feat: MySQL Tracing Support (#3088)

* feat: node-mysql tracing integration

* Use // instead of /** */

* fix: Require mysql.Connection directly through mysql/lib/Connection.js

* ref: Align span description

Co-authored-by: Katie Byers <[email protected]>
Co-authored-by: Daniel Griesser <[email protected]>

Author: 3 people

packages/tracing/src/integrations/index.ts

@@ -1,2 +1,3 @@
 export { Express } from './express';
+export { Mysql } from './mysql';
 export { Mongo } from './mongo';

packages/tracing/src/integrations/mysql.ts

@@ -0,0 +1,68 @@
+import { Hub } from '@sentry/hub';
+import { EventProcessor, Integration } from '@sentry/types';
+import { dynamicRequire, fill, logger } from '@sentry/utils';
+
+interface MysqlConnection {
+  prototype: {
+    query: () => void;
+  };
+}
+
+/** Tracing integration for node-mysql package */
+export class Mysql implements Integration {
+  /**
+   * @inheritDoc
+   */
+  public static id: string = 'Mysql';
+
+  /**
+   * @inheritDoc
+   */
+  public name: string = Mysql.id;
+
+  /**
+   * @inheritDoc
+   */
+  public setupOnce(_: (callback: EventProcessor) => void, getCurrentHub: () => Hub): void {
+    let connection: MysqlConnection;
+
+    try {
+      // Unfortunatelly mysql is using some custom loading system and `Connection` is not exported directly.
+      connection = dynamicRequire(module, 'mysql/lib/Connection.js');
+    } catch (e) {
+      logger.error('Mysql Integration was unable to require `mysql` package.');
+      return;
+    }
+
+    // The original function will have one of these signatures:
+    //    function (callback) => void
+    //    function (options, callback) => void
+    //    function (options, values, callback) => void
+    fill(connection.prototype, 'query', function(orig: () => void) {
+      return function(this: unknown, options: unknown, values: unknown, callback: unknown) {
+        const scope = getCurrentHub().getScope();
+        const parentSpan = scope?.getSpan();
+        const span = parentSpan?.startChild({
+          description: typeof options === 'string' ? options : (options as { sql: string }).sql,
+          op: `db`,
+        });
+
+        if (typeof callback === 'function') {
+          return orig.call(this, options, values, function(err: Error, result: unknown, fields: unknown) {
+            span?.finish();
+            callback(err, result, fields);
+          });
+        }
+
+        if (typeof values === 'function') {
+          return orig.call(this, options, function(err: Error, result: unknown, fields: unknown) {
+            span?.finish();
+            values(err, result, fields);
+          });
+        }
+
+        return orig.call(this, options, values, callback);
+      };
+    });
+  }
+}