feat: add forceFlush-function to the BasicTracerProvider-class

packages/opentelemetry-tracing/src/BasicTracerProvider.ts

@@ -112,6 +112,22 @@ export class BasicTracerProvider implements TracerProvider {
     }
   }
 
+  forceFlush(): Promise<void> {
+    const promises = this._registeredSpanProcessors.map(
+      (spanProcessor: SpanProcessor) => {
+        return spanProcessor.forceFlush();
+      }
+    );
+
+    return Promise.all(promises)
+      .then(() => {
+        return void 0;
+      })
+      .catch(error => {
+        throw error;
+      });
+  }
+
   shutdown() {
     return this.activeSpanProcessor.shutdown();
   }

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

@@ -39,6 +39,7 @@ import { Resource } from '@opentelemetry/resources';
 import * as assert from 'assert';
 import * as sinon from 'sinon';
 import { BasicTracerProvider, Span } from '../src';
+import { NoopSpanProcessor } from '../src/NoopSpanProcessor';
 
 describe('BasicTracerProvider', () => {
   let removeEvent: Function | undefined;
@@ -392,6 +393,55 @@ describe('BasicTracerProvider', () => {
     });
   });
 
+  describe('.forceFlush()', () => {
+    it('should call forceFlush on all registered span processors', done => {
+      const tracerProvider = new BasicTracerProvider();
+      const spanProcessorOne = new NoopSpanProcessor();
+      const spyOne = sinon.spy(spanProcessorOne, 'forceFlush');
+      const spanProcessorTwo = new NoopSpanProcessor();
+      const spyTwo = sinon.spy(spanProcessorTwo, 'forceFlush');
+
+      tracerProvider.addSpanProcessor(spanProcessorOne);
+      tracerProvider.addSpanProcessor(spanProcessorTwo);
+
+      tracerProvider
+        .forceFlush()
+        .then(() => {
+          assert(spyOne.calledOnce);
+          assert(spyTwo.calledOnce);
+          done();
+        })
+        .catch(error => {
+          done(error);
+        });
+    });
+
+    it('should throw error when calling forceFlush on all registered span processors fails', done => {
+      const forceFlushStub = sinon.stub(
+        NoopSpanProcessor.prototype,
+        'forceFlush'
+      );
+      forceFlushStub.returns(Promise.reject('Error'));
+
+      const tracerProvider = new BasicTracerProvider();
+      const spanProcessorOne = new NoopSpanProcessor();
+      const spanProcessorTwo = new NoopSpanProcessor();
+      tracerProvider.addSpanProcessor(spanProcessorOne);
+      tracerProvider.addSpanProcessor(spanProcessorTwo);
+
+      tracerProvider
+        .forceFlush()
+        .then(() => {
+          done(new Error('Successful forceFlush not expected'));
+        })
+        .catch(_error => {
+          forceFlushStub.restore();
+          sinon.assert.calledTwice(forceFlushStub);
+          done();
+        });
+    });
+  });
+
   describe('.bind()', () => {
     it('should bind context with NoopContextManager context manager', done => {
       const tracer = new BasicTracerProvider().getTracer('default');