stryker-mutation-test

name	stryker-mutation-test
description	Builds the npm run test:stryker command for Playwright CT mutation testing in nxtcm-components from natural-language requests. Use when the user asks to run mutation testing, Stryker, mutation score, or test quality on a component, spec, or feature. Does not execute the command — asks the user to run it in a terminal.

Stryker mutation test command builder

Construct the correct npm run test:stryker command from what the user says. Never run it (no Shell, no npm run test:stryker). Give the user a copy-paste command and ask them to run it locally.

Workflow

1. Parse the request — which component(s) or test file(s) did they mean?
2. Resolve paths — map names to repo-relative *.tsx component files (not specs).
3. Add flags — --report, STRYKER_CONCURRENCY when appropriate.
4. Output — one fenced bash block + short notes (runtime, prerequisites).
5. Ask the user to run the command in their terminal and paste results if they want help interpreting them.

Command shape

npm run test:stryker -- [stryker-target flags] <component.tsx> [more-components.tsx ...]

With HTML report:

npm run test:stryker:report -- <component.tsx> [more...]
# same as: npm run test:stryker -- --report <component.tsx> ...

Optional env prefix (parallel workers, default is min(4, max(1, cpuCount - 1))):

STRYKER_CONCURRENCY=2 npm run test:stryker -- <component.tsx>

Resolving what to mutate

Pass the component .tsx file, never the .spec.tsx.

User says	Resolve to
FieldWithAPIErrorAlert	packages/nxtcm-rosa-hcp-wizard/src/components/FieldWithAPIErrorAlert.tsx
FieldWithAPIErrorAlert.spec.tsx	Same component path (strip .spec)
rosa hcp footer / RosaHcpWizardFooter	packages/nxtcm-rosa-hcp-wizard/src/Footer/RosaHcpWizardFooter.tsx
src/components/Foo (any package)	packages/<package>/src/components/Foo/Foo.tsx (confirm file exists)
Ambiguous basename	Search with Glob; if multiple matches, ask the user to pick

All paths must be repo-relative from the monorepo root (include the packages/<package>/ prefix when the component lives in a workspace package, not just src/...).

If the user names a spec or you're unsure of the subject, read the .spec.tsx file and trace the mount target and imports to the co-located *.tsx component.

Prerequisites (mention only if relevant):

• Co-located ComponentName.spec.tsx must exist next to ComponentName.tsx.
• Expect long runs (~minutes per component; scales with mutant count).
• No manual cache clear needed before running.

Flag heuristics

User intent	Add
"HTML report", "open report"	--report or test:stryker:report
"faster", "parallel", "use more cores"	STRYKER_CONCURRENCY=4 (warn about RAM)
"laptop", "slow machine", "while I work"	STRYKER_CONCURRENCY=2
First time / default	no extra flags

Response template

Always end with this pattern:

Run this in your terminal from the repo root:

\`\`\`bash
npm run test:stryker -- packages/nxtcm-rosa-hcp-wizard/src/components/FieldWithAPIErrorAlert.tsx
\`\`\`

**Targets:** `FieldWithAPIErrorAlert.tsx` → `FieldWithAPIErrorAlert.spec.tsx`

**Expect:** several minutes; mutation score and survived mutants print when finished.

Paste the summary here if you want help reading the results.

For multiple components, list each component → spec pair.

Examples

User: "Run mutation testing on FieldWithAPIErrorAlert"

npm run test:stryker -- packages/nxtcm-rosa-hcp-wizard/src/components/FieldWithAPIErrorAlert.tsx

User: "Mutation test the footer and the API error alert with a report"

npm run test:stryker -- --report \
  packages/nxtcm-rosa-hcp-wizard/src/components/FieldWithAPIErrorAlert.tsx \
  packages/nxtcm-rosa-hcp-wizard/src/Footer/RosaHcpWizardFooter.tsx

User: "Re-run stryker on the footer, 2 workers"

STRYKER_CONCURRENCY=2 npm run test:stryker -- \
  packages/nxtcm-rosa-hcp-wizard/src/Footer/RosaHcpWizardFooter.tsx

Hard rules

• Do not execute npm run test:stryker, stryker run, or node scripts/stryker-target.mjs.
• Never pass *.spec.tsx paths as mutation targets (runner expects component files).
• Jest is not supported for mutation testing in this repo — Playwright CT is the supported path.
• If paths cannot be resolved confidently, ask one clarifying question before outputting the command.