fix(instrumentation-mysql2): instrument connection on 3.11.5 (#2579)

Author: pichlermarc

package-lock.json

@@ -50,7 +50,7 @@
     "@types/mocha": "7.0.2",
     "@types/node": "18.18.14",
     "@types/semver": "7.5.8",
-    "mysql2": "3.11.3",
+    "mysql2": "3.11.5",
     "nyc": "15.1.0",
     "rimraf": "5.0.10",
     "semver": "7.6.3",

plugins/node/opentelemetry-instrumentation-mysql2/package.json

@@ -31,6 +31,7 @@ import type * as mysqlTypes from 'mysql2';
 import { MySQL2InstrumentationConfig } from './types';
 import {
   getConnectionAttributes,
+  getConnectionPrototypeToInstrument,
   getDbStatement,
   getSpanName,
   once,
@@ -56,7 +57,7 @@ export class MySQL2Instrumentation extends InstrumentationBase<MySQL2Instrumenta
         ['>=1.4.2 <4'],
         (moduleExports: any) => {
           const ConnectionPrototype: mysqlTypes.Connection =
-            moduleExports.Connection.prototype;
+            getConnectionPrototypeToInstrument(moduleExports.Connection);
           if (isWrapped(ConnectionPrototype.query)) {
             this._unwrap(ConnectionPrototype, 'query');
           }

plugins/node/opentelemetry-instrumentation-mysql2/src/instrumentation.ts

@@ -146,3 +146,22 @@ export const once = (fn: Function) => {
     return fn(...args);
   };
 };
+
+export function getConnectionPrototypeToInstrument(connection: any) {
+  const connectionPrototype = connection.prototype;
+  const basePrototype = Object.getPrototypeOf(connectionPrototype);
+
+  // [email protected] included a refactoring, where most code was moved out of the `Connection` class and into a shared base
+  // so we need to instrument that instead, see https://github.com/sidorares/node-mysql2/pull/3081
+  // This checks if the functions we're instrumenting are there on the base - we cannot use the presence of a base
+  // prototype since EventEmitter is the base for mysql2@<=3.11.4
+  if (
+    typeof basePrototype?.query === 'function' &&
+    typeof basePrototype?.execute === 'function'
+  ) {
+    return basePrototype;
+  }
+
+  // otherwise instrument the connection directly.
+  return connectionPrototype;
+}

plugins/node/opentelemetry-instrumentation-mysql2/src/utils.ts

@@ -223,10 +223,14 @@ describe('mysql2', () => {
         });
 
         query.on('end', () => {
-          assert.strictEqual(rows, 1);
-          const spans = memoryExporter.getFinishedSpans();
-          assert.strictEqual(spans.length, 1);
-          assertSpan(spans[0], sql);
+          try {
+            assert.strictEqual(rows, 1);
+            const spans = memoryExporter.getFinishedSpans();
+            assert.strictEqual(spans.length, 1);
+            assertSpan(spans[0], sql);
+          } catch (e) {
+            done(e);
+          }
           done();
         });
       });
@@ -340,8 +344,12 @@ describe('mysql2', () => {
           const spans = memoryExporter.getFinishedSpans();
           assert.strictEqual(spans.length, 1);
           getLastQueries(1).then(([query]) => {
-            assert.doesNotMatch(query, /.*traceparent.*/);
-            done();
+            try {
+              assert.doesNotMatch(query, /.*traceparent.*/);
+              done();
+            } catch (e) {
+              done(e);
+            }
           });
         });
       });