chore: add test coverage configuration and refactor KnowledgeStore to use persistent connection

pr/memory/knowledge_store.py

@@ -31,13 +31,13 @@ class KnowledgeEntry:
 class KnowledgeStore:
     def __init__(self, db_path: str):
         self.db_path = db_path
+        self.conn = sqlite3.connect(self.db_path, check_same_thread=False)
         self.semantic_index = SemanticIndex()
         self._initialize_store()
         self._load_index()
 
     def _initialize_store(self):
-        conn = sqlite3.connect(self.db_path, check_same_thread=False)
-        cursor = conn.cursor()
+        cursor = self.conn.cursor()
 
         cursor.execute('''
             CREATE TABLE IF NOT EXISTS knowledge_entries (
@@ -62,22 +62,17 @@ class KnowledgeStore:
             CREATE INDEX IF NOT EXISTS idx_created ON knowledge_entries(created_at DESC)
         ''')
 
-        conn.commit()
-        conn.close()
+        self.conn.commit()
 
     def _load_index(self):
-        conn = sqlite3.connect(self.db_path, check_same_thread=False)
-        cursor = conn.cursor()
+        cursor = self.conn.cursor()
 
         cursor.execute('SELECT entry_id, content FROM knowledge_entries')
         for row in cursor.fetchall():
             self.semantic_index.add_document(row[0], row[1])
 
-        conn.close()
-
     def add_entry(self, entry: KnowledgeEntry):
-        conn = sqlite3.connect(self.db_path, check_same_thread=False)
-        cursor = conn.cursor()
+        cursor = self.conn.cursor()
 
         cursor.execute('''
             INSERT OR REPLACE INTO knowledge_entries
@@ -94,14 +89,12 @@ class KnowledgeStore:
             entry.importance_score
         ))
 
-        conn.commit()
-        conn.close()
+        self.conn.commit()
 
         self.semantic_index.add_document(entry.entry_id, entry.content)
 
     def get_entry(self, entry_id: str) -> Optional[KnowledgeEntry]:
-        conn = sqlite3.connect(self.db_path, check_same_thread=False)
-        cursor = conn.cursor()
+        cursor = self.conn.cursor()
 
         cursor.execute('''
             SELECT entry_id, category, content, metadata, created_at, updated_at, access_count, importance_score
@@ -117,9 +110,7 @@ class KnowledgeStore:
                 SET access_count = access_count + 1
                 WHERE entry_id = ?
             ''', (entry_id,))
-            conn.commit()
-
-            conn.close()
+            self.conn.commit()
 
             return KnowledgeEntry(
                 entry_id=row[0],
@@ -132,15 +123,13 @@ class KnowledgeStore:
                 importance_score=row[7]
             )
 
-        conn.close()
         return None
 
     def search_entries(self, query: str, category: Optional[str] = None,
                       top_k: int = 5) -> List[KnowledgeEntry]:
         search_results = self.semantic_index.search(query, top_k * 2)
 
-        conn = sqlite3.connect(self.db_path, check_same_thread=False)
-        cursor = conn.cursor()
+        cursor = self.conn.cursor()
 
         entries = []
         for entry_id, score in search_results:
@@ -174,12 +163,10 @@ class KnowledgeStore:
             if len(entries) >= top_k:
                 break
 
-        conn.close()
         return entries
 
     def get_by_category(self, category: str, limit: int = 20) -> List[KnowledgeEntry]:
-        conn = sqlite3.connect(self.db_path, check_same_thread=False)
-        cursor = conn.cursor()
+        cursor = self.conn.cursor()
 
         cursor.execute('''
             SELECT entry_id, category, content, metadata, created_at, updated_at, access_count, importance_score
@@ -202,12 +189,10 @@ class KnowledgeStore:
                 importance_score=row[7]
             ))
 
-        conn.close()
         return entries
 
     def update_importance(self, entry_id: str, importance_score: float):
-        conn = sqlite3.connect(self.db_path, check_same_thread=False)
-        cursor = conn.cursor()
+        cursor = self.conn.cursor()
 
         cursor.execute('''
             UPDATE knowledge_entries
@@ -215,18 +200,15 @@ class KnowledgeStore:
             WHERE entry_id = ?
         ''', (importance_score, time.time(), entry_id))
 
-        conn.commit()
-        conn.close()
+        self.conn.commit()
 
     def delete_entry(self, entry_id: str) -> bool:
-        conn = sqlite3.connect(self.db_path, check_same_thread=False)
-        cursor = conn.cursor()
+        cursor = self.conn.cursor()
 
         cursor.execute('DELETE FROM knowledge_entries WHERE entry_id = ?', (entry_id,))
         deleted = cursor.rowcount > 0
 
-        conn.commit()
-        conn.close()
+        self.conn.commit()
 
         if deleted:
             self.semantic_index.remove_document(entry_id)
@@ -234,8 +216,7 @@ class KnowledgeStore:
         return deleted
 
     def get_statistics(self) -> Dict[str, Any]:
-        conn = sqlite3.connect(self.db_path, check_same_thread=False)
-        cursor = conn.cursor()
+        cursor = self.conn.cursor()
 
         cursor.execute('SELECT COUNT(*) FROM knowledge_entries')
         total_entries = cursor.fetchone()[0]
@@ -254,8 +235,6 @@ class KnowledgeStore:
         cursor.execute('SELECT SUM(access_count) FROM knowledge_entries')
         total_accesses = cursor.fetchone()[0] or 0
 
-        conn.close()
-
         return {
             'total_entries': total_entries,
             'total_categories': total_categories,