tsc

Find and Fix TypeScript Errors

Use the TypeScript compiler to check for type errors in your codebase.

1. Run Type Check

npx tsc --noEmit

Or using the project's build script:

npm run build:check

2. Review Output

For each error, note:

• File path and line number
• Error code (e.g., TS2339, TS7006)
• Error description

3. Common Type Errors and Fixes

• TS2339 (Property does not exist) -> Add to interface or use type assertion
• TS7006 (Parameter has implicit any) -> Add explicit type annotation
• TS2345 (Argument type mismatch) -> Fix the type or use type guard
• TS2322 (Type not assignable) -> Ensure types are compatible
• TS2531 (Object possibly null) -> Add null check or use optional chaining
• TS2532 (Object possibly undefined) -> Add undefined check
• TS18046 (Unknown type) -> Add type narrowing

4. Fix Iteratively

For each error:

1. Update code to fix the type issue
2. Re-run type check to verify:

   npx tsc --noEmit
   

3. Commit when a file is clean:

   git add <file>
   git commit -m "fix(types): resolve TS<code> in <file>"
   

5. Strict Mode Settings

For stricter checking, ensure tsconfig.json includes:

{
  "compilerOptions": {
    "strict": true,
    "noImplicitAny": true,
    "strictNullChecks": true,
    "noImplicitReturns": true,
    "noUnusedLocals": true,
    "noUnusedParameters": true
  }
}

6. Final Validation

npx tsc --noEmit
npm run build
npm test

Goal: Zero TypeScript errors with strict mode enabled.