test(instr-express): add test for ESM (#1966)

* maint(instr-express): add test for ESM

* dont use router in express test

Author: JamieDanielson

package-lock.json

@@ -46,6 +46,7 @@
   "devDependencies": {
     "@opentelemetry/api": "^1.3.0",
     "@opentelemetry/context-async-hooks": "^1.8.0",
+    "@opentelemetry/contrib-test-utils": "^0.36.0",
     "@opentelemetry/sdk-trace-base": "^1.8.0",
     "@opentelemetry/sdk-trace-node": "^1.8.0",
     "@types/express": "4.17.18",

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

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-import { SpanStatusCode, context, trace } from '@opentelemetry/api';
+import { SpanStatusCode, context, SpanKind, trace } from '@opentelemetry/api';
 import { NodeTracerProvider } from '@opentelemetry/sdk-trace-node';
 import { AsyncHooksContextManager } from '@opentelemetry/context-async-hooks';
 import {
@@ -26,6 +26,7 @@ import { AttributeNames } from '../src/enums/AttributeNames';
 import { ExpressInstrumentation } from '../src';
 import { createServer, httpRequest, serverWithMiddleware } from './utils';
 import { SemanticAttributes } from '@opentelemetry/semantic-conventions';
+import * as testUtils from '@opentelemetry/contrib-test-utils';
 
 const instrumentation = new ExpressInstrumentation();
 instrumentation.enable();
@@ -493,4 +494,43 @@ describe('ExpressInstrumentation', () => {
       );
     });
   });
+  it('should work with ESM usage', async () => {
+    await testUtils.runTestFixture({
+      cwd: __dirname,
+      argv: ['fixtures/use-express.mjs'],
+      env: {
+        NODE_OPTIONS:
+          '--experimental-loader=@opentelemetry/instrumentation/hook.mjs',
+        NODE_NO_WARNINGS: '1',
+      },
+      checkResult: (err, stdout, stderr) => {
+        assert.ifError(err);
+      },
+      checkCollector: (collector: testUtils.TestCollector) => {
+        // use-express.mjs creates an express app with a 'GET /post/:id' endpoint and
+        // a `simpleMiddleware`, then makes a single 'GET /post/0' request. We
+        // expect to see spans like this:
+        //    span 'GET /post/:id'
+        //     `- span 'middleware - query'
+        //     `- span 'middleware - expressInit'
+        //     `- span 'middleware - simpleMiddleware'
+        //     `- span 'request handler - /post/:id'
+        const spans = collector.sortedSpans;
+        assert.strictEqual(spans[0].name, 'GET /post/:id');
+        assert.strictEqual(spans[0].kind, SpanKind.CLIENT);
+        assert.strictEqual(spans[1].name, 'middleware - query');
+        assert.strictEqual(spans[1].kind, SpanKind.SERVER);
+        assert.strictEqual(spans[1].parentSpanId, spans[0].spanId);
+        assert.strictEqual(spans[2].name, 'middleware - expressInit');
+        assert.strictEqual(spans[2].kind, SpanKind.SERVER);
+        assert.strictEqual(spans[2].parentSpanId, spans[0].spanId);
+        assert.strictEqual(spans[3].name, 'middleware - simpleMiddleware');
+        assert.strictEqual(spans[3].kind, SpanKind.SERVER);
+        assert.strictEqual(spans[3].parentSpanId, spans[0].spanId);
+        assert.strictEqual(spans[4].name, 'request handler - /post/:id');
+        assert.strictEqual(spans[4].kind, SpanKind.SERVER);
+        assert.strictEqual(spans[4].parentSpanId, spans[0].spanId);
+      },
+    });
+  });
 });

plugins/node/opentelemetry-instrumentation-express/test/express.test.ts

@@ -0,0 +1,67 @@
+/*
+ * 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 express from an ES module:
+//    node --experimental-loader=@opentelemetry/instrumentation/hook.mjs use-express.mjs
+
+import { promisify } from 'util';
+import { createTestNodeSdk } from '@opentelemetry/contrib-test-utils';
+
+import { HttpInstrumentation } from '@opentelemetry/instrumentation-http';
+import { ExpressInstrumentation } from '../../build/src/index.js';
+
+const sdk = createTestNodeSdk({
+  serviceName: 'use-express',
+  instrumentations: [
+    new HttpInstrumentation(),
+    new ExpressInstrumentation()
+  ]
+})
+sdk.start();
+
+import express from 'express';
+import * as http from 'http';
+
+const app = express();
+
+app.use(async function simpleMiddleware(req, res, next) {
+  // Wait a short delay to ensure this "middleware - ..." span clearly starts
+  // before the "router - ..." span. The test rely on a start-time-based sort
+  // of the produced spans. If they start in the same millisecond, then tests
+  // can be flaky.
+  await promisify(setTimeout)(10);
+  next();
+});
+
+app.get('/post/:id', (req, res) => {
+  res.send(`Post id: ${req.params.id}`);
+});
+
+const server = http.createServer(app);
+await new Promise(resolve => server.listen(0, resolve));
+const port = server.address().port;
+
+await new Promise(resolve => {
+  http.get(`http://localhost:${port}/post/0`, (res) => {
+    res.resume();
+    res.on('end', () => {
+      resolve();
+    });
+  })
+});
+
+await new Promise(resolve => server.close(resolve));
+await sdk.shutdown();