From 2b14af35d804c32cdf01c30bfbea564fe06bd266 Mon Sep 17 00:00:00 2001
From: legendecas <legendecas@gmail.com>
Date: Thu, 7 May 2020 01:42:02 +0800
Subject: [PATCH] fix: multi span processor should flush child span processors
 (#1024)

---
 .../src/MultiSpanProcessor.ts                     |  4 +++-
 .../test/MultiSpanProcessor.test.ts               | 15 +++++++++++++++
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/packages/opentelemetry-tracing/src/MultiSpanProcessor.ts b/packages/opentelemetry-tracing/src/MultiSpanProcessor.ts
index b4d4c9d3fa3..343da23af25 100644
--- a/packages/opentelemetry-tracing/src/MultiSpanProcessor.ts
+++ b/packages/opentelemetry-tracing/src/MultiSpanProcessor.ts
@@ -25,7 +25,9 @@ export class MultiSpanProcessor implements SpanProcessor {
   constructor(private readonly _spanProcessors: SpanProcessor[]) {}
 
   forceFlush(): void {
-    // do nothing as all spans are being exported without waiting
+    for (const spanProcessor of this._spanProcessors) {
+      spanProcessor.forceFlush();
+    }
   }
 
   onStart(span: Span): void {
diff --git a/packages/opentelemetry-tracing/test/MultiSpanProcessor.test.ts b/packages/opentelemetry-tracing/test/MultiSpanProcessor.test.ts
index 62b33fe224a..8b95d68aafd 100644
--- a/packages/opentelemetry-tracing/test/MultiSpanProcessor.test.ts
+++ b/packages/opentelemetry-tracing/test/MultiSpanProcessor.test.ts
@@ -65,4 +65,19 @@ describe('MultiSpanProcessor', () => {
     assert.strictEqual(processor1.spans.length, 0);
     assert.strictEqual(processor1.spans.length, processor2.spans.length);
   });
+
+  it('should force span processors to flush', () => {
+    let flushed = false;
+    const processor: SpanProcessor = {
+      forceFlush: () => {
+        flushed = true;
+      },
+      onStart: span => {},
+      onEnd: span => {},
+      shutdown: () => {},
+    };
+    const multiSpanProcessor = new MultiSpanProcessor([processor]);
+    multiSpanProcessor.forceFlush();
+    assert.ok(flushed);
+  });
 });