refactor: Enhance arrayToVectorString method with validation and update schema comments

- Updated arrayToVectorString method to include validation for input type, length, and element types.
- Modified schema comments for clarity and consistency in the database migration files.
- Ensured that the embedding field in the entities table is validated to have exactly 4 dimensions.

Author: spences10

src/db/client.ts

@@ -29,8 +29,19 @@ export class DatabaseManager {
     return DatabaseManager.instance;
   }
 
-  // Convert array to vector string representation
-  private arrayToVectorString(numbers: number[]): string {
+  // Convert array to vector string representation with validation
+  private arrayToVectorString(numbers: number[] | undefined): string | null {
+    if (!numbers || !Array.isArray(numbers)) {
+      return null;
+    }
+    // Validate vector dimensions match schema (4 dimensions for testing)
+    if (numbers.length !== 4) {
+      throw new Error(`Vector must have exactly 4 dimensions, got ${numbers.length}`);
+    }
+    // Validate all elements are numbers
+    if (!numbers.every(n => typeof n === 'number' && !isNaN(n))) {
+      throw new Error('Vector must contain only valid numbers');
+    }
     return `[${numbers.join(', ')}]`;
   }
 
@@ -60,7 +71,7 @@ export class DatabaseManager {
         args: [
           entity.name,
           entity.entityType,
-          entity.embedding ? this.arrayToVectorString(entity.embedding) : null
+          this.arrayToVectorString(entity.embedding)
         ],
       });
 

src/db/migrations/schema.ts

@@ -1,23 +1,23 @@
 export const schema = [
-  // Create entities table
-  `CREATE TABLE IF NOT EXISTS entities (
+	// Create entities table
+	`CREATE TABLE IF NOT EXISTS entities (
     name TEXT PRIMARY KEY,
     entity_type TEXT NOT NULL,
     embedding F32_BLOB(4), -- 4 dimensions for testing
     created_at DATETIME DEFAULT CURRENT_TIMESTAMP
   )`,
 
-  // Create observations table
-  `CREATE TABLE IF NOT EXISTS observations (
+	// Create observations table
+	`CREATE TABLE IF NOT EXISTS observations (
     id INTEGER PRIMARY KEY AUTOINCREMENT,
     entity_name TEXT NOT NULL,
     content TEXT NOT NULL,
     created_at DATETIME DEFAULT CURRENT_TIMESTAMP,
     FOREIGN KEY (entity_name) REFERENCES entities(name)
   )`,
 
-  // Create relations table
-  `CREATE TABLE IF NOT EXISTS relations (
+	// Create relations table
+	`CREATE TABLE IF NOT EXISTS relations (
     id INTEGER PRIMARY KEY AUTOINCREMENT,
     source TEXT NOT NULL,
     target TEXT NOT NULL,
@@ -27,12 +27,12 @@ export const schema = [
     FOREIGN KEY (target) REFERENCES entities(name)
   )`,
 
-  // Create indexes
-  `CREATE INDEX IF NOT EXISTS idx_entities_name ON entities(name)`,
-  `CREATE INDEX IF NOT EXISTS idx_observations_entity ON observations(entity_name)`,
-  `CREATE INDEX IF NOT EXISTS idx_relations_source ON relations(source)`,
-  `CREATE INDEX IF NOT EXISTS idx_relations_target ON relations(target)`,
+	// Create indexes
+	`CREATE INDEX IF NOT EXISTS idx_entities_name ON entities(name)`,
+	`CREATE INDEX IF NOT EXISTS idx_observations_entity ON observations(entity_name)`,
+	`CREATE INDEX IF NOT EXISTS idx_relations_source ON relations(source)`,
+	`CREATE INDEX IF NOT EXISTS idx_relations_target ON relations(target)`,
 
-// Create vector index for similarity search
-`CREATE INDEX IF NOT EXISTS idx_entities_embedding ON entities(libsql_vector_idx(embedding))`
+	// Create vector index for similarity search
+	`CREATE INDEX IF NOT EXISTS idx_entities_embedding ON entities(libsql_vector_idx(embedding))`,
 ];