check

name	check
description	Run the full code quality pipeline (TypeScript + Biome + Knip), fix all issues, and clean up comments in changed code.

This skill is the central entry point for fixing any CI/CD or pre-commit hook failures. Invoke this skill whenever a build or validation step fails.

The user wants to verify and fix all code quality issues in the project.

What the pipeline checks

npm run check runs three tools in parallel via run-p:

1. tsc --noEmit — TypeScript type checking
2. biome check --write — Linting + formatting with auto-fix
3. knip --production — Unused exports, files, and dependencies

Pre-commit hook (lefthook) runs the same pipeline automatically on every commit.

Running the check

npm run check

To run tools individually for targeted diagnosis:

npm run ts:check      # TypeScript only
npm run lint:fix      # Biome with auto-fix
npm run knip          # Knip unused code analysis

Fixing common errors

TypeScript errors

Missing type on Prisma-generated code:

• If errors reference src/@generated/prisma, run npm run db:gen first — the client may be stale

declare keyword on GraphQL InputType fields: The project uses declare to re-declare Zod DTO fields with GraphQL decorators (see profile-update.input.ts):

@InputType()
export class MyInput extends MyZodDto {
  @Field(() => String, { nullable: true })
  declare myField?: string;
}

See the /add-graphql-type skill for full details on integrating Zod with GraphQL InputTypes.

Import path errors:

• Always use @/ alias for internal imports (maps to src/)
• Never use relative ../../ paths that cross module boundaries

Biome errors

Biome auto-fixes most issues with --write. Common remaining issues:

• Unused variables: prefix with _ (e.g. _unusedParam) or remove them
• Explicit any: use unknown and narrow the type, or add // biome-ignore lint/suspicious/noExplicitAny: <reason>
• Missing return types: add explicit return type to exported functions

Knip errors

Knip flags exports that are not imported anywhere in production code (--production excludes test files).

Common false positives to investigate:

• NestJS module classes exported from *.module.ts — these ARE used via app.module.ts imports array
• GraphQL types decorated with @ObjectType() / @InputType() — used by NestJS reflection at runtime
• Enum types used only in GraphQL schema

When Knip flags something legitimately unused:

• Remove the export if it's truly dead code
• If it's a public API for external consumers, verify the import chain
• DEFENSIVE DELETION RULE: NEVER delete classes decorated with @Injectable, @Resolver, @Controller, @ObjectType, @InputType, or @Module just because Knip flagged them. If one of these is flagged, it usually means you forgot to register it in its parent *.module.ts or app.module.ts. Fix the DI wiring instead of deleting the code. Delete code ONLY if it is a truly obsolete helper function or dead logic.

Comment cleanup

After fixing tool errors, review all changed/created code for comment quality:

1. Remove unnecessary comments — commented-out dead code, obvious statements (e.g. // call the function), outdated TODOs
2. Ensure remaining comments are in English — translate or rewrite any non-English comment; if it adds no real value, remove it instead

Workflow

1. Run npm run check and capture the full output
2. Report what was found (errors by tool + comment issues)
3. Fix TypeScript errors first (they often cascade)
4. Biome fixes are mostly automatic — review the diff
5. For Knip warnings, investigate each flagged export before removing
6. Clean up comments in changed/created files
7. Re-run npm run check until clean

Fallback Strategy (Circuit Breaker)

CRITICAL: Do not enter an infinite loop of fixing. If you attempt to fix a check error and the EXACT SAME error persists after 3 attempts, STOP.

1. Undo the specific change that caused the unresolvable error.
2. Stop the workflow.
3. Explain the underlying issue to the user and ask for human guidance.