/error-resolver

name: Error Resolver
description: Legacy error-resolution reference archive retained for migration. Do not route user tasks here; use systematic-debugging for active bug, stack-trace, and root-cause work.

Error Resolver

Legacy reference archive for first-principle error diagnosis across languages and frameworks.

Routing Status

This directory is retained because it contains substantial analysis, pattern, and replay material. It is not an active `code-quality` route owner. Route user-facing bug, stack-trace, and root-cause tasks to `systematic-debugging`.

Core Philosophy

**The 5-step Error Resolution Process:**

1. CLASSIFY  ->  2. PARSE  ->  3. MATCH  ->  4. ANALYZE  ->  5. RESOLVE
     |              |             |             |              |
  What type?    Extract key    Known       Root cause      Fix +
               information    pattern?     analysis       Prevent

Quick Start

When you encounter an error:

1. **Paste the full error** (including stack trace if available) 2. **Provide context** (what were you trying to do?) 3. **Share relevant code** (the file/function involved)

Error Classification Framework

Primary Categories

| Category | Indicators | Common Causes | |----------|------------|---------------| | **Syntax** | Parse error, Unexpected token | Typos, missing brackets, invalid syntax | | **Type** | TypeError, type mismatch | Wrong data type, null/undefined access | | **Reference** | ReferenceError, NameError | Undefined variable, scope issues | | **Runtime** | RuntimeError, Exception | Logic errors, invalid operations | | **Network** | ECONNREFUSED, timeout, 4xx/5xx | Connection issues, wrong URL, server down | | **Permission** | EACCES, PermissionError | File/directory access, sudo needed | | **Dependency** | ModuleNotFound, Cannot find module | Missing package, version mismatch | | **Configuration** | Config error, env missing | Wrong settings, missing env vars | | **Database** | Connection refused, query error | DB down, wrong credentials, bad query | | **Memory** | OOM, heap out of memory | Memory leak, large data processing |

Secondary Attributes

• **Severity**: Fatal / Error / Warning / Info
• **Scope**: Build-time / Runtime / Test-time
• **Origin**: User code / Framework / Third-party / System

Analysis Workflow

Step 1: Classify

Identify the error category by examining:

• Error name/code (e.g., `ENOENT`, `TypeError`)
• Error message keywords
• Where it occurred (compile, runtime, test)

Step 2: Parse

Extract key information:

- Error code: [specific code if any]
- File path: [where the error originated]
- Line number: [exact line if available]
- Function/method: [context of the error]
- Variable/value: [what was involved]
- Stack trace depth: [how deep is the call stack]

Step 3: Match Patterns

Check against known error patterns:

• See `patterns/` directory for language-specific patterns
• Match error signatures to known solutions
• Check replay history for previous solutions

Step 4: Root Cause Analysis

Apply the **5 Whys** technique:

Error: Cannot read property 'name' of undefined
  Why 1? -> user object is undefined
  Why 2? -> API call returned null
  Why 3? -> User ID doesn't exist in database
  Why 4? -> ID was from stale cache
  Why 5? -> Cache invalidation not implemented

Root Cause: Missing cache invalidation logic

Step 5: Resolve

Generate actionable solution: 1. **Immediate fix** - Get it working now 2. **Proper fix** - The right way to solve it 3. **Prevention** - How to avoid in the future

Output Format

When resolving an error, provide:

## Error Diagnosis

**Classification**: [Category] / [Severity] / [Scope]

**Error Signature**:
- Code: [error code]
- Type: [error type]
- Location: [file:line]

## Root Cause

[Explanation of why this error occurred]

**Contributing Factors**:
1. [Factor 1]
2. [Factor 2]

## Solution

### Immediate Fix
[Quick steps to resolve]

### Code Change
[Specific code to add/modify]

### Verification
[How to verify the fix works]

## Prevention

[How to prevent this error in the future]

## Replay Tag

[Unique identifier for this solution - for future reference]

Replay System

The replay system records successful solutions for future reference.

Recording a Solution

After resolving an error, record it:

# Create solution record in project
mkdir -p .claude/error-solutions

# Solution file format: [error-type]-[hash].yaml

Solution Record Format

# .claude/error-solutions/[error-signature].yaml
id: "nodejs-module-not-found-express"
created: "2024-01-15T10:30:00Z"
updated: "2024-01-20T14:22:00Z"

error:
  type: "dependency"
  category: "ModuleNotFound"
  language: "nodejs"
  pattern: "Cannot find module 'express'"
  context: "npm project, missing dependency"

diagnosis:
  root_cause: "Package not installed or node_modules corrupted"
  factors:
    - "Missing npm install after git clone"
    - "Corrupted node_modules directory"
    - "Package not in package.json"

solution:
  immediate:
    - "Run: npm install express"
  proper:
    - "Check package.json has express listed"
    - "Run: rm -rf node_modules && npm install"
  code_change: null

verification:
  - "Run the application again"
  - "Check express is in node_modules"

prevention:
  - "Add npm install to project setup docs"
  - "Use npm ci in CI/CD pipelines"

metadata:
  occurrences: 5
  last_resolved: "2024-01-20T14:22:00Z"
  success_rate: 1.0
  tags: ["nodejs", "npm", "dependency"]

Replay Lookup

When encountering an error: 1. Generate error signature from the error message 2. Search `.claude/error-solutions/` for matching patterns 3. If found, apply the recorded solution 4. If new, proceed with full analysis and record the solution

Error Signature Generation

signature = hash(
  error_type +
  error_code +
  normalized_message +  # remove specific values
  language +
  framework
)

Example transformations: