feat(trace): add concurrent-safe Reset method to SpanRecorder

sdk/trace/tracetest/recorder.go

@@ -69,6 +69,19 @@ func (sr *SpanRecorder) Started() []sdktrace.ReadWriteSpan {
 	return dst
 }
 
+// Reset clears the recorded spans.
+//
+// This method is safe to be called concurrently.
+func (sr *SpanRecorder) Reset() {
+	sr.startedMu.Lock()
+	sr.started = nil
+	sr.startedMu.Unlock()
+
+	sr.endedMu.Lock()
+	defer sr.endedMu.Unlock()
+	sr.ended = nil
+}
+
 // Ended returns a copy of all ended spans that have been recorded.
 //
 // This method is safe to be called concurrently.

sdk/trace/tracetest/recorder_test.go

@@ -112,3 +112,27 @@ func TestStartingConcurrentSafe(t *testing.T) {
 
 	assert.Len(t, sr.Started(), 2)
 }
+
+func TestResetConcurrentSafe(t *testing.T) {
+	sr := NewSpanRecorder()
+	ctx := context.Background()
+
+	runConcurrently(
+		func() { sr.OnStart(ctx, new(rwSpan)) },
+		func() { sr.OnStart(ctx, new(rwSpan)) },
+		func() { sr.OnEnd(new(roSpan)) },
+		func() { sr.OnEnd(new(roSpan)) },
+	)
+
+	assert.Len(t, sr.Started(), 2)
+	assert.Len(t, sr.Ended(), 2)
+
+	runConcurrently(
+		func() { sr.Reset() },
+		func() { sr.Reset() },
+		func() { sr.Reset() },
+	)
+
+	assert.Empty(t, sr.Started())
+	assert.Empty(t, sr.Ended())
+}