Use go-cmp to show the diff for test failures. (#513)

* Use go-cmp to show the diff for test failures.

* Use go-cmp in one more test.

* get before vet

Author: songy23

Makefile

@@ -38,10 +38,10 @@ test:
 	$(GOTEST) $(GOTEST_OPT) $(ALL_PKGS)
 
 .PHONY: travis-ci
-travis-ci: fmt vet lint test-with-cover
+travis-ci: fmt install-go-cmp vet lint test-with-cover
 
 .PHONY: test-with-cover
-test-with-cover: 
+test-with-cover:
 	@echo Verifying that all packages have test files to count in coverage
 	@scripts/check-test-files.sh $(subst github.com/census-instrumentation/opencensus-service/,./,$(ALL_PKGS))
 	@echo pre-compiling tests
@@ -86,6 +86,10 @@ vet:
 install-tools:
 	go get golang.org/x/lint/golint
 
+.PHONY: install-go-cmp
+install-go-cmp:
+	go get -u github.com/google/go-cmp/cmp
+
 .PHONY: agent
 agent:
 	GO111MODULE=on CGO_ENABLED=0 go build -o ./bin/ocagent_$(GOOS) $(BUILD_INFO) ./cmd/ocagent
@@ -112,7 +116,7 @@ docker-agent:
 	COMPONENT=agent $(MAKE) docker-component
 
 .PHONY: docker-collector
-docker-collector: 
+docker-collector:
 	COMPONENT=collector $(MAKE) docker-component
 
 

go.mod

@@ -22,6 +22,7 @@ require (
 	github.com/gogo/googleapis v1.1.0 // indirect
 	github.com/golang/groupcache v0.0.0-20190129154638-5b532d6fd5ef // indirect
 	github.com/golang/protobuf v1.3.1
+	github.com/google/go-cmp v0.2.0
 	github.com/google/gofuzz v0.0.0-20170612174753-24818f796faf // indirect
 	github.com/googleapis/gnostic v0.2.0 // indirect
 	github.com/gophercloud/gophercloud v0.0.0-20190206021053-df38e1611dbe // indirect

receiver/jaegerreceiver/jaeger_agent_test.go

@@ -15,13 +15,13 @@
 package jaegerreceiver
 
 import (
-	"bytes"
 	"context"
 	"fmt"
-	"reflect"
 	"testing"
 	"time"
 
+	"github.com/google/go-cmp/cmp"
+
 	"go.opencensus.io/exporter/jaeger"
 	"go.opencensus.io/trace"
 
@@ -228,10 +228,7 @@ func testJaegerAgent(t *testing.T, agentEndpoint string, receiverConfig *Configu
 		},
 	}
 
-	if !reflect.DeepEqual(got, want) {
-		gj, wj := exportertest.ToJSON(got), exportertest.ToJSON(want)
-		if !bytes.Equal(gj, wj) {
-			t.Errorf("Mismatched responses\nGot:\n\t%v\n\t%s\nWant:\n\t%v\n\t%s", got, gj, want, wj)
-		}
+	if diff := cmp.Diff(got, want); diff != "" {
+		t.Errorf("Mismatched responses\n-Got +Want:\n\t%s", diff)
 	}
 }

receiver/jaegerreceiver/trace_receiver_test.go

@@ -15,13 +15,13 @@
 package jaegerreceiver
 
 import (
-	"bytes"
 	"context"
 	"fmt"
-	"reflect"
 	"testing"
 	"time"
 
+	"github.com/google/go-cmp/cmp"
+
 	"go.opencensus.io/exporter/jaeger"
 	"go.opencensus.io/trace"
 
@@ -212,10 +212,7 @@ func TestReception(t *testing.T) {
 		},
 	}
 
-	if !reflect.DeepEqual(got, want) {
-		gj, wj := exportertest.ToJSON(got), exportertest.ToJSON(want)
-		if !bytes.Equal(gj, wj) {
-			t.Errorf("Mismatches responses\nGot:\n\t%v\n\t%s\nWant:\n\t%v\n\t%s", got, gj, want, wj)
-		}
+	if diff := cmp.Diff(got, want); diff != "" {
+		t.Errorf("Mismatched responses\n-Got +Want:\n\t%s", diff)
 	}
 }