Add test for BridgeTracer Inject and Extract

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>

bridge/opentracing/bridge_test.go

@@ -0,0 +1,73 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package opentracing
+
+import (
+	"reflect"
+	"testing"
+
+	ot "github.com/opentracing/opentracing-go"
+	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/bridge/opentracing/internal"
+	"go.opentelemetry.io/otel/propagation"
+)
+
+func TestMapCarrier(t *testing.T) {
+	carrier := propagation.MapCarrier{}
+	testBridgeWithCarrier(t, carrier)
+}
+
+func TestHeaderCarrier(t *testing.T) {
+	carrier := propagation.HeaderCarrier{}
+	testBridgeWithCarrier(t, carrier)
+}
+
+func TestOTHTTPHeadersCarrier(t *testing.T) {
+	carrier := ot.HTTPHeadersCarrier{}
+	testBridgeWithCarrier(t, carrier)
+}
+
+func TestOTTextMapCarrier(t *testing.T) {
+	carrier := ot.TextMapCarrier{}
+	testBridgeWithCarrier(t, carrier)
+}
+
+func testBridgeWithCarrier(t *testing.T, carrier interface{}) {
+	mockOtelTracer := internal.NewMockTracer()
+	bridgeTracer, _ := NewTracerPair(mockOtelTracer)
+	otel.SetTextMapPropagator(propagation.TraceContext{})
+
+	span := bridgeTracer.StartSpan("testSpan1")
+	defer span.Finish()
+
+	err := bridgeTracer.Inject(span.Context(), ot.HTTPHeaders, carrier)
+	if err != nil {
+		t.Errorf("Inject error: %s", err)
+	}
+
+	extractedSpanContext, err := bridgeTracer.Extract(ot.HTTPHeaders, carrier)
+	if err != nil {
+		t.Errorf("Extract error: %s", err)
+	}
+
+	// Make a copy of the SpanContext with remote set to true
+	originalSpanContext := span.Context().(*bridgeSpanContext)
+	copySpanContext := *originalSpanContext
+	copySpanContext.otelSpanContext = copySpanContext.otelSpanContext.WithRemote(true)
+	// Now the copy should be equal to the original we passed in.
+	if !reflect.DeepEqual(&copySpanContext, extractedSpanContext) {
+		t.Errorf("Extracted span context does not match: %#v, %#v", span.Context(), extractedSpanContext)
+	}
+}