refactor(binding): separate the common logic and msgpack-specific implementation

binding/binding.go

@@ -2,8 +2,6 @@
 // Use of this source code is governed by a MIT style
 // license that can be found in the LICENSE file.
 
-//go:build !nomsgpack
-
 package binding
 
 import "net/http"
@@ -18,8 +16,6 @@ const (
 	MIMEPOSTForm          = "application/x-www-form-urlencoded"
 	MIMEMultipartPOSTForm = "multipart/form-data"
 	MIMEPROTOBUF          = "application/x-protobuf"
-	MIMEMSGPACK           = "application/x-msgpack"
-	MIMEMSGPACK2          = "application/msgpack"
 	MIMEYAML              = "application/x-yaml"
 	MIMEYAML2             = "application/yaml"
 	MIMETOML              = "application/toml"
@@ -80,7 +76,6 @@ var (
 	FormPost      Binding     = formPostBinding{}
 	FormMultipart Binding     = formMultipartBinding{}
 	ProtoBuf      BindingBody = protobufBinding{}
-	MsgPack       BindingBody = msgpackBinding{}
 	YAML          BindingBody = yamlBinding{}
 	Uri           BindingUri  = uriBinding{}
 	Header        Binding     = headerBinding{}
@@ -88,33 +83,6 @@ var (
 	TOML          BindingBody = tomlBinding{}
 )
 
-// Default returns the appropriate Binding instance based on the HTTP method
-// and the content type.
-func Default(method, contentType string) Binding {
-	if method == http.MethodGet {
-		return Form
-	}
-
-	switch contentType {
-	case MIMEJSON:
-		return JSON
-	case MIMEXML, MIMEXML2:
-		return XML
-	case MIMEPROTOBUF:
-		return ProtoBuf
-	case MIMEMSGPACK, MIMEMSGPACK2:
-		return MsgPack
-	case MIMEYAML, MIMEYAML2:
-		return YAML
-	case MIMETOML:
-		return TOML
-	case MIMEMultipartPOSTForm:
-		return FormMultipart
-	default: // case MIMEPOSTForm:
-		return Form
-	}
-}
-
 func validate(obj any) error {
 	if Validator == nil {
 		return nil

binding/binding_msgpack.go

@@ -0,0 +1,46 @@
+// Copyright 2025 Manu Martinez-Almeida. All rights reserved.
+// Use of this source code is governed by a MIT style
+// license that can be found in the LICENSE file.
+
+//go:build !nomsgpack
+
+package binding
+
+import "net/http"
+
+// Content-Type MIME of msgpack.
+const (
+	MIMEMSGPACK  = "application/x-msgpack"
+	MIMEMSGPACK2 = "application/msgpack"
+)
+
+// MsgPack implement the BindingBody interface.
+var MsgPack BindingBody = msgpackBinding{}
+
+// Default returns the appropriate Binding instance based on the HTTP method
+// and the content type.
+func Default(method, contentType string) Binding {
+	if method == http.MethodGet {
+		return Form
+	}
+
+	switch contentType {
+	case MIMEMSGPACK, MIMEMSGPACK2:
+		return MsgPack
+
+	case MIMEJSON:
+		return JSON
+	case MIMEXML, MIMEXML2:
+		return XML
+	case MIMEPROTOBUF:
+		return ProtoBuf
+	case MIMEYAML, MIMEYAML2:
+		return YAML
+	case MIMETOML:
+		return TOML
+	case MIMEMultipartPOSTForm:
+		return FormMultipart
+	default: // case MIMEPOSTForm:
+		return Form
+	}
+}

binding/binding_nomsgpack.go

@@ -8,86 +8,10 @@ package binding
 
 import "net/http"
 
-// Content-Type MIME of the most common data formats.
-const (
-	MIMEJSON              = "application/json"
-	MIMEHTML              = "text/html"
-	MIMEXML               = "application/xml"
-	MIMEXML2              = "text/xml"
-	MIMEPlain             = "text/plain"
-	MIMEPOSTForm          = "application/x-www-form-urlencoded"
-	MIMEMultipartPOSTForm = "multipart/form-data"
-	MIMEPROTOBUF          = "application/x-protobuf"
-	MIMEYAML              = "application/x-yaml"
-	MIMEYAML2             = "application/yaml"
-	MIMETOML              = "application/toml"
-)
-
-// Binding describes the interface which needs to be implemented for binding the
-// data present in the request such as JSON request body, query parameters or
-// the form POST.
-type Binding interface {
-	Name() string
-	Bind(*http.Request, any) error
-}
-
-// BindingBody adds BindBody method to Binding. BindBody is similar with Bind,
-// but it reads the body from supplied bytes instead of req.Body.
-type BindingBody interface {
-	Binding
-	BindBody([]byte, any) error
-}
-
-// BindingUri adds BindUri method to Binding. BindUri is similar with Bind,
-// but it reads the Params.
-type BindingUri interface {
-	Name() string
-	BindUri(map[string][]string, any) error
-}
-
-// StructValidator is the minimal interface which needs to be implemented in
-// order for it to be used as the validator engine for ensuring the correctness
-// of the request. Gin provides a default implementation for this using
-// https://github.com/go-playground/validator/tree/v10.6.1.
-type StructValidator interface {
-	// ValidateStruct can receive any kind of type and it should never panic, even if the configuration is not right.
-	// If the received type is not a struct, any validation should be skipped and nil must be returned.
-	// If the received type is a struct or pointer to a struct, the validation should be performed.
-	// If the struct is not valid or the validation itself fails, a descriptive error should be returned.
-	// Otherwise nil must be returned.
-	ValidateStruct(any) error
-
-	// Engine returns the underlying validator engine which powers the
-	// StructValidator implementation.
-	Engine() any
-}
-
-// Validator is the default validator which implements the StructValidator
-// interface. It uses https://github.com/go-playground/validator/tree/v10.6.1
-// under the hood.
-var Validator StructValidator = &defaultValidator{}
-
-// These implement the Binding interface and can be used to bind the data
-// present in the request to struct instances.
-var (
-	JSON          = jsonBinding{}
-	XML           = xmlBinding{}
-	Form          = formBinding{}
-	Query         = queryBinding{}
-	FormPost      = formPostBinding{}
-	FormMultipart = formMultipartBinding{}
-	ProtoBuf      = protobufBinding{}
-	YAML          = yamlBinding{}
-	Uri           = uriBinding{}
-	Header        = headerBinding{}
-	TOML          = tomlBinding{}
-	Plain         = plainBinding{}
-)
-
 // Default returns the appropriate Binding instance based on the HTTP method
 // and the content type.
 func Default(method, contentType string) Binding {
-	if method == "GET" {
+	if method == http.MethodGet {
 		return Form
 	}
 
@@ -100,18 +24,11 @@ func Default(method, contentType string) Binding {
 		return ProtoBuf
 	case MIMEYAML, MIMEYAML2:
 		return YAML
-	case MIMEMultipartPOSTForm:
-		return FormMultipart
 	case MIMETOML:
 		return TOML
+	case MIMEMultipartPOSTForm:
+		return FormMultipart
 	default: // case MIMEPOSTForm:
 		return Form
 	}
 }
-
-func validate(obj any) error {
-	if Validator == nil {
-		return nil
-	}
-	return Validator.ValidateStruct(obj)
-}