Brummer MCP Server

--- sidebar_position: 3 --- # Error Detection Brummer's intelligent error detection helps you quickly identify and fix issues in your development workflow. ## How It Works Brummer continuously monitors process output for error patterns and provides real-time notifications and highlighting. ### Detection Pipeline ``` Process Output → Pattern Matching → Classification → Notification → UI Update ``` ## Built-in Patterns ### JavaScript/TypeScript Errors Brummer detects common JavaScript and TypeScript errors: ```javascript // Syntax errors SyntaxError: Unexpected token '}' at Module._compile (internal/modules/cjs/loader.js:723:23) // Runtime errors TypeError: Cannot read property 'map' of undefined at App.render (/src/App.js:15:20) // Reference errors ReferenceError: myVariable is not defined at processData (index.js:42:5) ``` ### Build Errors Framework-specific build errors are automatically detected: #### React ``` Failed to compile. ./src/App.js Module not found: Can't resolve './components/Header' ``` #### Vue ``` ERROR Failed to compile with 1 error error in ./src/App.vue Module Error (from ./node_modules/vue-loader/lib/index.js): ``` #### Next.js ``` Error: Page "/api/users/[id]" is missing exported function "default" ``` ### Test Failures Test framework failures are highlighted: #### Jest ``` FAIL src/utils.test.js ● utility functions › should format date correctly Expected: "2024-01-15" Received: "15-01-2024" ``` #### Mocha ``` 1) User API should create a new user: AssertionError: expected 201 to equal 200 ``` ### Linting Errors ESLint and other linter errors: ``` /src/components/Button.js 12:5 error 'PropTypes' is not defined no-undef 23:9 error Missing semicolon semi ``` ## Error Levels Brummer classifies errors into different severity levels: ### 🔴 Critical Errors - Build failures - Syntax errors - Unhandled exceptions - Process crashes ### 🟡 Warnings - Deprecation notices - Linting warnings - Performance warnings - Security advisories ### 🔵 Info - Debug messages - Build progress - Server startup messages ## Smart Features ### 1. Error Grouping Similar errors are grouped together: ``` ┌─ Errors (3 similar) ────────────────────────┐ │ TypeError: Cannot read property 'x' of null │ │ at calculatePosition (layout.js:45) │ │ at renderComponent (render.js:23) │ │ at updateUI (app.js:156) │ │ │ │ First occurrence: 10:23:45 │ │ Last occurrence: 10:24:12 │ │ Count: 47 │ └──────────────────────────────────────────────┘ ``` ### 2. Stack Trace Parsing Stack traces are parsed and made interactive: ``` Error: Connection timeout at Database.connect (/src/db/index.js:23:11) [Click to open] at startServer (/src/server.js:45:20) [Click to open] at main (/src/index.js:12:5) [Click to open] ``` ### 3. Error Context Brummer provides context around errors: ``` ┌─ Error Context ─────────────────────────────┐ │ File: /src/api/users.js │ │ Line: 67 │ │ Column: 15 │ │ │ │ 65: const user = await User.findById(id); │ │ 66: if (!user) { │ │ 67: throw new Error('User not found'); │ │ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ │ │ 68: } │ │ 69: return user; │ └─────────────────────────────────────────────┘ ``` ### 4. Suggested Fixes Common errors include suggested fixes: ``` Error: Module not found: 'express' Suggested fix: npm install express # or yarn add express ``` ## Custom Error Patterns ### Configuration File Add custom patterns in `.brummer.yaml`: ```yaml error_detection: patterns: - pattern: "CUSTOM_ERROR:(.*)" level: error group: "Custom Errors" - pattern: "DEPRECATED:(.*)" level: warning group: "Deprecations" - pattern: "TODO:(.*)" level: info group: "TODOs" ``` ### Regular Expressions Use regex for complex patterns: ```yaml error_detection: patterns: - pattern: "\\[ERROR\\]\\s+\\[(\\d{4}-\\d{2}-\\d{2})\\]\\s+(.*)" level: error capture_groups: - name: date - name: message ``` ### Pattern Priority Higher priority patterns are matched first: ```yaml error_detection: patterns: - pattern: "CRITICAL:.*" level: critical priority: 100 - pattern: "ERROR:.*" level: error priority: 50 ``` ## Error Actions ### Quick Actions Press `a` on an error for quick actions: 1. **Copy Error** - Copy full error to clipboard 2. **Open File** - Open error location in editor 3. **Search Similar** - Find similar errors 4. **Ignore Pattern** - Add to ignore list 5. **Report Issue** - Create GitHub issue ### Bulk Actions Select multiple errors with `Space` then: - **Mark as Resolved** - **Export to File** - **Create Issue** - **Add to Ignore** ## Filtering and Search ### Filter by Level ``` Ctrl+F → Level: error ``` ### Filter by Pattern ``` Ctrl+F → Pattern: "Cannot read property" ``` ### Filter by Time ``` Ctrl+F → After: 10:30:00 ``` ### Complex Filters ``` level:error AND file:*.test.js AND after:"5 minutes ago" ``` ## Error Statistics View error statistics with `Ctrl+S`: ``` ┌─ Error Statistics ──────────────────────────┐ │ Total Errors: 127 │ │ Unique Errors: 12 │ │ Error Rate: 2.1/min │ │ │ │ By Level: │ │ Critical: 3 │ │ Error: 45 │ │ Warning: 79 │ │ │ │ Top Errors: │ │ 1. Cannot read property (34) │ │ 2. Module not found (23) │ │ 3. Syntax error (15) │ └─────────────────────────────────────────────┘ ``` ## Integration with Tools ### VSCode Integration Click on file paths to open in VSCode: ```bash # Configure editor brummer config set editor "code --goto" ``` ### MCP Integration External tools can query errors: ```javascript // Get recent errors const errors = await mcp.call('brummer.getErrors', { level: 'error', limit: 10 }); ``` ## Performance Considerations ### Pattern Matching Performance - Patterns are compiled once at startup - Most specific patterns first - Use anchors in regex (`^` and `$`) ### Memory Usage - Circular buffer for error storage - Configurable retention period - Automatic cleanup of old errors ```yaml error_detection: max_errors: 1000 retention_minutes: 60 ``` ## Troubleshooting ### Errors Not Detected 1. Check pattern configuration 2. Verify error format matches pattern 3. Check if pattern is too specific 4. Enable debug mode to see matching ### Too Many False Positives 1. Make patterns more specific 2. Add ignore patterns 3. Adjust detection sensitivity 4. Use negative lookahead in regex ### Performance Issues 1. Reduce number of patterns 2. Optimize regex patterns 3. Decrease retention period 4. Disable unused detectors ## Best Practices 1. **Start with built-in patterns** and add custom ones as needed 2. **Use specific patterns** to avoid false positives 3. **Group related errors** for better organization 4. **Set up ignore patterns** for known non-issues 5. **Monitor error rates** to catch regression 6. **Export critical errors** for post-mortem analysis 7. **Integrate with your workflow** using MCP