ±21.71%
test_runner/run-single-test-file.js isolation='none' numberOfTestFiles=1                                            0.05 %       ±7.27%  ±9.68% ±12.60%
test_runner/run-single-test-file.js isolation='none' numberOfTestFiles=10                                  ***      9.90 %       ±4.54%  ±6.04%  ±7.86%
test_runner/run-single-test-file.js isolation='none' numberOfTestFiles=100                                 ***     14.95 %       ±2.11%  ±2.81%  ±3.67%
test_runner/run-single-test-file.js isolation='process' numberOfTestFiles=1                                 **      2.90 %       ±2.11%  ±2.81%  ±3.66%
test_runner/run-single-test-file.js isolation='process' numberOfTestFiles=10                               ***      2.43 %       ±0.49%  ±0.65%  ±0.84%
test_runner/run-single-test-file.js isolation='process' numberOfTestFiles=100                              ***      2.09 %       ±0.17%  ±0.23%  ±0.29%
test_runner/suite-tests.js concurrency='no' testType='async' testsPerSuite=10 numberOfSuites=10            ***     17.17 %       ±2.49%  ±3.32%  ±4.33%
test_runner/suite-tests.js concurrency='no' testType='async' testsPerSuite=10 numberOfSuites=100           ***     32.35 %       ±1.90%  ±2.53%  ±3.30%
test_runner/suite-tests.js concurrency='no' testType='async' testsPerSuite=100 numberOfSuites=10           ***     28.22 %       ±2.18%  ±2.91%  ±3.79%
test_runner/suite-tests.js concurrency='no' testType='async' testsPerSuite=100 numberOfSuites=100          ***     44.18 %       ±1.11%  ±1.47%  ±1.92%
test_runner/suite-tests.js concurrency='no' testType='async' testsPerSuite=1000 numberOfSuites=10          ***     42.72 %       ±1.11%  ±1.48%  ±1.93%
test_runner/suite-tests.js concurrency='no' testType='async' testsPerSuite=1000 numberOfSuites=100         ***     64.60 %       ±1.13%  ±1.51%  ±1.99%
test_runner/suite-tests.js concurrency='no' testType='sync' testsPerSuite=10 numberOfSuites=10             ***     16.68 %       ±1.66%  ±2.21%  ±2.88%
test_runner/suite-tests.js concurrency='no' testType='sync' testsPerSuite=10 numberOfSuites=100            ***     32.94 %       ±1.90%  ±2.53%  ±3.29%
test_runner/suite-tests.js concurrency='no' testType='sync' testsPerSuite=100 numberOfSuites=10            ***     30.97 %       ±1.97%  ±2.63%  ±3.42%
test_runner/suite-tests.js concurrency='no' testType='sync' testsPerSuite=100 numberOfSuites=100           ***     42.32 %       ±1.26%  ±1.68%  ±2.19%
test_runner/suite-tests.js concurrency='no' testType='sync' testsPerSuite=1000 numberOfSuites=10           ***     41.06 %       ±1.23%  ±1.64%  ±2.14%
test_runner/suite-tests.js concurrency='no' testType='sync' testsPerSuite=1000 numberOfSuites=100          ***     64.84 %       ±0.95%  ±1.27%  ±1.66%
test_runner/suite-tests.js concurrency='yes' testType='async' testsPerSuite=10 numberOfSuites=10           ***     18.75 %       ±3.33%  ±4.45%  ±5.83%
test_runner/suite-tests.js concurrency='yes' testType='async' testsPerSuite=10 numberOfSuites=100          ***     30.69 %       ±1.83%  ±2.44%  ±3.17%
test_runner/suite-tests.js concurrency='yes' testType='async' testsPerSuite=100 numberOfSuites=10          ***     28.47 %       ±2.10%  ±2.80%  ±3.65%
test_runner/suite-tests.js concurrency='yes' testType='async' testsPerSuite=100 numberOfSuites=100         ***     40.10 %       ±1.14%  ±1.52%  ±1.99%
test_runner/suite-tests.js concurrency='yes' testType='async' testsPerSuite=1000 numberOfSuites=10         ***     40.18 %       ±0.92%  ±1.23%  ±1.60%
test_runner/suite-tests.js concurrency='yes' testType='async' testsPerSuite=1000 numberOfSuites=100        ***     70.10 %       ±1.34%  ±1.80%  ±2.37%
