Error Scenario Testing

Error Scenario Testing

Overview

Test error handling by forcing error conditions. Don't commit error handling code without testing error paths.

Forcing Error Conditions

Methods:

• Add test mode flags to enable error injection
• Create test seam commands to trigger errors
• Temporarily modify code to force failures (revert after testing)
• Use environment variables to enable error testing

See references/error-injection.md for detailed error injection patterns.

Maze Generation Error Testing

For maze generation failures:

• Add forceMazeFailure() test seam command
• Modify maze generation to fail after N attempts
• Test fallback maze creation
• Verify console warnings appear

See references/maze-generation-errors.md for specific patterns.

Error Testing Checklist

• Error condition can be triggered
• Error handling code executes
• Fallback behavior works correctly
• User experience is acceptable
• Console warnings/logs appear
• Game doesn't crash

Test Mode Pattern

See references/error-injection.md for test mode implementation pattern.

Test Seam Error Injection

Add test seam commands to trigger errors:

// Force error conditions via test seam
window.__TEST__.commands.forceMazeFailure = () => {
  // Force maze generation to fail
  this.mazeGenerator.forceFailure = true;
};

window.__TEST__.commands.restoreMazeGeneration = () => {
  // Restore normal maze generation
  this.mazeGenerator.forceFailure = false;
};

Error scenario test commands:

window.__TEST__.commands = {
  forceMazeFailure: () => {
    this.mazeGenerator.forceFailure = true;
  },
  restoreMazeGeneration: () => {
    this.mazeGenerator.forceFailure = false;
  },
  triggerAssetLoadError: () => {
    // Simulate asset load failure
    this.assetLoader.simulateError = true;
  },
  restoreAssetLoading: () => {
    this.assetLoader.simulateError = false;
  }
};

Test error handling paths:

# Test error scenario
agent-browser eval "window.__TEST__.commands.forceMazeFailure()"
agent-browser eval "window.__TEST__.commands.generateMaze()"
# Verify fallback behavior
agent-browser eval "window.__TEST__.commands.restoreMazeGeneration()"

Error Recovery Patterns

Retry logic with configurable attempts:

async function generateWithRetry(
  generator: () => Promise<Result>,
  maxAttempts: number = 3
): Promise<Result> {
  for (let attempt = 1; attempt <= maxAttempts; attempt++) {
    try {
      return await generator();
    } catch (error) {
      console.warn(`Attempt ${attempt} failed:`, error);
      if (attempt === maxAttempts) {
        throw new Error(`Failed after ${maxAttempts} attempts`);
      }
      // Wait before retry
      await sleep(1000 * attempt); // Exponential backoff
    }
  }
  throw new Error('Max attempts reached');
}

Fallback mechanisms for critical operations:

async function loadAssetWithFallback(
  assetKey: string,
  primaryUrl: string,
  fallbackUrl: string
): Promise<void> {
  try {
    this.load.image(assetKey, primaryUrl);
  } catch (error) {
    console.warn(`Failed to load ${assetKey} from primary URL, using fallback`);
    this.load.image(assetKey, fallbackUrl);
  }
}

Console warning patterns:

if (!this.textures.exists('asset-key')) {
  console.warn('Asset not found:', 'asset-key');
  console.warn('Using fallback placeholder');
  // Use fallback
}

Graceful degradation strategies:

create() {
  try {
    // Try primary implementation
    this.initPrimaryFeature();
  } catch (error) {
    console.warn('Primary feature failed, using fallback:', error);
    // Graceful degradation
    this.initFallbackFeature();
  }
}

Verification Checklists

Verify error handling works:

## Error Handling Verification

- [ ] Error condition can be triggered
- [ ] Error handling code executes
- [ ] Fallback behavior works correctly
- [ ] User experience is acceptable
- [ ] Console warnings/logs appear
- [ ] Game doesn't crash

Test fallback mechanisms:

# Test fallback by forcing error
agent-browser eval "window.__TEST__.commands.forceMazeFailure()"
agent-browser eval "window.__TEST__.commands.generateMaze()"
# Verify fallback maze is created
agent-browser eval "window.__TEST__.gameState().maze"

Check console warnings:

# Check for console warnings
agent-browser console | grep -i "warn\|error"

# Verify warnings appear for error scenarios
agent-browser eval "window.__TEST__.commands.forceMazeFailure()"
agent-browser console

Validate recovery behavior:

# Test recovery after error
agent-browser eval "window.__TEST__.commands.forceMazeFailure()"
agent-browser eval "window.__TEST__.commands.generateMaze()"
agent-browser eval "window.__TEST__.commands.restoreMazeGeneration()"
agent-browser eval "window.__TEST__.commands.generateMaze()"
# Verify normal generation works after recovery

Resources

• references/error-injection.md - Test mode flags, test seam commands, environment variables
• references/maze-generation-errors.md - Specific patterns for maze generation failures