Add async dispose support

Author: malthe

.github/workflows/main.yml

@@ -89,8 +89,8 @@ jobs:
     strategy:
       matrix:
         version:
-          - 18.x
-          - 20.x
+          - 18
+          - 20
     runs-on: ubuntu-latest
     needs: [build]
     timeout-minutes: 3
@@ -138,10 +138,12 @@ jobs:
           set -o pipefail
           PGSSLMODE=disable node main.cjs | tee /dev/stderr | grep -q false
           PGSSLMODE=require node main.cjs | tee /dev/stderr | grep -q true
+          [[ -d v$NODE_VERSION ]] && cd v$NODE_VERSION
           npx tsc
           PGSSLMODE=disable node main.mjs | tee /dev/stderr | grep -q false
           PGSSLMODE=require node main.mjs | tee /dev/stderr | grep -q true
         env:
+          NODE_VERSION: ${{ matrix.version }}
           NODE_EXTRA_CA_CERTS: ${{ github.workspace }}/ssl-cert-snakeoil.pem
           PGPORT: ${{ job.services.postgres.ports[5432] }}
           PGUSER: postgres

CHANGES.md

@@ -4,6 +4,9 @@ In next release ...
   connected when the promise returns. The `Client` symbol is now a
   type instead of a value.
 
+- Add `[Symbol.asyncDispose]` method to support [Explicit Resource
+  Management](https://github.com/tc39/proposal-explicit-resource-management).
+
 - Add `off` method to disable event listening.
 
 - Remove dependency on

README.md

@@ -58,6 +58,12 @@ try {
 }
 ```
 
+With TypeScript 5.2+ there is also support for `await using`:
+```typescript
+await using client = await connect();
+// Will be disposed of automatically at the end of the block.
+```
+
 Waiting on the result (i.e., result iterator) returns the complete query result.
 
 ```typescript

examples/connect/main.cjs

@@ -1,5 +1,6 @@
 const { connect } = require('ts-postgres');
-module.exports = connect().then((client) => {
+module.exports = (async () => {
+    const client = await connect();
     console.log('Encrypted: ' + client.encrypted);
-    return client.end();
-});
+    await client.end();
+})();

examples/connect/main.mts

@@ -1,4 +1,3 @@
 import { connect } from 'ts-postgres';
-const client = await connect();
+await using client = await connect();
 console.log('Encrypted: ' + client.encrypted);
-await client.end();

examples/connect/package.json

@@ -1,7 +1,7 @@
 {
     "devDependencies": {
         "@types/node": "^20.0",
-        "typescript": "^4.8"
+        "typescript": "^5.2"
     },
     "dependencies": {
         "ts-postgres": "^2.0"

examples/connect/v18/main.mts

@@ -0,0 +1,4 @@
+import { connect } from 'ts-postgres';
+const client = await connect();
+console.log('Encrypted: ' + client.encrypted);
+await client.end();

package.json

@@ -27,7 +27,7 @@
     },
     "license": "MIT",
     "engines": {
-        "node": ">=18.0.0"
+        "node": ">=18.0"
     },
     "scripts": {
         "lint": "eslint -c .eslintrc.json --ext .ts src test",

src/client.ts

@@ -759,6 +759,10 @@ export class ClientImpl {
         }
     }
 
+    [Symbol.asyncDispose]() {
+        return this.end();
+    }
+
     private send() {
         if (this.mustDrain || !this.connected) return;
         this.sendUsing(this.writer);