Add integration tests for span processor ordering (#1208)

- Test by span attributes added by processors in the order
  they were registered.

Signed-off-by: Hui Kang <kangh@us.ibm.com>

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

CHANGELOG.md

@@ -70,6 +70,7 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 - Renamed `SamplingDecision` values to comply with OpenTelemetry specification change. (#1192)
 - Renamed Zipkin attribute names from `ot.status_code & ot.status_description` to `otel.status_code & otel.status_description`. (#1201)
 - The default SDK now invokes registered `SpanProcessor`s in the order they were registered with the `TracerProvider`. (#1195)
+- Add test of spans being processed by the `SpanProcessor`s in the order they were registered. (#1203)
 
 ### Removed
 

sdk/trace/span_processor_test.go

@@ -18,20 +18,32 @@ import (
 	"context"
 	"testing"
 
+	"go.opentelemetry.io/otel/label"
 	export "go.opentelemetry.io/otel/sdk/export/trace"
 )
 
 type testSpanProcesor struct {
+	name          string
 	spansStarted  []*export.SpanData
 	spansEnded    []*export.SpanData
 	shutdownCount int
 }
 
 func (t *testSpanProcesor) OnStart(s *export.SpanData) {
+	kv := label.KeyValue{
+		Key:   "OnStart",
+		Value: label.StringValue(t.name),
+	}
+	s.Attributes = append(s.Attributes, kv)
 	t.spansStarted = append(t.spansStarted, s)
 }
 
 func (t *testSpanProcesor) OnEnd(s *export.SpanData) {
+	kv := label.KeyValue{
+		Key:   "OnEnd",
+		Value: label.StringValue(t.name),
+	}
+	s.Attributes = append(s.Attributes, kv)
 	t.spansEnded = append(t.spansEnded, s)
 }
 
@@ -45,10 +57,8 @@ func (t *testSpanProcesor) ForceFlush() {
 func TestRegisterSpanProcessort(t *testing.T) {
 	name := "Register span processor before span starts"
 	tp := basicTracerProvider(t)
-	sps := []*testSpanProcesor{
-		NewTestSpanProcessor(),
-		NewTestSpanProcessor(),
-	}
+	spNames := []string{"sp1", "sp2", "sp3"}
+	sps := NewNamedTestSpanProcessors(spNames)
 
 	for _, sp := range sps {
 		tp.RegisterSpanProcessor(sp)
@@ -68,16 +78,29 @@ func TestRegisterSpanProcessort(t *testing.T) {
 		if gotCount != wantCount {
 			t.Errorf("%s: ended count: got %d, want %d\n", name, gotCount, wantCount)
 		}
+
+		c := 0
+		for _, kv := range sp.spansStarted[0].Attributes {
+			if kv.Key != "OnStart" {
+				continue
+			}
+			gotValue := kv.Value.AsString()
+			if gotValue != spNames[c] {
+				t.Errorf("%s: ordered attributes: got %s, want %s\n", name, gotValue, spNames[c])
+			}
+			c++
+		}
+		if c != len(spNames) {
+			t.Errorf("%s: expected attributes(OnStart): got %d, want %d\n", name, c, len(spNames))
+		}
 	}
 }
 
 func TestUnregisterSpanProcessor(t *testing.T) {
 	name := "Start span after unregistering span processor"
 	tp := basicTracerProvider(t)
-	sps := []*testSpanProcesor{
-		NewTestSpanProcessor(),
-		NewTestSpanProcessor(),
-	}
+	spNames := []string{"sp1", "sp2", "sp3"}
+	sps := NewNamedTestSpanProcessors(spNames)
 
 	for _, sp := range sps {
 		tp.RegisterSpanProcessor(sp)
@@ -105,13 +128,28 @@ func TestUnregisterSpanProcessor(t *testing.T) {
 		if gotCount != wantCount {
 			t.Errorf("%s: ended count: got %d, want %d\n", name, gotCount, wantCount)
 		}
+
+		c := 0
+		for _, kv := range sp.spansEnded[0].Attributes {
+			if kv.Key != "OnEnd" {
+				continue
+			}
+			gotValue := kv.Value.AsString()
+			if gotValue != spNames[c] {
+				t.Errorf("%s: ordered attributes: got %s, want %s\n", name, gotValue, spNames[c])
+			}
+			c++
+		}
+		if c != len(spNames) {
+			t.Errorf("%s: expected attributes(OnEnd): got %d, want %d\n", name, c, len(spNames))
+		}
 	}
 }
 
 func TestUnregisterSpanProcessorWhileSpanIsActive(t *testing.T) {
 	name := "Unregister span processor while span is active"
 	tp := basicTracerProvider(t)
-	sp := NewTestSpanProcessor()
+	sp := NewTestSpanProcessor("sp")
 	tp.RegisterSpanProcessor(sp)
 
 	tr := tp.Tracer("SpanProcessor")
@@ -136,7 +174,7 @@ func TestUnregisterSpanProcessorWhileSpanIsActive(t *testing.T) {
 func TestSpanProcessorShutdown(t *testing.T) {
 	name := "Increment shutdown counter of a span processor"
 	tp := basicTracerProvider(t)
-	sp := NewTestSpanProcessor()
+	sp := NewTestSpanProcessor("sp")
 	if sp == nil {
 		t.Fatalf("Error creating new instance of TestSpanProcessor\n")
 	}
@@ -154,7 +192,7 @@ func TestSpanProcessorShutdown(t *testing.T) {
 func TestMultipleUnregisterSpanProcessorCalls(t *testing.T) {
 	name := "Increment shutdown counter after first UnregisterSpanProcessor call"
 	tp := basicTracerProvider(t)
-	sp := NewTestSpanProcessor()
+	sp := NewTestSpanProcessor("sp")
 	if sp == nil {
 		t.Fatalf("Error creating new instance of TestSpanProcessor\n")
 	}
@@ -178,6 +216,14 @@ func TestMultipleUnregisterSpanProcessorCalls(t *testing.T) {
 	}
 }
 
-func NewTestSpanProcessor() *testSpanProcesor {
-	return &testSpanProcesor{}
+func NewTestSpanProcessor(name string) *testSpanProcesor {
+	return &testSpanProcesor{name: name}
+}
+
+func NewNamedTestSpanProcessors(names []string) []*testSpanProcesor {
+	tsp := []*testSpanProcesor{}
+	for _, n := range names {
+		tsp = append(tsp, NewTestSpanProcessor(n))
+	}
+	return tsp
 }