refactor: log error instead of reject in MultiSpanProcessor#forceFlush

Author: mwear

packages/opentelemetry-tracing/src/MultiSpanProcessor.ts

@@ -14,6 +14,7 @@
  * limitations under the License.
  */
 
+import { globalErrorHandler } from '@opentelemetry/core';
 import { SpanProcessor } from './SpanProcessor';
 import { ReadableSpan } from './export/ReadableSpan';
 
@@ -30,10 +31,17 @@ export class MultiSpanProcessor implements SpanProcessor {
     for (const spanProcessor of this._spanProcessors) {
       promises.push(spanProcessor.forceFlush());
     }
-    return new Promise((resolve, reject) => {
-      Promise.all(promises).then(() => {
-        resolve();
-      }, reject);
+    return new Promise(resolve => {
+      Promise.all(promises)
+        .then(() => {
+          resolve();
+        })
+        .catch(error => {
+          globalErrorHandler(
+            error || new Error('MultiSpanProcessor: forceFlush failed')
+          );
+          resolve();
+        });
     });
   }
 

packages/opentelemetry-tracing/test/MultiSpanProcessor.test.ts

@@ -26,6 +26,8 @@ import {
 import {
   notifyOnGlobalShutdown,
   _invokeGlobalShutdown,
+  setGlobalErrorHandler,
+  loggingErrorHandler,
 } from '@opentelemetry/core';
 import { MultiSpanProcessor } from '../src/MultiSpanProcessor';
 
@@ -229,4 +231,27 @@ describe('MultiSpanProcessor', () => {
       done();
     });
   });
+
+  it('should call globalErrorHandler in forceFlush', async () => {
+    const expectedError = new Error('whoops');
+    const testProcessor = new TestProcessor();
+    const forceFlush = Sinon.stub(testProcessor, 'forceFlush');
+    forceFlush.rejects(expectedError);
+
+    const multiSpanProcessor = new MultiSpanProcessor([testProcessor]);
+    const errorHandlerSpy = Sinon.spy();
+
+    setGlobalErrorHandler(errorHandlerSpy);
+
+    await multiSpanProcessor.forceFlush();
+
+    forceFlush.restore();
+    const [[error]] = errorHandlerSpy.args;
+
+    assert.strictEqual(error, expectedError);
+    assert.strictEqual(errorHandlerSpy.callCount, 1);
+
+    //reset global error handler
+    setGlobalErrorHandler(loggingErrorHandler());
+  });
 });