fix(koa): End span and record exception when a middleware throws an e…

…xception

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

@@ -131,9 +131,14 @@ export class KoaInstrumentation extends BasePlugin<typeof koa> {
  });
 
  return this._tracer.withSpan(span, async () => {
- const result = await middlewareLayer(context, next);
- span.end();
- return result;
+ try {
+ return await middlewareLayer(context, next);
+ } catch (err) {
+ span.recordException(err);
+ throw err;
+ } finally {
+ span.end();
+ }
  });
  };
  }

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

@@ -22,6 +22,10 @@ import {
  InMemorySpanExporter,
  SimpleSpanProcessor,
 } from '@opentelemetry/tracing';
+import {
+ ExceptionAttribute,
+ ExceptionEventName,
+} from '@opentelemetry/semantic-conventions';
 import * as assert from 'assert';
 import * as koa from 'koa';
 import * as http from 'http';
@@ -106,6 +110,10 @@ describe('Koa Instrumentation - Core Tests', () => {
  ctx.body = `${ctx.method} ${ctx.url} - ${ms}ms`;
  };
 
+ const failingMiddleware: koa.Middleware = async (_ctx, _next) => {
+ throw new Error('I failed!');
+ };
+
  describe('Instrumenting core middleware calls', () => {
  it('should create a child span for middlewares', async () => {
  const rootSpan = tracer.startSpan('rootSpan');
@@ -193,6 +201,40 @@ describe('Koa Instrumentation - Core Tests', () => {
  assert.notStrictEqual(exportedRootSpan, undefined);
  });
  });
+
+ it('should propagate exceptions in the middleware while marking the span with an exception', async () => {
+ const rootSpan = tracer.startSpan('rootSpan');
+ app.use((_ctx, next) => tracer.withSpan(rootSpan, next));
+ app.use(failingMiddleware);
+ const res = await httpRequest.get(`http://localhost:${port}`);
+ assert.deepStrictEqual(res, 'Internal Server Error');
+
+ rootSpan.end();
+ assert.deepStrictEqual(memoryExporter.getFinishedSpans().length, 3);
+
+ const requestHandlerSpan = memoryExporter
+ .getFinishedSpans()
+ .find(span => span.name.includes('failingMiddleware'));
+ assert.notStrictEqual(requestHandlerSpan, undefined);
+
+ assert.strictEqual(
+ requestHandlerSpan?.attributes[AttributeNames.KOA_TYPE],
+ KoaLayerType.MIDDLEWARE
+ );
+ const exportedRootSpan = memoryExporter
+ .getFinishedSpans()
+ .find(span => span.name === 'rootSpan');
+ assert.ok(exportedRootSpan);
+ const exceptionEvent = requestHandlerSpan.events.find(
+ event => event.name === ExceptionEventName
+ );
+ assert.ok(exceptionEvent, 'There should be an exception event recorded');
+ assert.deepStrictEqual(exceptionEvent.name, 'exception');
+ assert.deepStrictEqual(
+ exceptionEvent.attributes![ExceptionAttribute.MESSAGE],
+ 'I failed!'
+ );
+ });
  });
 
  describe('Disabling koa instrumentation', () => {