fix(instrumentation-dataloader): support ESM imports of dataloader module

packages/instrumentation-dataloader/package.json

@@ -48,6 +48,7 @@
   "devDependencies": {
     "@opentelemetry/api": "^1.3.0",
     "@opentelemetry/context-async-hooks": "^2.0.0",
+    "@opentelemetry/contrib-test-utils": "^0.49.0",
     "@opentelemetry/sdk-trace-base": "^2.0.0",
     "@opentelemetry/sdk-trace-node": "^2.0.0",
     "@types/mocha": "10.0.10",

packages/instrumentation-dataloader/src/instrumentation.ts

@@ -44,6 +44,13 @@ type PrimeFn = (typeof Dataloader.prototype)['prime'];
 type ClearFn = (typeof Dataloader.prototype)['clear'];
 type ClearAllFn = (typeof Dataloader.prototype)['clearAll'];
 
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+function extractModuleExports(module: any) {
+  return module[Symbol.toStringTag] === 'Module'
+    ? module.default // ESM
+    : module; // CommonJS
+}
+
 export class DataloaderInstrumentation extends InstrumentationBase<DataloaderInstrumentationConfig> {
   constructor(config: DataloaderInstrumentationConfig = {}) {
     super(PACKAGE_NAME, PACKAGE_VERSION, config);
@@ -54,7 +61,8 @@ export class DataloaderInstrumentation extends InstrumentationBase<DataloaderIns
       new InstrumentationNodeModuleDefinition(
         MODULE_NAME,
         ['>=2.0.0 <3'],
-        dataloader => {
+        module => {
+          const dataloader = extractModuleExports(module);
           this._patchLoad(dataloader.prototype);
           this._patchLoadMany(dataloader.prototype);
           this._patchPrime(dataloader.prototype);
@@ -63,14 +71,15 @@ export class DataloaderInstrumentation extends InstrumentationBase<DataloaderIns
 
           return this._getPatchedConstructor(dataloader);
         },
-        dataloader => {
+        module => {
+          const dataloader = extractModuleExports(module);
           ['load', 'loadMany', 'prime', 'clear', 'clearAll'].forEach(method => {
             if (isWrapped(dataloader.prototype[method])) {
               this._unwrap(dataloader.prototype, method);
             }
           });
         }
-      ) as InstrumentationNodeModuleDefinition,
+      ),
     ];
   }
 

packages/instrumentation-dataloader/test/dataloader.test.ts

@@ -21,6 +21,10 @@ import {
 import { context, SpanKind, SpanStatusCode, trace } from '@opentelemetry/api';
 import { NodeTracerProvider } from '@opentelemetry/sdk-trace-node';
 import { AsyncLocalStorageContextManager } from '@opentelemetry/context-async-hooks';
+import {
+  runTestFixture,
+  TestCollector,
+} from '@opentelemetry/contrib-test-utils';
 
 import { DataloaderInstrumentation } from '../src';
 const instrumentation = new DataloaderInstrumentation();
@@ -641,3 +645,25 @@ describe('DataloaderInstrumentation', () => {
     assert.strictEqual(batchSpan.name, 'dataloader.batch');
   });
 });
+
+describe('ESM usage', () => {
+  it('should work with ESM default import', async function () {
+    await runTestFixture({
+      cwd: __dirname,
+      argv: ['fixtures/use-dataloader-default-import.mjs'],
+      env: {
+        NODE_OPTIONS:
+          '--experimental-loader=@opentelemetry/instrumentation/hook.mjs',
+        NODE_NO_WARNINGS: '1',
+      },
+      checkCollector: (collector: TestCollector) => {
+        const spans = collector.sortedSpans;
+        assert.strictEqual(spans[0].name, 'manual');
+        assert.strictEqual(spans[1].name, 'dataloader.load');
+        assert.strictEqual(spans[1].parentSpanId, spans[0].spanId);
+        assert.strictEqual(spans[2].name, 'dataloader.batch');
+        assert.strictEqual(spans[2].parentSpanId, spans[1].spanId);
+      },
+    });
+  });
+});

packages/instrumentation-dataloader/test/fixtures/use-dataloader-default-import.mjs

@@ -0,0 +1,53 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+// Use dataloader from an ES module:
+//    node --experimental-loader=@opentelemetry/instrumentation/hook.mjs use-dataloader-default-import.mjs
+
+import { trace } from '@opentelemetry/api';
+import { createTestNodeSdk } from '@opentelemetry/contrib-test-utils';
+import * as crypto from 'crypto';
+
+import { DataloaderInstrumentation } from '../../build/src/index.js';
+
+const sdk = createTestNodeSdk({
+  serviceName: 'use-dataloader',
+  instrumentations: [
+    new DataloaderInstrumentation()
+  ]
+})
+sdk.start();
+
+import Dataloader from 'dataloader';
+
+function getMd5HashFromIdx(idx ) {
+  return crypto.createHash('md5').update(String(idx)).digest('hex');
+}
+const dataloader = new Dataloader(
+  async keys =>
+    keys.map((_, idx) => {
+      return getMd5HashFromIdx(idx);
+    }),
+  { cache: true }
+);
+
+const tracer = trace.getTracer();
+await tracer.startActiveSpan('manual', async (span) => {
+  await dataloader.load(1);
+  span.end();
+});
+
+await sdk.shutdown();