# B1.2: Error Enum Design - COMPLETE ✅

**Date**: 2026-02-17
**Status**: ✅ COMPLETE (Already Implemented)

## Finding

The `do-memory-core/src/error/` module already contains a **well-designed error enum** that meets all requirements from B1.2:

### Existing Design Strengths

1. **✅ Uses thiserror**: Automatic error trait implementations
2. **✅ Comprehensive variants**: 15+ error types covering all domains
3. **✅ Context preservation**: Each error provides clear context
4. **✅ Specialized errors**: `CacheError`, `RelationshipError` modules
5. **✅ Helper methods**: `is_recoverable()`, `as_relationship_error()`, etc.
6. **✅ Test coverage**: 8 unit tests validating error behavior
7. **✅ Conversion impls**: From implementations for common error types

### Error Variants

| Variant | Usage | Recoverable |
|---------|-------|-------------|
| `Storage(String)` | Storage backend errors | ✅ Yes |
| `EpisodeNotFound(Uuid)` | Episode lookup failures | ❌ No |
| `Pattern(String)` | Pattern operation errors | ❌ No |
| `Embedding(anyhow::Error)` | Embedding provider errors | ✅ Yes |
| `Serialization(serde_json::Error)` | JSON/bincode errors | ❌ No |
| `ValidationFailed(String)` | Input validation | ❌ No |
| `Cache(CacheError)` | Cache operations | Conditional |
| `Relationship(RelationshipError)` | Relationship errors | Conditional |
| And 7 more... | | |

## Impact on v0.1.16 Plan

**Original Estimate**: B1.2 (Design error enum) = 1.5h
**Actual**: **0h** (already exists!)

**Revised B1 Timeline**:
- B1.1: ✅ Complete baseline audit
- B1.2: ✅ **SKIP** (design already exists)
- B1.3-B1.7: Implement error handling (can start immediately!)
- B1.8-B1.9: Testing and validation

**Time Saved**: 1.5h can be reallocated to B1.3-B1.7 implementation.

## Next Steps: B1.3 (Implement in do-memory-core)

Since the error enum is ready, B1.3 can begin immediately:

### B1.3 Task: Replace unwrap() in do-memory-core (2h)

**Target**: Reduce do-memory-core from 262 unwrap/expect → ≤140

**Strategy**:
1. Start with high-impact files (most unwrap() calls)
2. Use existing `Error` enum variants
3. Replace `unwrap()` with `?` operator
4. Add context using `Error::storage()`, `Error::validation()`, etc.

**Priority Files** (by unwrap count):
- TODO: Count per file to prioritize

**Example Conversion**:
```rust
// Before
let episode = episodes.get(id).unwrap();

// After
let episode = episodes
    .get(id)
    .ok_or_else(|| Error::EpisodeNotFound(id))?;
```

## Conclusion

B1.2 is complete without any work needed. The existing error design is production-ready and exceeds the requirements. We can proceed directly to B1.3 implementation.

---

**Part of**: GOAP v0.1.16 Phase B execution
**Next**: B1.3 (Implement error handling in do-memory-core)
**Time Saved**: 1.5h reallocated to implementation
