Error Recovery Skill

Comprehensive strategies for diagnosing, fixing, and preventing errors.

Error Classification

Compile-Time Errors

Code Type Common Cause

TS2322 Type mismatch Wrong type assigned

TS2345 Argument type Wrong parameter type

TS2339 Property missing Typo or missing interface property

TS2304 Not found Missing import or declaration

TS2307 Module not found Wrong path or missing package

TS7006 Implicit any Missing type annotation

TS2531 Possibly null Missing null check

Runtime Errors

Error Description Common Fix

ReferenceError Variable not defined Check declaration, scope

TypeError Wrong type operation Add null check, fix type

RangeError Value out of range Validate input range

SyntaxError Invalid syntax Check JSON, string format

Build Errors

Error Description Fix

Module not found Package missing npm install

Out of memory Heap limit Increase NODE_OPTIONS

Config error Invalid config Check tsconfig, vite.config

Test Failures

Type Cause Fix

Assertion Logic error Fix implementation or expectation

Timeout Async issue Add await, increase timeout

Mock error Wrong mock setup Fix mock configuration

Recovery Strategies

Strategy 1: Auto-Fix (Lint/Format)

ESLint auto-fix

npx eslint . --fix

Prettier format

npx prettier --write .

TypeScript strict fixes

Some can be auto-fixed with ts-fix

Strategy 2: Dependency Fix

Reinstall dependencies

rm -rf node_modules package-lock.json npm install

Update specific package

npm update package-name

Fix peer dependencies

npm install --legacy-peer-deps

Strategy 3: Type Error Fix

// TS2322: Type mismatch // Before const value: string = 123; // After const value: number = 123;

// TS2531: Possibly null // Before element.innerHTML = 'text'; // After if (element) element.innerHTML = 'text';

// TS2339: Property missing // Before user.email // After if ('email' in user) user.email

Strategy 4: Runtime Error Fix

// TypeError: Cannot read property of undefined // Before const name = user.profile.name; // After const name = user?.profile?.name ?? 'Unknown';

// ReferenceError: not defined // Check: Is it imported? // Check: Is it in scope? // Check: Is it spelled correctly?

Strategy 5: Test Failure Fix

// Assertion failure - debug first console.log('Actual:', result); console.log('Expected:', expected);

// Async timeout test('async test', async () => { // Add proper awaits const result = await asyncOperation(); expect(result).toBeDefined(); }, 10000); // Increase timeout if needed

// Mock not working vi.mock('./module', () => ({ default: vi.fn().mockReturnValue('mocked'), }));

Recovery Protocol

┌─────────────────────────────────────────┐ │ ERROR DETECTED │ └─────────────────┬───────────────────────┘ ▼ ┌─────────────────────────────────────────┐ │ 1. CLASSIFY ERROR │ │ Syntax | Type | Runtime | Build | Test │ └─────────────────┬───────────────────────┘ ▼ ┌─────────────────────────────────────────┐ │ 2. IDENTIFY FIX │ │ Auto-fix | Manual | Delegate │ └─────────────────┬───────────────────────┘ ▼ ┌─────────────────────────────────────────┐ │ 3. APPLY FIX │ │ Make minimal, targeted change │ └─────────────────┬───────────────────────┘ ▼ ┌─────────────────────────────────────────┐ │ 4. VERIFY FIX │ │ tsc && eslint && npm test │ └─────────────────┬───────────────────────┘ ▼ ┌─────────┴─────────┐ │ Fixed? │ └─────────┬─────────┘ Yes │ No │ │ │ ▼ │ ▼ ┌─────┐ │ ┌─────────────────┐ │ Done│ │ │ Increment retry │ └─────┘ │ │ (max 3) │ │ └────────┬────────┘ │ ▼ │ ┌─────────────────┐ │ │ Retry < 3? │ │ └────────┬────────┘ │ Yes │ No │ │ │ │ │ ▼ │ ▼ │ ┌──────┐ │ ┌────────┐ └───│Retry │ │ │Escalate│ └──────┘ │ └────────┘

Prevention Strategies

• TypeScript Strict Mode - Catch errors at compile time

• ESLint Rules - Enforce best practices

• Pre-commit Hooks - Validate before commit

• Unit Tests - Catch regressions

• Code Review - Human verification