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{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Test runner's `--test-rerun-failures` could swallow actual failures on retries","articleBody":"### Version\n\n26.1.0\n\n### Platform\n\n```text\nDarwin ARM64\n```\n\n### Subsystem\n\ntest_runner\n\n### What steps will reproduce the bug?\n\nThe following example test file will reproduce the bug:\n\n```javascript\n// Demonstrates that `node --test --test-rerun-failures` can mark a failing test as passing on retry without executing its body.\n// Root cause: the runtime disambiguator at lib/internal/test_runner/test.js:793-801 keys tests purely by `file:line:column`.\n// A `t.test()` registered inside a factory function gets the same source location regardless of which parent invoked the factory.\n// The disambiguator counter is assigned in execution order across the whole run, so on retry - when the set of running tests changes,\n// the surviving failing test inherits a counter slot that, in attempt 0, belonged to a different (passing) sibling.\n// Node matches by that slot, replaces `this.fn` with a synthetic noop replay, and reports the failure as a pass.\n\nimport { describe, it } from 'node:test';\nimport { strict as assert } from 'node:assert';\n\nfunction makeSuite(shouldPass, label) {\n  return async (t) =\u003e {\n    await t.test('inner', async () =\u003e {\n      if (!shouldPass) assert.fail(`${label} should fail`);\n    });\n  };\n}\n\ndescribe('parents', { concurrency: false }, () =\u003e {\n  it('A passes', makeSuite(true,  'A'));\n  it('B fails',  makeSuite(false, 'B'));   // the only real failure\n  it('C passes', makeSuite(true,  'C'));\n});\n```\n\nExecuted with:\n\n```bash\nnode --test --test-rerun-failures=rerun.json repro.mjs   # attempt 0\n# B fails as expected; rerun.json now contains A and C plus their\n# inner subtests keyed as \"repro.mjs:13:13\" and \"repro.mjs:13:13:(1)\"\n\nnode --test --test-rerun-failures=rerun.json repro.mjs   # retry\n# all 6 tests reported as passing, exit code 0\n# B's assert.fail was never executed\n```\n\n### How often does it reproduce? Is there a required condition?\n\nHappens consistently\n\n### What is the expected behavior? Why is that the expected behavior?\n\nThe test `inner` should not be replaced with a `noop` for `B fails`, allowing it to actually execute\n\n### What do you see instead?\n\nThe `inner` test of `B fails` is skipped completely, due to a erroneous disambiguation\n\n### Additional information\n\n_No response_","author":{"url":"https://github.com/atlowChemi","@type":"Person","name":"atlowChemi"},"datePublished":"2026-05-19T09:01:15.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":0},"url":"https://github.com/63424/node/issues/63424"}