fixup labels

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

opentracing.go

@@ -76,6 +76,8 @@ func (t *otTracer) Start(ctx context.Context, name string, opts ...tracer.SpanOp
 		}
 	}
 
+	sp.AddLabels(options.Labels...)
+
 	return tracer.NewSpanContext(ctx, sp), sp
 }
 
@@ -118,23 +120,29 @@ func (os *otSpan) Tracer() tracer.Tracer {
 }
 
 func (os *otSpan) Finish(opts ...tracer.SpanOption) {
-	if len(os.opts.Labels)%2 != 0 {
-		os.opts.Labels = os.opts.Labels[:len(os.opts.Labels)-1]
+	options := os.opts
+	for _, o := range opts {
+		o(&options)
 	}
-	os.opts.Labels = tracer.UniqLabels(os.opts.Labels)
-	for idx := 0; idx < len(os.opts.Labels); idx += 2 {
-		k, ok := os.opts.Labels[idx].(string)
-		if !ok {
-			continue
+
+	l := len(options.Labels)
+	for idx := 0; idx < l; idx++ {
+		switch lt := options.Labels[idx].(type) {
+		case attribute.KeyValue:
+			os.span.SetTag(string(lt.Key), lt.Value.AsInterface())
+		case string:
+			if l > idx+1 {
+				os.span.SetTag(lt, options.Labels[idx+1])
+				idx++
+			}
 		}
-		v := os.opts.Labels[idx+1]
-		os.span.SetTag(k, v)
 	}
+
 	if os.status == tracer.SpanStatusError {
 		os.span.SetTag("error", true)
 		os.span.LogKV("error", os.statusMsg)
 	}
-	os.span.SetTag("span.kind", os.opts.Kind)
+	os.span.SetTag("span.kind", options.Kind)
 	os.span.Finish()
 }
 
@@ -164,12 +172,13 @@ func (os *otSpan) Kind() tracer.SpanKind {
 
 func (os *otSpan) AddLabels(labels ...interface{}) {
 	l := len(labels)
-	for idx := 0; idx < len(labels); idx++ {
+
+	for idx := 0; idx < l; idx++ {
 		switch lt := labels[idx].(type) {
 		case attribute.KeyValue:
 			os.span.SetTag(string(lt.Key), lt.Value.AsInterface())
 		case string:
-			if l < idx+1 {
+			if l > idx+1 {
 				os.span.SetTag(lt, labels[idx+1])
 				idx++
 			}

opentracing_test.go

@@ -30,3 +30,24 @@ func TestTraceID(t *testing.T) {
 		t.Fatalf("invalid span span id %#+v", v)
 	}
 }
+
+func TestTraceTags(t *testing.T) {
+	md := metadata.New(1)
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	ctx = metadata.NewIncomingContext(ctx, md)
+
+	mtr := mocktracer.New()
+	tr := NewTracer(Tracer(mtr))
+	if err := tr.Init(); err != nil {
+		t.Fatal(err)
+	}
+
+	var sp tracer.Span
+
+	ctx, sp = tr.Start(ctx, "test", tracer.WithSpanLabels("key", "val", "odd"))
+	sp.Finish()
+
+	msp := mtr.FinishedSpans()[0]
+	t.Logf("mock span %#+v", msp.Tags())
+}