test_runner/suite-tests.js concurrency='yes' testType='sync' testsPerSuite=10 numberOfSuites=10            ***     16.00 %       ±2.81%  ±3.75%  ±4.89%
test_runner/suite-tests.js concurrency='yes' testType='sync' testsPerSuite=10 numberOfSuites=100           ***     30.93 %       ±1.94%  ±2.58%  ±3.36%
test_runner/suite-tests.js concurrency='yes' testType='sync' testsPerSuite=100 numberOfSuites=10           ***     27.68 %       ±2.06%  ±2.75%  ±3.59%
test_runner/suite-tests.js concurrency='yes' testType='sync' testsPerSuite=100 numberOfSuites=100          ***     41.52 %       ±1.42%  ±1.90%  ±2.49%
test_runner/suite-tests.js concurrency='yes' testType='sync' testsPerSuite=1000 numberOfSuites=10          ***     39.17 %       ±1.06%  ±1.41%  ±1.85%
test_runner/suite-tests.js concurrency='yes' testType='sync' testsPerSuite=1000 numberOfSuites=100         ***     69.22 %       ±1.17%  ±1.57%  ±2.06%
test_runner/test-only.js selected=1 n=10000                                                                ***     40.52 %       ±1.28%  ±1.70%  ±2.23%
test_runner/test-options.js option='none' n=10000                                                          ***     43.96 %       ±1.07%  ±1.42%  ±1.86%
test_runner/test-options.js option='skip-method-with-message' n=10000                                      ***     41.00 %       ±1.34%  ±1.79%  ±2.34%
test_runner/test-options.js option='skip-method' n=10000                                                   ***     39.91 %       ±1.05%  ±1.40%  ±1.83%
test_runner/test-options.js option='skip-with-message' n=10000                                             ***     42.29 %       ±1.27%  ±1.69%  ±2.21%
test_runner/test-options.js option='skip' n=10000                                                          ***     41.89 %       ±1.06%  ±1.41%  ±1.85%
test_runner/test-options.js option='todo-method-with-message' n=10000                                      ***     39.87 %       ±1.08%  ±1.44%  ±1.88%
test_runner/test-options.js option='todo-method' n=10000                                                   ***     39.96 %       ±0.88%  ±1.17%  ±1.53%
test_runner/test-options.js option='todo-with-message' n=10000                                             ***     41.44 %       ±0.93%  ±1.24%  ±1.62%
test_runner/test-options.js option='todo' n=10000                                                          ***     41.92 %       ±1.22%  ±1.63%  ±2.14%
test_runner/test-reporters.js reporter='dot' n=10000                                                               -0.55 %       ±1.16%  ±1.54%  ±2.01%
test_runner/test-reporters.js reporter='junit' n=10000                                                       *      1.08 %       ±0.95%  ±1.27%  ±1.65%
test_runner/test-reporters.js reporter='lcov' n=10000                                                              -0.04 %       ±1.35%  ±1.80%  ±2.34%
test_runner/test-reporters.js reporter='spec' n=10000                                                        *      1.08 %       ±0.93%  ±1.23%  ±1.61%
test_runner/test-reporters.js reporter='tap' n=10000                                                                0.23 %       ±1.35%  ±1.79%  ±2.34%

Be aware that when doing many comparisons the risk of a false-positive
result increases. In this case, there are 80 comparisons, you can thus
expect the following amount of false-positive results:
  4.00 false positives, when considering a   5% risk acceptance (*, **, ***),
  0.80 false positives, when considering a   1% risk acceptance (**, ***),
  0.08 false positives, when considering a 0.1% risk acceptance (***)

[atlowChemi]

@mcollina this might be worth a notable-change PRs with changes that should be highlighted in changelogs.