semantic-memory-mcp/docs/PHASE_2_TDD_SUMMARY.md

# Phase 2 TDD Summary - REST API Implementation

## 🎯 Current Test Status

**Total Tests: 17 tests** (12 passing + 5 new API tests)

### ✅ Passing Tests (14 total)

**Core Infrastructure (12 tests):**
- 3 Auth tests (JWT functionality)
- 4 Memory service structure tests
- 2 Memory service integration tests
- 3 Memory operations tests (placeholders)

**API Endpoints (2 tests):**
- ✅ `test_health_endpoint` - Health check working
- ✅ `test_invalid_route_returns_404` - Proper 404 handling

### ❌ Failing Tests (3 tests) - These Guide Implementation

**API Endpoints needing implementation:**

1. **`test_add_fact_endpoint`** - POST /api/facts
   - **Expected**: Should accept JSON and return 201
   - **Current**: Returns error (endpoint not implemented)
   - **Action**: Implement fact creation endpoint

2. **`test_search_facts_endpoint`** - GET /api/facts/search
   - **Expected**: Should return search results with 200
   - **Current**: Returns error (endpoint not implemented)
   - **Action**: Implement search endpoint

3. **`test_malformed_json_returns_400`** - Error handling
   - **Expected**: Should return 400 for bad JSON
   - **Current**: Returns 404 (wrong error type)
   - **Action**: Fix error handling middleware

## 📋 Implementation Plan (TDD-Driven)

### Step 1: Implement API Handlers

**Files to create/modify:**
```
src/api/handlers.rs       # Request handlers
src/api/rest.rs           # REST endpoint definitions
```

**Endpoints to implement:**
```rust
// POST /api/facts
async fn add_fact(
    service: web::Data<MemoryService>,
    payload: web::Json<FactRequest>
) -> Result<HttpResponse, ServerError> {
    // TODO: Implement fact creation
}

// GET /api/facts/search
async fn search_facts(
    service: web::Data<MemoryService>,
    query: web::Query<SearchParams>
) -> Result<HttpResponse, ServerError> {
    // TODO: Implement search
}
```

### Step 2: Update API Configuration

**File: `src/api/config.rs`**
```rust
pub fn configure_api(cfg: &mut web::ServiceConfig) {
    cfg.service(
        web::scope("/api")
            .route("/health", web::get().to(health_check))
            .route("/facts", web::post().to(add_fact))
            .route("/facts/search", web::get().to(search_facts))
    );
}
```

### Step 3: Implement Request/Response Types

**File: `src/api/types.rs` (new)**
```rust
use serde::{Deserialize, Serialize};

#[derive(Deserialize)]
pub struct FactRequest {
    pub namespace: String,
    pub content: String,
}

#[derive(Deserialize)]
pub struct SearchParams {
    pub q: String,
    pub limit: Option<usize>,
}

#[derive(Serialize)]
pub struct FactResponse {
    pub id: String,
    pub namespace: String,
    pub content: String,
    pub created_at: String,
}
```

### Step 4: Implement Memory Service Operations

**File: `src/memory/service.rs` (expand)**
```rust
impl MemoryService {
    // ... existing code ...
    
    pub async fn add_fact(
        &self,
        namespace: &str,
        content: &str
    ) -> Result<Fact> {
        let store = self.get_store();
        // TODO: Use semantic-memory to add fact
    }
    
    pub async fn search_facts(
        &self,
        query: &str,
        limit: usize
    ) -> Result<Vec<Fact>> {
        let store = self.get_store();
        // TODO: Use semantic-memory to search
    }
}
```

### Step 5: Fix Error Handling

**File: `src/error.rs` (expand)**
```rust
impl From<actix_web::error::JsonPayloadError> for ServerError {
    fn from(err: actix_web::error::JsonPayloadError) -> Self {
        ServerError::ApiError(err.to_string())
    }
}
```

## 🎯 Expected Test Results After Implementation

| Test | Current Status | Expected Status |
|------|---------------|-----------------|
| `test_health_endpoint` | ✅ PASS | ✅ PASS |
| `test_invalid_route_returns_404` | ✅ PASS | ✅ PASS |
| `test_add_fact_endpoint` | ❌ FAIL | ✅ PASS |
| `test_search_facts_endpoint` | ❌ FAIL | ✅ PASS |
| `test_malformed_json_returns_400` | ❌ FAIL | ✅ PASS |

**Final: 5/5 API tests passing**

## 🚀 Next Steps

1. **Implement API handlers** in `src/api/handlers.rs`
2. **Update API routing** in `src/api/config.rs`
3. **Add request/response types** in `src/api/types.rs`
4. **Expand memory service operations**
5. **Fix error handling** for JSON parsing
6. **Run tests** to verify implementation

## 📁 Files to Create/Modify

```
📁 src/api/
├── types.rs          # NEW: Request/Response types
├── handlers.rs       # NEW: API handlers
└── config.rs         # MODIFY: Add new routes

📁 src/memory/
└── service.rs        # MODIFY: Add operations

📁 src/
└── error.rs          # MODIFY: Add error conversions
```

## ✅ TDD Compliance

- **Tests written first** ✅
- **Tests describe expected behavior** ✅
- **Failing tests guide implementation** ✅
- **Clear implementation path** ✅
- **All tests will remain permanent** ✅

The failing tests perfectly illustrate the TDD process - they tell us exactly what functionality is missing and what the expected behavior should be.