feat: implement 'isConnected' helper function

src/postgres/__tests__/base-pg-store.test.ts

@@ -118,4 +118,15 @@ describe('BasePgStore', () => {
     expect(sqlTransactionContext.getStore()).toBeUndefined();
     expect(db.sql).toEqual(obj);
   });
+
+  test('isConnected returns true when the connection is alive', async () => {
+    const connected = await db.isConnected();
+    expect(connected).toBe(true);
+  });
+
+  test('isConnected returns false when the connection is not alive', async () => {
+    jest.spyOn(db, 'sql').mockRejectedValueOnce(new Error('Connection lost'));
+    const connected = await db.isConnected();
+    expect(connected).toBe(false);
+  });
 });

src/postgres/base-pg-store.ts

@@ -84,6 +84,19 @@ export abstract class BasePgStore {
       isProdEnv ? this.sql`CONCURRENTLY` : this.sql``
     } ${this.sql(viewName)}`;
   }
+
+  /**
+   * Checks if the database connection is alive.
+   * @returns True if connected, false otherwise.
+   */
+  async isConnected(): Promise<boolean> {
+    try {
+      await this.sql`SELECT NOW()`;
+      return true;
+    } catch (error) {
+      return false;
+    }
+  }
 }
 
 /**
@@ -114,4 +127,7 @@ export abstract class BasePgStoreModule {
   async refreshMaterializedView(viewName: string): Promise<void> {
     return this.parent.refreshMaterializedView(viewName);
   }
+  async isConnected(): Promise<boolean> {
+    return this.parent.isConnected();
+  }
 }