# Testing signals — istanbuljs/nyc

> Canonical page: https://codevetter.com/unpack/nyc/testing-signals

# Testing signals — istanbuljs/nyc

Scanned commit 908620475199fa7b9ea0ea8b21d6d8ad6921e3ae (2026-05-17). Generated by codevetter codevetter 1.15.0 on 2026-10-02.

Source inspection; upstream code and tests were not executed.

Tests and CI were inspected, not executed; test existence establishes intended checks, not passing results. TAP tests combine direct NYC calls, spawned CLI fixtures, and output snapshots. Development tests generally target generated self-coverage copies, with a separate coverage variable and exit writer. Coverage inspection is bounded, and explicit Windows branches and ignored error paths limit what the configured checks establish.
- package.json specifies TAP ^18.7.2 and Standard lint; .taprc disables TAP coverage, excludes helper/fixture paths, sets one job and a 360-second timeout, and preloads self-coverage-helper.js. These settings and CI were inspected only. — [package.json#L6-L16](https://github.com/istanbuljs/nyc/blob/908620475199fa7b9ea0ea8b21d6d8ad6921e3ae/package.json#L6-L16) [package.json#L88-L97](https://github.com/istanbuljs/nyc/blob/908620475199fa7b9ea0ea8b21d6d8ad6921e3ae/package.json#L88-L97) [.taprc#L1-L11](https://github.com/istanbuljs/nyc/blob/908620475199fa7b9ea0ea8b21d6d8ad6921e3ae/.taprc#L1-L11) [.github/workflows/ci.yaml#L22-L35](https://github.com/istanbuljs/nyc/blob/908620475199fa7b9ea0ea8b21d6d8ad6921e3ae/.github/workflows/ci.yaml#L22-L35)
- build-self-coverage.js instruments runtime files into self-coverage using ___NYC_SELF_COVERAGE___; test helper paths resolve the generated CLI, and self-coverage-helper writes that separate global coverage at exit. — [build-self-coverage.js#L9-L22](https://github.com/istanbuljs/nyc/blob/908620475199fa7b9ea0ea8b21d6d8ad6921e3ae/build-self-coverage.js#L9-L22) [build-self-coverage.js#L36-L42](https://github.com/istanbuljs/nyc/blob/908620475199fa7b9ea0ea8b21d6d8ad6921e3ae/build-self-coverage.js#L36-L42) [test/helpers/paths.js#L5-L7](https://github.com/istanbuljs/nyc/blob/908620475199fa7b9ea0ea8b21d6d8ad6921e3ae/test/helpers/paths.js#L5-L7) [self-coverage-helper.js#L14-L36](https://github.com/istanbuljs/nyc/blob/908620475199fa7b9ea0ea8b21d6d8ad6921e3ae/self-coverage-helper.js#L14-L36)
- CLI integration tests define checks for threshold success/failure, failing child status, configuration precedence, argument forwarding, process trees, and both spawn-wrap settings; testSuccess asserts zero status, empty stderr, and a stdout snapshot. — [test/nyc-integration.js#L58-L83](https://github.com/istanbuljs/nyc/blob/908620475199fa7b9ea0ea8b21d6d8ad6921e3ae/test/nyc-integration.js#L58-L83) [test/nyc-integration.js#L110-L151](https://github.com/istanbuljs/nyc/blob/908620475199fa7b9ea0ea8b21d6d8ad6921e3ae/test/nyc-integration.js#L110-L151) [test/nyc-integration.js#L180-L205](https://github.com/istanbuljs/nyc/blob/908620475199fa7b9ea0ea8b21d6d8ad6921e3ae/test/nyc-integration.js#L180-L205) [test/helpers/test-success.js#L5-L13](https://github.com/istanbuljs/nyc/blob/908620475199fa7b9ea0ea8b21d6d8ad6921e3ae/test/helpers/test-success.js#L5-L13)
