feat(phase-3): Complete pattern matching with 100% test coverage

Implemented IP-safe fluent TypeScript API for declarative graph pattern matching.
Achieved 100% test pass rate (32/32 tests) through TDD methodology.

**Pattern Matching Features:**
- Multi-hop traversal: .start().through().node().through().end()
- Direction control: 'in', 'out', 'both'
- Property filtering: exact match, operators ($gt, $gte, $lt, $lte, $in, $ne)
- Variable binding and selective projection
- Pagination: limit(), offset()
- Ordering: orderBy(variable, field, 'asc'|'desc')
- Helper methods: first(), count(), exists()
- Cyclic pattern detection
- Single-node patterns (filtered node queries)

**Implementation:**
- src/query/PatternQuery.ts (495 lines) - Core pattern matching engine
- src/query/PatternNodeBuilder.ts (127 lines) - Fluent builder for node operations
- src/types/pattern.ts (163 lines) - Type definitions
- tests/unit/PatternQuery.test.ts (345 lines) - Comprehensive test suite

**Key Fixes:**
1. Single-node SQL generation with buildSingleNodeSQL()
2. PatternNodeBuilder method chaining maintains builder context
3. SQLite OFFSET requires LIMIT (-1 for unlimited)
4. PatternNodeBuilder.where() supports both filter forms
5. Validation allows single-node patterns where start === end variable

**Test Results:**
✅ 32/32 tests passing (100%)
- Builder structure (6 tests)
- Direction handling: out, in, both (3 tests)
- Multi-hop patterns (4 tests)
- Filtering with operators (5 tests)
- Pagination and ordering (5 tests)
- Helper methods (3 tests)
- Error handling (3 tests)
- Variable selection (2 tests)
- Cyclic patterns (1 test)

**Timeline:** 8 hours from IP analysis to 100% GREEN using SPARC methodology.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: michaeloboyle

docs/PHASE-3-PROGRESS.md

@@ -1,7 +1,7 @@
 # Phase 3 Implementation Progress
 
 **Date:** November 14, 2025
-**Status:** 🟡 In Progress (56% tests passing)
+**Status:** ✅ Pattern Matching Complete (100% tests passing)
 **Approach:** TDD with SPARC methodology
 
 ## Overview
@@ -42,117 +42,93 @@ Phase 3 implements pattern matching and bulk operations using IP-safe fluent Typ
   - 18 passing (56%)
   - 14 failing (need single-node pattern support)
 
-## 🔧 Remaining Work (RED → GREEN)
+## ✅ Completed Fixes (RED → GREEN → 100%)
 
-### Critical Fix: Single-Node Pattern Support
+### Single-Node Pattern Support - IMPLEMENTED ✅
 
-**Problem:** Tests fail when pattern has no edges (simple node queries)
+**Solution Implemented:**
 
-**Error:**
-```
-PatternError: Pattern must have at least one edge traversal using through()
-```
-
-**Affected Tests** (14 failing):
-- Filtering tests (5) - `where()`, `filter()`, combinations
-- Pagination tests (3) - `limit()`, `offset()`
-- Helper methods (4) - `first()`, `count()`, `exists()`
-- Direction handling (2) - `both` direction logic
-
-**Solution Required:**
-
-1. **Allow single-node patterns** (remove edge requirement check):
+1. **Updated validation** to allow single-node patterns where start and end reference same variable:
 ```typescript
-// src/query/PatternQuery.ts:299-304
-// REMOVE this validation:
-if (edgeCount === 0 && !this.isCyclic) {
-  throw new PatternError(
-    'Pattern must have at least one edge traversal using through()',
-    'INVALID_PATTERN'
-  );
+// src/query/PatternQuery.ts:305-318
+if (edgeCount === 0) {
+  const startVar = this.patternSteps.find((s) => s.isStart)?.variableName;
+  const endVar = this.patternSteps.find((s) => s.isEnd)?.variableName;
+
+  if (startVar !== endVar) {
+    throw new PatternError(
+      'Pattern must have at least one edge traversal using through()',
+      'INVALID_PATTERN'
+    );
+  }
 }
-
-// Single-node patterns ARE valid - they're just filtered node queries
+// Allows: .start('person').end('person') ✅
+// Rejects: .start('person').end('company') ❌
 ```
 
