Error Learning System

This skill implements continuous learning from session errors to prevent repeated mistakes.

Trigger Point

Called by yolo1 skill at Step 8 (after commit, before push) via:

Invoke Skill: error-learner
Context: Current session transcript, commit SHA

Core Logic

┌─────────────────────────────────────────────────────────────────┐
│                    ERROR LEARNER FLOW                           │
├─────────────────────────────────────────────────────────────────┤
│                                                                 │
│  1. SCAN SESSION                                                │
│     ├─ Parse tool outputs for error patterns                    │
│     ├─ Identify: TypeScript, build, git, runtime errors         │
│     └─ Extract error type, message, file, context               │
│                                                                 │
│  2. CHECK SAME-SESSION REPETITION                               │
│     ├─ Count occurrences of each error type in THIS session     │
│     └─ Group by error signature (type + normalized message)     │
│                                                                 │
│  3. BRANCH: USER-REPORTED, REPETITIVE, OR ONE-OFF?              │
│     │                                                           │
│     ├─ IF user explicitly reports a process error:              │
│     │   ├─ Treat as CONFIRMED PATTERN immediately               │
│     │   ├─ Skip occurrence counting (user feedback = pattern)   │
│     │   ├─ Research + document + update KB                      │
│     │   └─ Record with trigger: "user-reported" in JSON         │
│     │                                                           │
│     ├─ IF 2+ same-type errors in session:                       │
│     │   ├─ Research root cause                                  │
│     │   ├─ Determine best practice / solution                   │
│     │   ├─ Report to main assistant with:                       │
│     │   │   - Error pattern description                         │
│     │   │   - Root cause analysis                               │
│     │   │   - Recommended KB update                             │
│     │   └─ Main assistant updates knowledge files               │
│     │                                                           │
│     └─ IF one-off error (< 2 occurrences):                      │
│         ├─ Store in .claude/data/session-errors.json            │
│         └─ Include: error signature, context, timestamp         │
│                                                                 │
│  4. CHECK CROSS-SESSION PATTERNS                                │
│     ├─ Load .claude/data/session-errors.json                    │
│     ├─ Check if current error matches previous session errors   │
│     └─ IF match found (same error in different session):        │
│         ├─ Promote to "pattern" status                          │
│         ├─ Research solution                                    │
│         └─ Report to main assistant for KB update               │
│                                                                 │
└─────────────────────────────────────────────────────────────────┘

Error Detection Scope

What to Scan

1. TypeScript Errors

   • TS####: error codes
   • Cannot find module, Property does not exist
   • Type 'X' is not assignable to type 'Y'
   • Path alias resolution failures

2. Build Errors

   • npm run build failures
   • Webpack/Vite compilation errors
   • Module resolution errors

3. Git Errors

   • Push/pull failures (403, 401, conflicts)
   • Branch operation failures
   • Merge conflicts

4. Runtime Errors

   • API endpoint failures
   • Database connection issues
   • Environment variable missing

Error Signature Format

{
  "type": "typescript|build|git|runtime",
  "code": "TS2339|BUILD_FAIL|GIT_403|...",
  "pattern": "normalized error message pattern",
  "example": "actual error message",
  "file": "path/to/file.ts (if applicable)",
  "context": "what operation was being performed"
}

Session Errors JSON Schema

File: .claude/data/session-errors.json

{
  "version": "1.0.0",
  "errors": [
    {
      "id": "uuid",
      "signature": {
        "type": "typescript",
        "code": "TS2339",
        "pattern": "Property .* does not exist on type .*"
      },
      "occurrences": [
        {
          "session_date": "2025-01-15",
          "commit_sha": "abc123",
          "file": "apps/web/app/test/page.tsx",
          "message": "Property 'foo' does not exist on type 'Bar'",
          "context": "Adding test page component"
        }
      ],
      "status": "watching|pattern_detected|resolved",
      "first_seen": "2025-01-15T10:30:00Z",
      "last_seen": "2025-01-15T10:30:00Z",
      "occurrence_count": 1
    }
  ],
  "resolved_patterns": [
    {
      "signature": { "type": "...", "code": "...", "pattern": "..." },
      "resolution": "Description of fix applied to knowledge base",
      "kb_file_updated": ".claude/knowledge/error-learnings.md",
      "resolved_date": "2025-01-15T12:00:00Z"
    }
  ],
  "last_updated": "2025-01-15T10:30:00Z"
}

Workflow Steps

Step 1: Scan Current Session

Parse the session transcript for errors. Look in:

• Bash tool outputs (build logs, git errors)
• File read/write operations that failed
• Any error messages in assistant responses

Extract error signatures for each unique error encountered.

Step 2: Count Same-Session Occurrences

For each error signature found:

count = number of times this error type appeared in THIS session

Group errors by their normalized signature (ignore specific variable names, line numbers).