- test/instrument.js checks mode preservation, complete-copy, include/exclude behavior, explicit in-place operation, outside-root rejection, and deletion guards. — [test/instrument.js#L47-L69](https://github.com/istanbuljs/nyc/blob/908620475199fa7b9ea0ea8b21d6d8ad6921e3ae/test/instrument.js#L47-L69) [test/instrument.js#L90-L109](https://github.com/istanbuljs/nyc/blob/908620475199fa7b9ea0ea8b21d6d8ad6921e3ae/test/instrument.js#L90-L109) [test/instrument.js#L240-L299](https://github.com/istanbuljs/nyc/blob/908620475199fa7b9ea0ea8b21d6d8ad6921e3ae/test/instrument.js#L240-L299) [test/instrument.js#L338-L353](https://github.com/istanbuljs/nyc/blob/908620475199fa7b9ea0ea8b21d6d8ad6921e3ae/test/instrument.js#L338-L353)
- Collection tests assert zero counters for unloaded --all sources and nonzero counters after require(); cache tests run collision and identical-file fixtures and assert child status 0. — [test/add-all-files.js#L18-L53](https://github.com/istanbuljs/nyc/blob/908620475199fa7b9ea0ea8b21d6d8ad6921e3ae/test/add-all-files.js#L18-L53) [test/wrap.js#L96-L111](https://github.com/istanbuljs/nyc/blob/908620475199fa7b9ea0ea8b21d6d8ad6921e3ae/test/wrap.js#L96-L111) [test/cache.js#L16-L34](https://github.com/istanbuljs/nyc/blob/908620475199fa7b9ea0ea8b21d6d8ad6921e3ae/test/cache.js#L16-L34)
- Source-map tests cover external/inline maps, cache-file creation, exclude-after-remap behavior, and --all in a module package; TypeScript tests run committed mapping.js with mapping enabled and disabled, rather than directly testing a TypeScript loader. — [test/nyc-integration.js#L416-L470](https://github.com/istanbuljs/nyc/blob/908620475199fa7b9ea0ea8b21d6d8ad6921e3ae/test/nyc-integration.js#L416-L470) [test/tsc.js#L9-L27](https://github.com/istanbuljs/nyc/blob/908620475199fa7b9ea0ea8b21d6d8ad6921e3ae/test/tsc.js#L9-L27) [test/fixtures/tsc/package.json#L3-L8](https://github.com/istanbuljs/nyc/blob/908620475199fa7b9ea0ea8b21d6d8ad6921e3ae/test/fixtures/tsc/package.json#L3-L8)
- Process tests inspect matching UUID coverage/process files and external-ID indexing; SIGTERM/SIGINT tests return without assertions on Windows, and nyc.config.js disables threshold enforcement there despite configured 100% thresholds. — [test/processinfo.js#L40-L84](https://github.com/istanbuljs/nyc/blob/908620475199fa7b9ea0ea8b21d6d8ad6921e3ae/test/processinfo.js#L40-L84) [test/report.js#L18-L39](https://github.com/istanbuljs/nyc/blob/908620475199fa7b9ea0ea8b21d6d8ad6921e3ae/test/report.js#L18-L39) [nyc.config.js#L16-L21](https://github.com/istanbuljs/nyc/blob/908620475199fa7b9ea0ea8b21d6d8ad6921e3ae/nyc.config.js#L16-L21)
- CI declares npm test on Ubuntu Node 20/24 and Windows lts/*, but suppressEPIPE and several parent-completion error branches are explicitly excluded from instrumentation; no execution results were collected. — [.github/workflows/ci.yaml#L10-L35](https://github.com/istanbuljs/nyc/blob/908620475199fa7b9ea0ea8b21d6d8ad6921e3ae/.github/workflows/ci.yaml#L10-L35) [lib/commands/helpers.js#L53-L59](https://github.com/istanbuljs/nyc/blob/908620475199fa7b9ea0ea8b21d6d8ad6921e3ae/lib/commands/helpers.js#L53-L59) [bin/nyc.js#L123-L127](https://github.com/istanbuljs/nyc/blob/908620475199fa7b9ea0ea8b21d6d8ad6921e3ae/bin/nyc.js#L123-L127)

Every claim links to its cited files at the pinned commit. Citations identify source evidence; they do not establish runtime correctness. Independent CodeVetter scan — not reviewed by upstream maintainers.

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