Error Recovery Patterns

Error Recovery Patterns

Overview

Systematic approach to handling and recovering from common errors during task execution. Provides recovery strategies, retry patterns, and fallback approaches for different error types.

Common Error Types

1. Compilation Errors

Symptoms:

• TypeScript compilation fails
• Syntax errors (missing braces, semicolons)
• Type mismatches
• Import path errors
• Method name mismatches

Recovery Strategy:

1. Read error message carefully: Understand what's wrong
2. Fix syntax/type errors immediately: Don't proceed with broken code
3. Re-run compilation check: npx tsc --noEmit
4. If errors persist: Check for missing imports or type definitions

Common Patterns:

• Syntax errors: Check for missing/extra braces, parentheses, semicolons
• Type mismatches: Verify interface compatibility, check actual types
• Import errors: Use relative paths, check file existence
• Method name mismatches: Check actual method names in source code

When to skip: Never skip compilation errors - must fix before proceeding

2. Test Failures

Symptoms:

• Tests fail with assertion errors
• Tests timeout
• Tests are flaky (pass/fail intermittently)
• Test setup/teardown fails

Recovery Strategy:

1. Read test output: Understand what failed and why
2. Classify failure: Is test flaky or code broken?
3. Fix code if broken: Update implementation to match test expectations
4. Skip test if flaky: Document why test was skipped
5. Re-run tests: Verify fix or skip

Common Patterns:

• Assertion failures: Code doesn't match test expectations
• Timeouts: Test takes too long (increase timeout or optimize code)
• Flaky tests: Non-deterministic behavior (seed RNG, fix timing)
• Setup failures: Test environment not configured correctly

When to skip: Only skip if test is flaky and not critical for task

3. Tool Failures

Symptoms:

• API errors (401, 403, 500)
• Network timeouts
• Invalid credentials
• Tool unavailable
• Rate limiting

Recovery Strategy:

1. Check error message: Understand root cause
2. If API key missing/invalid: Skip tool usage (don't retry)
3. If network timeout: Retry with exponential backoff (max 3 times)
4. If tool unavailable: Use alternative approach
5. Document fallback: Explain why alternative was used

Common Patterns:

• API errors: Check credentials, verify API key, check rate limits
• Network timeouts: Retry with delays, check network connectivity
• Tool unavailable: Service down, use alternative tool
• Rate limiting: Wait and retry, or use alternative approach

When to skip: Skip if tool consistently failing or not critical

4. Browser Testing Failures

Symptoms:

• Browser commands timeout
• Elements not found
• Test seam unavailable
• Scene navigation fails

Recovery Strategy:

1. Check timeout: Increase timeout or use polling
2. Verify element exists: Check DOM, wait for element
3. Check test seam: Verify window.__TEST__ is available
4. Use fallback: Console logs, screenshots, code review

Common Patterns:

• Timeouts: Increase timeout, use polling instead of fixed wait
• Element not found: Wait for element, check selector
• Test seam unavailable: Check scene initialization, wait for ready
• Navigation fails: Verify scene key, check scene registration

When to skip: Skip if browser testing not critical, use code review instead

Retry Patterns with Limits

Exponential Backoff

Pattern:

• First retry: 1 second delay
• Second retry: 2 second delay
• Third retry: 4 second delay
• After 3 retries: Skip and use alternative

When to use:

• Transient failures (timeouts, network issues)
• Likely to succeed on retry
• No alternative available

When NOT to use:

• API key errors (won't succeed on retry)
• Tool unavailable (service down)
• Invalid credentials (won't succeed on retry)

Retry Limits

Maximum retries: 3 attempts

After 3 retries:

1. Skip tool/step
2. Use alternative approach
3. Document why skipped

Fallback Strategies

Strategy 1: Use Alternative Tool

When primary tool fails:

• Use different tool with same functionality
• Example: agent-browser fails → use code review + compilation check

Pattern:

1. Identify alternative tool
2. Try alternative
3. If alternative works, continue
4. If alternative fails, try next fallback

Strategy 2: Graceful Degradation

When cost-incurring tool fails:

• Use free alternative
• Example: ElevenLabs TTS fails → use console.log for verification

Pattern:

1. Check if free alternative exists
2. Use free alternative
3. Document why alternative was used

Strategy 3: Skip Non-Critical Steps

When step is not critical:

• Skip step and continue
• Document why skipped
• Example: Visual verification skipped → use code review

Pattern:

1. Verify step is not critical
2. Skip step
3. Document why skipped
4. Continue with remaining steps

Strategy 4: Code Review + Compilation Check

When browser testing fails:

• Use code review to verify implementation
• Run TypeScript compilation check
• Verify logic matches requirements

Pattern:

1. Review code changes
2. Run npx tsc --noEmit
3. Verify logic matches requirements
4. Document verification method

Error Classification

Critical Errors (Must Fix)

• Compilation errors: Code won't run
• Type errors: Type safety violated
• Syntax errors: Code invalid

Action: Fix immediately, don't proceed

Non-Critical Errors (Can Skip)

• Visual verification: Can use code review
• Optional features: Not required for task
• Cost-incurring tools: Can use free alternatives

Action: Skip if alternative available

Transient Errors (Retry)

• Network timeouts: Likely to succeed on retry
• Rate limiting: Wait and retry
• Temporary service issues: Retry with backoff

Action: Retry with exponential backoff (max 3 times)

Recovery Workflow

Step 1: Classify Error

1. Read error message: Understand what failed
2. Identify error type: Compilation, test, tool, browser
3. Determine severity: Critical, non-critical, transient

Step 2: Choose Recovery Strategy

1. Critical errors: Fix immediately
2. Non-critical errors: Skip if alternative available
3. Transient errors: Retry with backoff

Step 3: Execute Recovery

1. Fix errors: Update code, fix syntax, correct types
2. Retry with backoff: Wait and retry (max 3 times)
3. Use alternative: Switch to different tool/approach
4. Skip step: Document why skipped

Step 4: Verify Recovery

1. Re-run checks: Compilation, tests, verification
2. Verify fix: Confirm error is resolved
3. Document recovery: Explain what was done

Best Practices

1. Fix errors immediately: Don't accumulate errors
2. Use retries wisely: Only for transient failures
3. Have fallback strategies: Always know alternative approach
4. Document recoveries: Explain why alternative was used
5. Don't retry forever: Set limits (max 3 retries)

Resources

• agent-workflow-guidelines skill - General workflow guidelines
• loop-detection-prevention skill - Prevent infinite retry loops
• typescript-incremental-check skill - TypeScript error patterns