Merge pull request #37 from panates/implement-js-disposal

Implement js disposal

DOCUMENTATION.md

@@ -497,6 +497,19 @@ connection.on('terminate', () => {
 await connection.close(30000); // will wait 30 secs before terminate the connection
 ```
 
+`Connection` already supports [TC30 Explicit Resource Management](https://github.com/tc39/proposal-explicit-resource-management) proposal.
+
+```ts
+import { Connection } from 'postgresql-client';
+{
+    // connection will be automatically closed when this scope ends
+    await using connection = new Connection('postgres://localhost');
+    await connection.connect();    
+}
+
+```
+
+
 ##### .execute()
 
 Executes single or multiple SQL scripts
@@ -795,7 +808,7 @@ import { Pool } from 'postgresql-client';
 const pool = new Pool('postgres://localhost');
 const connection = await pool.acquire();
 // ...
-await connection.relese();
+await connection.close();
 ````
 
 ##### .close()

README.md

@@ -30,6 +30,7 @@ Enterprise level PostgreSQL client for NodeJs
 - Low memory utilization and boosted performance with Shared Buffers
 - Supports Clear text, MD5 and SASL password algorithms
 - Can return both array and object rows
+- Auto disposal with "using" syntax ([TC30 Explicit Resource Management](https://github.com/tc39/proposal-explicit-resource-management))
 
 
 ## Installation

src/connection/connection.ts

@@ -18,7 +18,7 @@ import { PreparedStatement } from './prepared-statement.js';
 export type NotificationMessage = Protocol.NotificationResponseMessage;
 export type NotificationCallback = (msg: NotificationMessage) => any;
 
-export class Connection extends SafeEventEmitter {
+export class Connection extends SafeEventEmitter implements AsyncDisposable {
   protected readonly _pool?: Pool;
   protected readonly _intlCon: IntlConnection;
   protected readonly _notificationListeners = new SafeEventEmitter();
@@ -305,4 +305,8 @@ export class Connection extends SafeEventEmitter {
       throw e;
     });
   }
+
+  [Symbol.asyncDispose](): Promise<void> {
+    return this.close();
+  }
 }

src/connection/cursor.ts

@@ -9,7 +9,7 @@ import { parseRow } from '../util/parse-row.js';
 import { Portal } from './portal.js';
 import { PreparedStatement } from './prepared-statement.js';
 
-export class Cursor extends SafeEventEmitter {
+export class Cursor extends SafeEventEmitter implements AsyncDisposable {
   private readonly _statement: PreparedStatement;
   private readonly _portal: Portal;
   private readonly _parsers: AnyParseFunction[];
@@ -95,4 +95,8 @@ export class Cursor extends SafeEventEmitter {
       })
       .toPromise();
   }
+
+  [Symbol.asyncDispose](): Promise<void> {
+    return this.close();
+  }
 }

src/connection/prepared-statement.ts

@@ -21,7 +21,7 @@ import { Portal } from './portal.js';
 let statementCounter = 0;
 let portalCounter = 0;
 
-export class PreparedStatement extends SafeEventEmitter {
+export class PreparedStatement extends SafeEventEmitter implements AsyncDisposable {
   private readonly _connection: Connection;
   private readonly _sql: string = '';
   private readonly _name: string = '';
@@ -242,4 +242,8 @@ export class PreparedStatement extends SafeEventEmitter {
     }
     this.emit('close');
   }
+
+  [Symbol.asyncDispose](): Promise<void> {
+    return this.close();
+  }
 }

src/constants.ts

@@ -2,6 +2,9 @@ import { Protocol } from './protocol/protocol.js';
 
 import DataFormat = Protocol.DataFormat;
 
+// @ts-ignore
+Symbol.asyncDispose ??= Symbol('Symbol.asyncDispose');
+
 export { DataFormat };
 export const DEFAULT_COLUMN_FORMAT = DataFormat.binary;
 

test/B-connection/01-connection.spec.ts

@@ -246,21 +246,18 @@ describe('Connection', function () {
     const x = await connection.query('select count(*) from test.dummy_table1', { autoCommit: false });
     expect(x.rows?.length).toStrictEqual(1);
     expect(x.rows?.[0][0]).toStrictEqual(1);
-    /*
-                await connection.startTransaction();
-                try {
-                    await connection.execute('savepoint sv1');
-                    await connection.execute('invalid sql');
-                } catch (e) {
-                }
-                try {
-                    await connection.execute('select 1');
-                } catch (e) {
-                    await connection.execute('rollback to sv1');
-                }
-                await connection.execute('select 2');
-                await connection.execute('select 3');
-        */
+
     await connection.close();
   });
+
+  it('should automatically close with "using" syntax', async function () {
+    let closed = false;
+    {
+      await using conn = new Connection();
+      await conn.connect();
+      conn.on('close', () => (closed = true));
+      expect(conn.state).toStrictEqual(ConnectionState.READY);
+    }
+    expect(closed).toStrictEqual(true);
+  });
 });

test/B-connection/06-cursor.spec.ts

@@ -81,4 +81,17 @@ describe('Cursor support', function () {
     await cursor?.close();
     expect(count).toStrictEqual(10);
   });
+
+  it('should automatically close with "using" syntax', async function () {
+    let closed = false;
+    {
+      const result = await connection.query(`select * from customers order by id`, { objectRows: false, cursor: true });
+      await using cursor = result.cursor!;
+      expect(cursor).toBeDefined();
+      cursor.on('close', () => (closed = true));
+      const row = await cursor?.next();
+      expect(row[0]).toStrictEqual(1);
+    }
+    expect(closed).toStrictEqual(true);
+  });
 });