add unit tests for GlobalTracer

globaltracer_test.go

@@ -0,0 +1,26 @@
+package opentracing
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestIsGlobalTracerRegisteredDefaultIsFalse(t *testing.T) {
+	if IsGlobalTracerRegistered() {
+		t.Errorf("Should return false when no global tracer is registered.")
+	}
+}
+
+func TestAfterSettingGlobalTracerIsGlobalTracerRegisteredReturnsTrue(t *testing.T) {
+	SetGlobalTracer(NoopTracer{})
+
+	if !IsGlobalTracerRegistered() {
+		t.Errorf("Should return true after a tracer has been registered.")
+	}
+}
+
+func TestDefaultTracerIsNoopTracer(t *testing.T) {
+	if reflect.TypeOf(GlobalTracer()) != reflect.TypeOf(NoopTracer{}) {
+		t.Errorf("Should return false when no global tracer is registered.")
+	}
+}