style: add gosimple linter and gofmt linter (#1242)

.golangci.yml

@@ -9,3 +9,5 @@ linters:
     - revive
     - staticcheck
     - govet
+    - gosimple
+    - gofmt

examples/http/echo/main.go

@@ -10,7 +10,7 @@ import (
 func main() {
 	router := echo.New()
 	router.GET("/home", func(ctx echo.Context) error {
-		return ctx.JSON(200,"Hello echo")
+		return ctx.JSON(200, "Hello echo")
 	})
 
 	httpSrv := http.NewServer(http.Address(":8000"))

examples/i18n/internal/service/greeter.go

@@ -34,9 +34,9 @@ func (s *GreeterService) SayHello(ctx context.Context, in *v1.HelloRequest) (*v1
 	helloMsg, err := localizer.Localize(&i18n.LocalizeConfig{
 		DefaultMessage: &i18n.Message{
 			Description: "sayhello",
-			ID:    "sayHello",
+			ID:          "sayHello",
-			One:   "Hello {{.Name}}",
+			One:         "Hello {{.Name}}",
-			Other: "Hello {{.Name}}",
+			Other:       "Hello {{.Name}}",
 		},
 		TemplateData: map[string]interface{}{
 			"Name": in.Name,

metadata/metadata.go

@@ -47,7 +47,7 @@ func (m Metadata) Set(key string, value string) {
 func (m Metadata) Range(f func(k, v string) bool) {
 	for k, v := range m {
 		ret := f(k, v)
-		if ret == false {
+		if !ret {
 			break
 		}
 	}

transport/http/binding/encode.go

@@ -28,7 +28,7 @@ func EncodeURL(pathTemplate string, msg proto.Message, needQuery bool) string {
 	if reg == nil {
 		return pathTemplate
 	}
-	pathParams := make(map[string]struct{}, 0)
+	pathParams := make(map[string]struct{})
 	path := reg.ReplaceAllStringFunc(pathTemplate, func(in string) string {
 		if len(in) < 4 {
 			return in