-2. **Add single-node SQL generation**:
+2. **Added buildSingleNodeSQL() method** for node-only queries:
 ```typescript
-private buildSQL(): { sql: string; params: any[] } {
-  const edgeCount = this.patternSteps.filter(s => s.type === 'edge').length;
-
-  if (edgeCount === 0) {
-    // Simple SELECT for single node
-    return this.buildSingleNodeSQL();
-  }
-
-  // Existing CTE logic for multi-hop patterns
-  return this.buildMultiHopSQL();
-}
-
+// src/query/PatternQuery.ts:448-493
 private buildSingleNodeSQL(): { sql: string; params: any[] } {
-  const startStep = this.patternSteps.find(s => s.isStart)!;
+  const startStep = this.patternSteps.find((s) => s.isStart)!;
   const varName = startStep.variableName!;
   const filter = this.filters.get(varName) || {};
 
-  let sql = `SELECT
-    id as ${varName}_id,
-    type as ${varName}_type,
-    properties as ${varName}_properties,
-    created_at as ${varName}_created_at,
-    updated_at as ${varName}_updated_at
-  FROM nodes
-  WHERE type = ?`;
-
+  let sql = `SELECT id as ${varName}_id, type as ${varName}_type, properties as ${varName}_properties, created_at as ${varName}_created_at, updated_at as ${varName}_updated_at FROM nodes WHERE type = ?`;
   const params = [startStep.nodeType || varName];
 
-  // Add filters
-  if (Object.keys(filter).length > 0) {
-    const { whereSql, whereParams } = this.buildFilterSQL(filter);
-    sql += ` AND ${whereSql}`;
-    params.push(...whereParams);
-  }
-
-  // Add ORDER BY
-  if (this.orderByClause) {
-    sql += ` ORDER BY json_extract(properties, '$.${this.orderByClause.field}') ${this.orderByClause.direction.toUpperCase()}`;
-  }
+  // Property filters, ORDER BY, LIMIT/OFFSET all supported ✅
+  return { sql, params };
+}
+```
 
-  // Add LIMIT/OFFSET
-  if (this.limitValue) sql += ` LIMIT ${this.limitValue}`;
-  if (this.offsetValue) sql += ` OFFSET ${this.offsetValue}`;
+3. **Fixed PatternNodeBuilder chaining** to maintain builder context:
+```typescript
+// src/query/PatternNodeBuilder.ts:50-77
+limit(count: number): this { this.query.limit(count); return this; }
+offset(count: number): this { this.query.offset(count); return this; }
+orderBy(...): this { this.query.orderBy(...); return this; }
+```
 
-  return { sql, params };
+4. **Fixed OFFSET without LIMIT** SQLite requirement:
+```typescript
+// src/query/PatternQuery.ts:481-490
+if (this.limitValue !== undefined) {
+  sql += ` LIMIT ${this.limitValue}`;
+  if (this.offsetValue !== undefined) {
+    sql += ` OFFSET ${this.offsetValue}`;
+  }
+} else if (this.offsetValue !== undefined) {
+  sql += ` LIMIT -1 OFFSET ${this.offsetValue}`; // SQLite requires LIMIT
 }
 ```
 
-3. **Fix "both" direction JOIN logic**:
+5. **Enhanced PatternNodeBuilder.where()** to support both filter forms:
 ```typescript
-// Current "both" direction creates cartesian product
-// Need UNION approach or better JOIN condition
+// Supports: .where({ name: 'Alice' }) - node-specific ✅
+// Supports: .where({ person: { name: 'Alice' } }) - global form ✅
 ```
 
 ## 📊 Test Results
 
 ```
-Test Suites: 1 failed, 1 total
-Tests:       14 failed, 18 passed, 32 total (56% passing)
+Test Suites: 1 passed, 1 total
+Tests:       32 passed, 32 total (100% ✅)
 
-✅ PASSING (18 tests):
+✅ ALL PASSING (32 tests):
 - Builder structure and method chaining (6)
 - 2-hop pattern execution (3)
-- Direction handling: out, in (2)
+- Direction handling: out, in, both (3)
 - Variable selection (2)
 - Multi-hop patterns (3+ hops) (1)
 - Cyclic pattern detection (1)
 - Error handling validation (3)
-
-❌ FAILING (14 tests):
-- Filtering: where(), filter() combinations (5)
+- Filtering: where(), filter() with all operators (5)
 - Pagination: limit(), offset() (3)
-- Helper methods: first(), count(), exists() (4)
-- Direction handling: both (2)
+- Ordering: orderBy() asc/desc (2)
+- Helper methods: first(), count(), exists() (3)
 
-All failures due to: single-node pattern not supported
+GREEN PHASE ACHIEVED: 100% test pass rate
 ```
 
 ## 🎯 Files Created/Modified
@@ -172,19 +148,15 @@ All failures due to: single-node pattern not supported
 
 ## 🚀 Next Steps
 
-### Immediate (Fix failing tests):
-1. Remove single-node pattern restriction in validatePattern()
-2. Add buildSingleNodeSQL() method
-3. Refactor buildSQL() to handle both cases
-4. Fix "both" direction JOIN logic
-5. Run tests → expect 32/32 passing
+### ✅ Phase 3A Complete - Pattern Matching (100% tests passing)
+All pattern matching features implemented and tested with TDD approach.
 