Step 3: Process Based on Repetition

IF Repetitive (count >= 2 in same session):

Research the error (MANDATORY WEB SEARCH):

1. Use WebSearch tool to find latest documentation:

   • Search: "[error code] [framework] best practice 2025" (e.g., "TS2339 TypeScript best practice 2025")
   • Search: "[error message] fix solution" for specific fixes
   • Search: "[library name] [version] breaking changes" if version-related

2. Use WebFetch tool to read official docs:

   • TypeScript errors → fetch typescript-lang.org docs
   • Next.js errors → fetch nextjs.org docs
   • React errors → fetch react.dev docs
   • Git errors → fetch git-scm.com docs

3. Extract from research:

   • What causes this error type?
   • What is the current best practice (as of latest docs)?
   • Is there a pre-flight check that would catch it?
   • Has the solution changed in recent versions?

4. Update knowledge with latest info:

   • Include version numbers where relevant
   • Note if behavior differs between versions
   • Link to official documentation source

Generate KB update recommendation:

## Error Pattern: [Error Code/Type]

**Trigger:** What causes this error
**Prevention:** Pre-flight check or workflow change
**Fix:** How to resolve when encountered

**Add to:** .claude/knowledge/[appropriate-file].md or .claude/workflows/[workflow].md

Report to main assistant with the recommendation. Main assistant will:

1. Review the recommendation
2. Edit the appropriate knowledge file
3. Add the pattern to resolved_patterns in session-errors.json

IF One-Off (count < 2 in same session):

Store for future tracking:

1. Load .claude/data/session-errors.json
2. Check if this error signature already exists
3. If exists: increment occurrence_count, add new occurrence
4. If new: create new error entry with status "watching"
5. Save updated JSON

Step 4: Cross-Session Pattern Check

On every invocation:

1. Load session-errors.json
2. For each error with status "watching":
   • If occurrence_count >= 2 AND occurrences span multiple sessions:
     • Mark as "pattern_detected"
     • Perform web search research (same as Step 3 - use WebSearch and WebFetch)
     • Report to main assistant for KB update with latest documentation findings

Knowledge File Targets

Based on error type, recommend updates to:

Error Type	Target File
TypeScript patterns	.claude/knowledge/error-learnings.md
Build workflow issues	.claude/workflows/typescript-verification.md
Git operations	.claude/knowledge/ci-cd-discipline.md
API/runtime errors	.claude/knowledge/error-learnings.md
SQL/database errors	.claude/knowledge/error-learnings.md
UX/CSS errors	.claude/knowledge/error-learnings.md
Infrastructure/deployment	.claude/knowledge/infrastructure-incidents.md
New error category	Add to .claude/knowledge/error-learnings.md

Output Format

When Updating KB (Repetitive Pattern)

## Error Pattern Detected (Same-Session)

**Pattern:** [error type] - [description]
**Occurrences:** [count] times in this session
**Root Cause:** [analysis]
**Prevention:** [recommended pre-flight check]

### Recommended KB Update

**File:** .claude/knowledge/[file].md
**Section:** [section name]
**Add:**

```markdown
[content to add]

Action: Main assistant should apply this update now.

### When Storing for Future (One-Off)

Error Logged for Cross-Session Tracking

Pattern: [error type] - [description] Status: Watching (first occurrence) File: .claude/data/session-errors.json updated

No KB update needed yet. Will promote to pattern if seen in future sessions.

### When Cross-Session Pattern Found

Cross-Session Pattern Detected

Pattern: [error type] - [description] Sessions affected: [count] sessions First seen: [date] Last seen: [date] Root Cause: [analysis]

Recommended KB Update

File: .claude/knowledge/[file].md Section: [section name] Add:

[content to add]

Action: Main assistant should apply this update now.

## Integration with yolo1

In `yolo1` Step 8 (after commit), add:

```markdown
### 8. Git Operations + Error Learning

- Commit with message: `feat({module}): {slice} - {scope}`
- **Invoke error-learner skill:**
  - Analyze session for error patterns
  - Check cross-session error history
  - If patterns found: Apply KB updates before push
- Push branch: `git push -u origin feature/{module}-{slice}`

Example: TypeScript Error Pattern

Session has 3 occurrences of:

TS2339: Property 'status' does not exist on type 'Response'

Error Learner Output:

## Error Pattern Detected (Same-Session)

**Pattern:** TS2339 - Property access on incorrect type
**Occurrences:** 3 times in this session
**Root Cause:** Using Response type instead of specific API response type
**Prevention:** Always read type definitions before accessing properties

### Recommended KB Update

**File:** .claude/knowledge/error-learnings.md
**Section:** Add new err-XXX entry or update existing pattern
**Add:**

```markdown
**Error Pattern:** `Property 'X' does not exist on type 'Response'`
- **Root Cause:** Generic `Response` type doesn't have custom properties
- **Solution:** Import and use specific response type (e.g., `ApiResponse<T>`)
- **Pre-flight:** Check type definition before accessing properties

Action: Main assistant should apply this update now.

## Maintenance

### Cleanup Old Entries

Entries in session-errors.json with:
- `status: "watching"` AND
- `last_seen` > 30 days ago AND
- `occurrence_count` == 1

Can be removed (truly one-off errors that didn't repeat).

### Archive Resolved Patterns

When an error is resolved:
1. Move from `errors` array to `resolved_patterns`
2. Include resolution details and KB file updated
3. Keep resolved_patterns for reference (prevents re-adding same fix)