cleaned up code formatting and some doc comments per PR review

Author: basvanbeek

endpoint/endpoint.go

@@ -27,16 +27,14 @@ func Chain(outer Middleware, others ...Middleware) Middleware {
 	}
 }
 
-// Failer is an interface that should be implemented by response types that
-// hold error properties as to separate business errors from transport errors.
-// If the response type can hold business errors it is highly advised to
-// implement Failer.
-// Response encoders can check if responses are Failer, and if so if they've
-// failed encode them using a separate write path based on the error.
-// Endpoint middlewares can test if a response type failed and also act or
-// report upon it.
+// Failer may be implemented by Go kit response types that contain business
+// logic error details. If Failed returns a non-nil error, the Go kit transport
+// layer may interpret this as a business logic error, and may encode it
+// differently than a regular, successful response.
 //
-// The addsvc example shows Failer's intended usage.
+// It's not necessary for your response types to implement Failer, but it may
+// help for more sophisticated use cases. The addsvc example shows how Failer
+// should be used by a complete application.
 type Failer interface {
 	Failed() error
 }

tracing/opencensus/endpoint_test.go

@@ -23,10 +23,10 @@ const (
 )
 
 var (
-	err1 = errors.New("someError")
-	err2 = errors.New("otherError")
-	err3 = errors.New("someBusinessError")
-	err4 = errors.New("otherBusinessError")
+	err1 = errors.New("some error")
+	err2 = errors.New("other error")
+	err3 = errors.New("some business error")
+	err4 = errors.New("other business error")
 )
 
 // compile time assertion

tracing/opencensus/grpc.go

@@ -55,8 +55,7 @@ func GRPCClientTrace(options ...TracerOption) kitgrpc.ClientOption {
 	clientFinalizer := kitgrpc.ClientFinalizer(
 		func(ctx context.Context, err error) {
 			if span := trace.FromContext(ctx); span != nil {
-				s, ok := status.FromError(err)
-				if ok {
+				if s, ok := status.FromError(err); ok {
 					span.SetStatus(trace.Status{Code: int32(s.Code()), Message: s.Message()})
 				} else {
 					span.SetStatus(trace.Status{Code: int32(codes.Unknown), Message: err.Error()})
@@ -70,7 +69,6 @@ func GRPCClientTrace(options ...TracerOption) kitgrpc.ClientOption {
 		clientBefore(c)
 		clientFinalizer(c)
 	}
-
 }
 
 // GRPCServerTrace enables OpenCensus tracing of a Go kit gRPC transport server.
@@ -83,33 +81,33 @@ func GRPCServerTrace(options ...TracerOption) kitgrpc.ServerOption {
 
 	serverBefore := kitgrpc.ServerBefore(
 		func(ctx context.Context, md metadata.MD) context.Context {
-			var (
-				spanContext trace.SpanContext
-				ok          bool
-				name        string
-			)
+			var name string
 
 			if cfg.name != "" {
 				name = cfg.name
 			} else {
-				name, ok = ctx.Value(kitgrpc.ContextKeyRequestMethod).(string)
-				if !ok || name == "" {
+				name, _ = ctx.Value(kitgrpc.ContextKeyRequestMethod).(string)
+				if name == "" {
 					// we can't find the gRPC method. probably the
 					// unaryInterceptor was not wired up.
 					name = "unknown grpc method"
 				}
 			}
 
-			traceContext := md[propagationKey]
+			var (
+				parentContext trace.SpanContext
+				traceContext  = md[propagationKey]
+				ok            bool
+			)
 
 			if len(traceContext) > 0 {
 				traceContextBinary := []byte(traceContext[0])
-				spanContext, ok = propagation.FromBinary(traceContextBinary)
+				parentContext, ok = propagation.FromBinary(traceContextBinary)
 				if ok && !cfg.public {
 					ctx, _ = trace.StartSpanWithRemoteParent(
 						ctx,
 						name,
-						spanContext,
+						parentContext,
 						trace.WithSpanKind(trace.SpanKindServer),
 						trace.WithSampler(cfg.sampler),
 					)
@@ -125,8 +123,8 @@ func GRPCServerTrace(options ...TracerOption) kitgrpc.ServerOption {
 			if ok {
 				span.AddLink(
 					trace.Link{
-						TraceID: spanContext.TraceID,
-						SpanID:  spanContext.SpanID,
+						TraceID: parentContext.TraceID,
+						SpanID:  parentContext.SpanID,
 						Type:    trace.LinkTypeChild,
 					},
 				)
@@ -138,8 +136,7 @@ func GRPCServerTrace(options ...TracerOption) kitgrpc.ServerOption {
 	serverFinalizer := kitgrpc.ServerFinalizer(
 		func(ctx context.Context, err error) {
 			if span := trace.FromContext(ctx); span != nil {
-				s, ok := status.FromError(err)
-				if ok {
+				if s, ok := status.FromError(err); ok {
 					span.SetStatus(trace.Status{Code: int32(s.Code()), Message: s.Message()})
 				} else {
 					span.SetStatus(trace.Status{Code: int32(codes.Internal), Message: err.Error()})

tracing/opencensus/http_test.go

@@ -19,7 +19,7 @@ import (
 	kithttp "github.com/go-kit/kit/transport/http"
 )
 
-func TestHttpClientTrace(t *testing.T) {
+func TestHTTPClientTrace(t *testing.T) {
 	var (
 		err     error
 		rec     = &recordingExporter{}
@@ -38,7 +38,6 @@ func TestHttpClientTrace(t *testing.T) {
 	}
 
 	for _, tr := range traces {
-
 		clientTracer := ockit.HTTPClientTrace(ockit.WithName(tr.name))
 		ep := kithttp.NewClient(
 			"GET",