Fix an issue when the error is nil but is different than nil

Signed-off-by: Bogdan Drutu <[email protected]>

Author: bogdandrutu

receiver/receiverhelper/obsreport.go

@@ -7,6 +7,7 @@ package receiverhelper // import "go.opentelemetry.io/collector/receiver/receive
 
 import (
 	"context"
+	"reflect"
 
 	"go.opentelemetry.io/otel/attribute"
 	"go.opentelemetry.io/otel/codes"
@@ -186,7 +187,7 @@ func (rec *ObsReport) endOp(
 			attribute.Int64(acceptedItemsKey, int64(numAccepted)),
 			attribute.Int64(refusedItemsKey, int64(numRefused)),
 		)
-		if err != nil {
+		if !isErrorNil(err) {
 			span.SetStatus(codes.Error, err.Error())
 		}
 	}
@@ -210,3 +211,12 @@ func (rec *ObsReport) recordMetrics(receiverCtx context.Context, signal pipeline
 	acceptedMeasure.Add(receiverCtx, int64(numAccepted), metric.WithAttributes(rec.otelAttrs...))
 	refusedMeasure.Add(receiverCtx, int64(numRefused), metric.WithAttributes(rec.otelAttrs...))
 }
+
+// Correctly checks for nil, even in case of https://go.dev/doc/faq#nil_error.
+func isErrorNil(err error) bool {
+	if err == nil {
+		return true
+	}
+	val := reflect.ValueOf(err)
+	return val.Kind() == reflect.Ptr && val.IsNil()
+}

receiver/receiverhelper/obsreport_test.go

@@ -296,10 +296,32 @@ func TestCheckReceiverLogsViews(t *testing.T) {
 	assert.Error(t, tt.CheckReceiverLogs(transport, 0, 7))
 }
 
+type myError struct {
+	error
+}
+
+func returnsError(b bool) error {
+	var p *myError
+	if b {
+		p = &myError{error: errors.New("my error")}
+	}
+	return p // Will always return a non-nil error.
+}
+
+func TestIsErrorNil(t *testing.T) {
+	assert.True(t, isErrorNil(nil))
+	assert.False(t, isErrorNil(returnsError(true)))
+	// nolint
+	assert.NotNil(t, returnsError(true) == nil)
+	assert.True(t, isErrorNil(returnsError(false)))
+	// nolint
+	assert.False(t, returnsError(false) == nil)
+	assert.False(t, isErrorNil(myError{error: errors.New("my error")}))
+}
+
 func testTelemetry(t *testing.T, id component.ID, testFunc func(t *testing.T, tt componenttest.TestTelemetry)) {
 	tt, err := componenttest.SetupTelemetry(id)
 	require.NoError(t, err)
 	t.Cleanup(func() { require.NoError(t, tt.Shutdown(context.Background())) })
-
 	testFunc(t, tt)
 }