testtrace.Span tracks and returns its SpanKind. (#987)

* Span tracks and returns its SpanKind.

* Include SpanKind addition in CHANGELOG.

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

CHANGELOG.md

@@ -13,6 +13,7 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 - The Zipkin exporter now has `NewExportPipeline` and `InstallNewPipeline` constructor functions to match the common pattern.
     These function build a new exporter with default SDK options and register the exporter with the `global` package respectively. (#944)
 - Add propagator option for gRPC instrumentation. (#986)
+- The `testtrace` package now tracks the `trace.SpanKind` for each span. (#987)
 
 ### Changed
 

api/trace/testtrace/span.go

@@ -49,6 +49,7 @@ type Span struct {
 	attributes    map[kv.Key]kv.Value
 	events        []Event
 	links         map[trace.SpanContext][]kv.KeyValue
+	spanKind      trace.SpanKind
 }
 
 func (s *Span) Tracer() trace.Tracer {
@@ -262,3 +263,8 @@ func (s *Span) StatusCode() codes.Code {
 func (s *Span) StatusMessage() string {
 	return s.statusMessage
 }
+
+// SpanKind returns the span kind of this span.
+func (s *Span) SpanKind() trace.SpanKind {
+	return s.spanKind
+}

api/trace/testtrace/span_test.go

@@ -607,4 +607,23 @@ func TestSpan(t *testing.T) {
 			})
 		}
 	})
+
+	t.Run("#SpanKind", func(t *testing.T) {
+		tp := testtrace.NewProvider()
+		t.Run("returns the value given at start", func(t *testing.T) {
+			t.Parallel()
+
+			e := matchers.NewExpecter(t)
+
+			tracer := tp.Tracer(t.Name())
+			_, span := tracer.Start(context.Background(), "test",
+				trace.WithSpanKind(trace.SpanKindConsumer))
+
+			subject, ok := span.(*testtrace.Span)
+			e.Expect(ok).ToBeTrue()
+			subject.End()
+
+			e.Expect(subject.SpanKind()).ToEqual(trace.SpanKindConsumer)
+		})
+	})
 }

api/trace/testtrace/tracer.go

@@ -50,6 +50,7 @@ func (t *Tracer) Start(ctx context.Context, name string, opts ...trace.StartOpti
 		startTime:  startTime,
 		attributes: make(map[kv.Key]kv.Value),
 		links:      make(map[trace.SpanContext][]kv.KeyValue),
+		spanKind:   c.SpanKind,
 	}
 
 	if c.NewRoot {