fix(node): Ensure mysql integration works without callback (#9222)

Turns out my "improvement" here actually broke streaming the query
response 😬 as in that case you may not provide a callback.

This PR fixes this by using `query.on('end')` instead in that case to
finish the span.

Fixes #9207

Author: mydea

packages/node-integration-tests/suites/tracing-new/auto-instrument/mysql/withoutCallback/scenario.ts

@@ -13,6 +13,12 @@ const connection = mysql.createConnection({
   password: 'docker',
 });
 
+connection.connect(function (err: unknown) {
+  if (err) {
+    return;
+  }
+});
+
 const transaction = Sentry.startTransaction({
   op: 'transaction',
   name: 'Test Transaction',
@@ -22,10 +28,18 @@ Sentry.configureScope(scope => {
   scope.setSpan(transaction);
 });
 
-connection.query('SELECT 1 + 1 AS solution');
-connection.query('SELECT NOW()', ['1', '2']);
+const query = connection.query('SELECT 1 + 1 AS solution');
+const query2 = connection.query('SELECT NOW()', ['1', '2']);
+
+query.on('end', () => {
+  transaction.setTag('result_done', 'yes');
 
-// Wait a bit to ensure the queries completed
-setTimeout(() => {
-  transaction.finish();
-}, 500);
+  query2.on('end', () => {
+    transaction.setTag('result_done2', 'yes');
+
+    // Wait a bit to ensure the queries completed
+    setTimeout(() => {
+      transaction.finish();
+    }, 500);
+  });
+});

packages/node-integration-tests/suites/tracing-new/auto-instrument/mysql/withoutCallback/test.ts

@@ -8,6 +8,10 @@ test('should auto-instrument `mysql` package when using query without callback',
 
   assertSentryTransaction(envelope[2], {
     transaction: 'Test Transaction',
+    tags: {
+      result_done: 'yes',
+      result_done2: 'yes',
+    },
     spans: [
       {
         description: 'SELECT 1 + 1 AS solution',

packages/tracing-internal/src/node/integrations/mysql.ts

@@ -84,7 +84,7 @@ export class Mysql implements LazyLoadedIntegration<MysqlConnection> {
     }
 
     function finishSpan(span: Span | undefined): void {
-      if (!span) {
+      if (!span || span.endTimestamp) {
         return;
       }
 
@@ -128,9 +128,14 @@ export class Mysql implements LazyLoadedIntegration<MysqlConnection> {
           });
         }
 
-        return orig.call(this, options, values, function () {
+        // streaming, no callback!
+        const query = orig.call(this, options, values) as { on: (event: string, callback: () => void) => void };
+
+        query.on('end', () => {
           finishSpan(span);
         });
+
+        return query;
       };
     });
   }