Add unit tests for emitting error code/type in tracing

inbound.go

@@ -424,7 +424,7 @@ func (response *InboundCallResponse) doneSending() {
 			if response.systemError {
 				errorType = systemErrorType
 				// if the error is a system error, set the error code in span log
-				span.SetTag("rpc.tchannel.system_error_code", GetSystemErrorCode(response.err))
+				span.SetTag("rpc.tchannel.system_error_code", GetSystemErrorCode(response.err).MetricsKey())
 			}
 			span.SetTag("rpc.tchannel.error_type", errorType)
 		}

inbound_internal_test.go

@@ -0,0 +1,98 @@
+// Copyright (c) 2015 Uber Technologies, Inc.
+
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package tchannel
+
+import (
+	"context"
+	"fmt"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/opentracing/opentracing-go/mocktracer"
+)
+
+type statsReporter struct{}
+
+func (w *statsReporter) IncCounter(name string, tags map[string]string, value int64) {
+}
+
+func (w *statsReporter) UpdateGauge(name string, tags map[string]string, value int64) {
+}
+
+func (w *statsReporter) RecordTimer(name string, tags map[string]string, d time.Duration) {
+}
+
+func TestTracingSpanApplicationError(t *testing.T) {
+
+	tracer := mocktracer.New()
+
+	_, cancel := context.WithCancel(context.TODO())
+
+	callResp := &InboundCallResponse{
+		span: tracer.StartSpan("test"),
+		statsReporter: &statsReporter{},
+		reqResWriter: reqResWriter{
+			err: fmt.Errorf("application"),
+		},
+		applicationError: true,
+		timeNow: time.Now,
+		cancel: cancel,
+	}
+
+	callResp.doneSending()
+
+	parsedSpan := callResp.span.(*mocktracer.MockSpan)
+
+	assert.True(t, parsedSpan.Tag("error").(bool))
+	assert.Nil(t, parsedSpan.Tag("rpc.tchannel.system_error_code"))
+	assert.Equal(t, "application", parsedSpan.Tag("rpc.tchannel.error_type").(string))
+
+}
+
+func TestTracingSpanSystemError(t *testing.T) {
+
+	tracer := mocktracer.New()
+
+	_, cancel := context.WithCancel(context.TODO())
+
+	injectedErr := NewSystemError(ErrCodeBusy, "foo")
+
+	callResp := &InboundCallResponse{
+		span: tracer.StartSpan("test"),
+		statsReporter: &statsReporter{},
+		reqResWriter: reqResWriter{
+			err: injectedErr,
+		},
+		systemError: true,
+		timeNow: time.Now,
+		cancel: cancel,
+	}
+
+	callResp.doneSending()
+
+	parsedSpan := callResp.span.(*mocktracer.MockSpan)
+
+	assert.True(t, parsedSpan.Tag("error").(bool))
+	assert.Equal(t, GetSystemErrorCode(injectedErr).MetricsKey(), parsedSpan.Tag("rpc.tchannel.system_error_code").(string))
+	assert.Equal(t, "system", parsedSpan.Tag("rpc.tchannel.error_type").(string))
+
+}