Add test to check bsp ignores OnEnd and ForceFlush post Shutdown` (#1772)

* Add test to check bsp ignores OnEnd and ForceFlush post shutdown

* Add to CHANGELOG

* Check for err return value

* Stop test execution if there's error with shutting down bsp

Co-authored-by: Tyler Yahn <MrAlias@users.noreply.github.com>

* Use assert to check there's no error calling bsp.ForceFlush()

Co-authored-by: Tyler Yahn <MrAlias@users.noreply.github.com>

* Import require

* Add error message for assertion on be.len()

Co-authored-by: Tyler Yahn <MrAlias@users.noreply.github.com>

Co-authored-by: Tyler Yahn <MrAlias@users.noreply.github.com>

CHANGELOG.md

@@ -10,6 +10,7 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 
 ### Added
 
+- Adds test to check BatchSpanProcessor ignores `OnEnd` and `ForceFlush` post `Shutdown`. (#1772)
 - Option `ExportTimeout` was added to batch span processor. (#1755)
 - Adds semantic conventions for exceptions. (#1492)
 - Added support for configuring OTLP/HTTP Endpoints, Headers, Compression and Timeout via the Environment Variables. (#1758)

sdk/trace/batch_span_processor_test.go

@@ -23,6 +23,7 @@ import (
 	"time"
 
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 
 	"go.opentelemetry.io/otel/trace"
 
@@ -289,6 +290,31 @@ func TestBatchSpanProcessorShutdown(t *testing.T) {
 	assert.Equal(t, 1, bp.shutdownCount)
 }
 
+func TestBatchSpanProcessorPostShutdown(t *testing.T) {
+	tp := basicTracerProvider(t)
+	be := testBatchExporter{}
+	bsp := sdktrace.NewBatchSpanProcessor(&be)
+
+	tp.RegisterSpanProcessor(bsp)
+	tr := tp.Tracer("Normal")
+
+	generateSpan(t, true, tr, testOption{
+		o: []sdktrace.BatchSpanProcessorOption{
+			sdktrace.WithMaxExportBatchSize(50),
+		},
+		genNumSpans: 60,
+	})
+
+	require.NoError(t, bsp.Shutdown(context.Background()), "shutting down BatchSpanProcessor")
+	lenJustAfterShutdown := be.len()
+
+	_, span := tr.Start(context.Background(), "foo")
+	span.End()
+	assert.NoError(t, bsp.ForceFlush(context.Background()), "force flushing BatchSpanProcessor")
+
+	assert.Equal(t, lenJustAfterShutdown, be.len(), "OnEnd and ForceFlush should have no effect after Shutdown")
+}
+
 func TestBatchSpanProcessorForceFlushSucceeds(t *testing.T) {
 	te := testBatchExporter{}
 	tp := basicTracerProvider(t)