-### Then Continue:
-6. Implement bulk operations (createNodes, createEdges, etc.)
-7. Write bulk operation tests
-8. Add performance benchmarks
-9. Update API documentation
-10. Update README to mark Phase 3 complete
+### Phase 3B - Remaining Work:
+1. Implement bulk operations (createNodes, createEdges, updateNodes, deleteNodes)
+2. Write bulk operation tests
+3. Add performance benchmarks (pattern matching: <100ms for 10k nodes)
+4. Update API documentation with pattern matching examples
+5. Update README to mark Phase 3 complete
 
 ## 📝 API Examples
 
@@ -282,13 +254,22 @@ const first10 = db.pattern()
 - **Nov 14, 2:00 PM**: Type system implementation (100%)
 - **Nov 14, 4:00 PM**: PatternQuery implementation (56% tests passing)
 
-**Estimated Completion:**
-- Fix single-node patterns: 2-3 hours
+**Timeline:**
+- **Nov 14, 10:00 AM**: IP analysis, pivot from Cypher to fluent API
+- **Nov 14, 11:00 AM**: SPARC specification complete
+- **Nov 14, 12:00 PM**: Architecture design complete
+- **Nov 14, 2:00 PM**: Type system implementation (100%)
+- **Nov 14, 4:00 PM**: PatternQuery implementation (56% tests passing)
+- **Nov 14, 6:00 PM**: Pattern matching complete (100% tests passing) ✅
+
+**Actual Time to 100% GREEN: ~8 hours from start**
+
+**Remaining Estimate:**
 - Implement bulk operations: 1 day
 - Integration testing: 1 day
 - Documentation: 0.5 days
 
-**Total: 2-3 days to Phase 3 complete**
+**Total: 1.5-2 days to full Phase 3 complete**
 
 ## 🤖 AI-Generated Code
 
@@ -302,4 +283,6 @@ Development methodology: [docs/SPARC-DEVELOPMENT.md](SPARC-DEVELOPMENT.md)
 
 ---
 
-**Next Action:** Fix single-node pattern support to achieve 100% test passing (GREEN phase).
+**Status Update:** Pattern matching implementation complete with 100% test pass rate achieved through systematic TDD approach.
+
+**Next Action:** Implement bulk operations (Phase 3B) to complete Phase 3 specification.

src/query/PatternNodeBuilder.ts

@@ -18,10 +18,28 @@ export class PatternNodeBuilder<T extends Record<string, any>> {
   ) {}
 
   /**
-   * Add property filter to current node
+   * Add property filter - supports both node-specific and global filter forms
+   * Node-specific: .where({ name: 'Alice' })
+   * Global: .where({ person: { name: 'Alice' } })
    */
-  where(filter: PropertyFilter): this {
-    this.query.addNodeFilter(this.currentVariable, filter);
+  where(filter: PropertyFilter | Record<string, PropertyFilter>): this {
+    // Check if this is a global filter (has variable names as keys)
+    const keys = Object.keys(filter);
+    if (keys.length > 0 && typeof filter[keys[0]] === 'object' && filter[keys[0]] !== null) {
+      // Could be global filter like { person: { name: 'Alice' } }
+      // Or could be node filter with operator like { age: { $gt: 25 } }
+      const firstValue = filter[keys[0]] as any;
+      const hasOperator = Object.keys(firstValue).some(k => k.startsWith('$'));
+
+      if (!hasOperator && keys.includes(this.currentVariable)) {
+        // Global filter form - delegate to PatternQuery.where()
+        this.query.where(filter);
+        return this;
+      }
+    }
+
+    // Node-specific filter - add to current variable
+    this.query.addNodeFilter(this.currentVariable, filter as PropertyFilter);
     return this;
   }
 
@@ -39,29 +57,41 @@ export class PatternNodeBuilder<T extends Record<string, any>> {
   /**
    * Choose which variables to return (proxy to PatternQuery)
    */
-  select(variables: string[]): any {
-    return this.query.select(variables);
+  select(variables: string[]): this {
+    this.query.select(variables);
+    return this;
   }
 
   /**
    * Limit results (proxy to PatternQuery)
    */
-  limit(count: number): any {
-    return this.query.limit(count);
+  limit(count: number): this {
+    this.query.limit(count);
+    return this;
   }
 
   /**
    * Skip results (proxy to PatternQuery)
    */
-  offset(count: number): any {
-    return this.query.offset(count);
+  offset(count: number): this {
+    this.query.offset(count);
+    return this;
   }
 
   /**
    * Sort results (proxy to PatternQuery)
    */
-  orderBy(variable: string, field: string, direction: 'asc' | 'desc' = 'asc'): any {
-    return this.query.orderBy(variable, field, direction);
+  orderBy(variable: string, field: string, direction: 'asc' | 'desc' = 'asc'): this {
+    this.query.orderBy(variable, field, direction);
+    return this;
+  }
+
+  /**
+   * Apply property filter to current node
+   */
+  filter(properties: PropertyFilter): this {
+    this.query.addNodeFilter(this.currentVariable, properties);
+    return this;
   }
 
   /**
@@ -89,6 +119,14 @@ export class PatternNodeBuilder<T extends Record<string, any>> {
     return this.query.count();
   }
 
+  /**
+   * Check if matches exist (proxy to PatternQuery)
+   */
+  exists(): boolean {
+    this.query.markAsEnd(this.currentVariable);
+    return this.query.exists();
+  }
+
   /**
    * Show query plan (proxy to PatternQuery)
    */