fix(promise): forward pool error events

lib/promise/pool.js

@@ -15,7 +15,13 @@ class PromisePool extends EventEmitter {
     super();
     this.pool = pool;
     this.Promise = thePromise || Promise;
-    inheritEvents(pool, this, ['acquire', 'connection', 'enqueue', 'release']);
+    inheritEvents(pool, this, [
+      'acquire',
+      'connection',
+      'enqueue',
+      'error',
+      'release',
+    ]);
   }
 
   getConnection() {

promise.d.ts

@@ -94,6 +94,7 @@ export interface Pool extends Connection {
 
   releaseConnection(connection: PoolConnection): void;
 
+  on(event: 'error', listener: (err: NodeJS.ErrnoException) => any): this;
   on(event: 'connection', listener: (connection: PoolConnection) => any): this;
   on(event: 'acquire', listener: (connection: PoolConnection) => any): this;
   on(event: 'release', listener: (connection: PoolConnection) => any): this;

test/integration/promise-wrappers/test-promise-wrappers.test.mts

@@ -259,6 +259,7 @@ await describe('testEventsPool', async () => {
       acquire: 0,
       connection: 0,
       enqueue: 0,
+      error: 0,
       release: 0,
     };
     for (const eventName in expectedListeners) {
@@ -291,6 +292,14 @@ await describe('testEventsPool', async () => {
           ++events;
         }.bind(pool)
       )
+      .once(
+        'error',
+        function (err: Error) {
+          strict.equal(this, pool);
+          strict.equal(err.message, 'pool error');
+          ++events;
+        }.bind(pool)
+      )
       .once(
         'release',
         function () {
@@ -302,9 +311,10 @@ await describe('testEventsPool', async () => {
     pool.pool.emit('acquire');
     pool.pool.emit('connection');
     pool.pool.emit('enqueue');
+    pool.pool.emit('error', new Error('pool error'));
     pool.pool.emit('release');
 
-    strict.equal(events, 4, 'wrong number of pool connection events');
+    strict.equal(events, 5, 'wrong number of pool connection events');
 
     for (const eventName in expectedListeners) {
       strict.equal(

test/tsc-build/promise/createPool/on.test.ts

@@ -0,0 +1,14 @@
+import { mysqlp as mysql } from '../../index.test.js';
+import { access } from '../baseConnection.test.js';
+
+const pool = mysql.createPool(access);
+
+pool.on('error', (err) => {
+  const code: string | undefined = err.code;
+  code;
+  err.message;
+});
+
+pool.on('connection', (connection) => {
+  connection.threadId;
+});