[GIN-001] - Add TOML bining for gin (#3081)

Co-authored-by: GitstartHQ <gitstart@users.noreply.github.com>

README.md

@@ -658,18 +658,18 @@ func main() {
 
 ### Model binding and validation
 
-To bind a request body into a type, use model binding. We currently support binding of JSON, XML, YAML and standard form values (foo=bar&boo=baz).
+To bind a request body into a type, use model binding. We currently support binding of JSON, XML, YAML, TOML and standard form values (foo=bar&boo=baz).
 
 Gin uses [**go-playground/validator/v10**](https://github.com/go-playground/validator) for validation. Check the full docs on tags usage [here](https://godoc.org/github.com/go-playground/validator#hdr-Baked_In_Validators_and_Tags).
 
 Note that you need to set the corresponding binding tag on all fields you want to bind. For example, when binding from JSON, set `json:"fieldname"`.
 
 Also, Gin provides two sets of methods for binding:
 - **Type** - Must bind
-  - **Methods** - `Bind`, `BindJSON`, `BindXML`, `BindQuery`, `BindYAML`, `BindHeader`
+  - **Methods** - `Bind`, `BindJSON`, `BindXML`, `BindQuery`, `BindYAML`, `BindHeader`, `BindTOML`
   - **Behavior** - These methods use `MustBindWith` under the hood. If there is a binding error, the request is aborted with `c.AbortWithError(400, err).SetType(ErrorTypeBind)`. This sets the response status code to 400 and the `Content-Type` header is set to `text/plain; charset=utf-8`. Note that if you try to set the response code after this, it will result in a warning `[GIN-debug] [WARNING] Headers were already written. Wanted to override status code 400 with 422`. If you wish to have greater control over the behavior, consider using the `ShouldBind` equivalent method.
 - **Type** - Should bind
-  - **Methods** - `ShouldBind`, `ShouldBindJSON`, `ShouldBindXML`, `ShouldBindQuery`, `ShouldBindYAML`, `ShouldBindHeader`
+  - **Methods** - `ShouldBind`, `ShouldBindJSON`, `ShouldBindXML`, `ShouldBindQuery`, `ShouldBindYAML`, `ShouldBindHeader`, `ShouldBindTOML`,
   - **Behavior** - These methods use `ShouldBindWith` under the hood. If there is a binding error, the error is returned and it is the developer's responsibility to handle the request and error appropriately.
 
 When using the Bind-method, Gin tries to infer the binder depending on the Content-Type header. If you are sure what you are binding, you can use `MustBindWith` or `ShouldBindWith`.

binding/binding.go

@@ -22,6 +22,7 @@ const (
 	MIMEMSGPACK           = "application/x-msgpack"
 	MIMEMSGPACK2          = "application/msgpack"
 	MIMEYAML              = "application/x-yaml"
+	MIMETOML              = "application/toml"
 )
 
 // Binding describes the interface which needs to be implemented for binding the
@@ -83,6 +84,7 @@ var (
 	YAML          = yamlBinding{}
 	Uri           = uriBinding{}
 	Header        = headerBinding{}
+	TOML          = tomlBinding{}
 )
 
 // Default returns the appropriate Binding instance based on the HTTP method
@@ -103,6 +105,8 @@ func Default(method, contentType string) Binding {
 		return MsgPack
 	case MIMEYAML:
 		return YAML
+	case MIMETOML:
+		return TOML
 	case MIMEMultipartPOSTForm:
 		return FormMultipart
 	default: // case MIMEPOSTForm:

binding/binding_nomsgpack.go

@@ -20,6 +20,7 @@ const (
 	MIMEMultipartPOSTForm = "multipart/form-data"
 	MIMEPROTOBUF          = "application/x-protobuf"
 	MIMEYAML              = "application/x-yaml"
+	MIMETOML              = "application/toml"
 )
 
 // Binding describes the interface which needs to be implemented for binding the
@@ -79,6 +80,7 @@ var (
 	YAML          = yamlBinding{}
 	Uri           = uriBinding{}
 	Header        = headerBinding{}
+	TOML          = tomlBinding{}
 )
 
 // Default returns the appropriate Binding instance based on the HTTP method
@@ -99,6 +101,8 @@ func Default(method, contentType string) Binding {
 		return YAML
 	case MIMEMultipartPOSTForm:
 		return FormMultipart
+	case MIMETOML:
+		return TOML
 	default: // case MIMEPOSTForm:
 		return Form
 	}

binding/binding_test.go

@@ -165,6 +165,9 @@ func TestBindingDefault(t *testing.T) {
 
 	assert.Equal(t, YAML, Default("POST", MIMEYAML))
 	assert.Equal(t, YAML, Default("PUT", MIMEYAML))
+
+	assert.Equal(t, TOML, Default("POST", MIMETOML))
+	assert.Equal(t, TOML, Default("PUT", MIMETOML))
 }
 
 func TestBindingJSONNilBody(t *testing.T) {
@@ -454,6 +457,20 @@ func TestBindingXMLFail(t *testing.T) {
 		"<map><foo>bar<foo></map>", "<map><bar>foo</bar></map>")
 }
 
+func TestBindingTOML(t *testing.T) {
+	testBodyBinding(t,
+		TOML, "toml",
+		"/", "/",
+		`foo="bar"`, `bar="foo"`)
+}
+
+func TestBindingTOMLFail(t *testing.T) {
+	testBodyBindingFail(t,
+		TOML, "toml",
+		"/", "/",
+		`foo=\n"bar"`, `bar="foo"`)
+}
+
 func TestBindingYAML(t *testing.T) {
 	testBodyBinding(t,
 		YAML, "yaml",

binding/toml.go

@@ -0,0 +1,31 @@
+package binding
+
+import (
+	"bytes"
+	"io"
+	"net/http"
+
+	"github.com/pelletier/go-toml/v2"
+)
+
+type tomlBinding struct{}
+
+func (tomlBinding) Name() string {
+	return "toml"
+}
+
+func decodeToml(r io.Reader, obj any) error {
+	decoder := toml.NewDecoder(r)
+	if err := decoder.Decode(obj); err != nil {
+		return err
+	}
+	return decoder.Decode(obj)
+}
+
+func (tomlBinding) Bind(req *http.Request, obj any) error {
+	return decodeToml(req.Body, obj)
+}
+
+func (tomlBinding) BindBody(body []byte, obj any) error {
+	return decodeToml(bytes.NewReader(body), obj)
+}

binding/toml_test.go

@@ -0,0 +1,22 @@
+// Copyright 2022 Gin Core Team. All rights reserved.
+// Use of this source code is governed by a MIT style
+// license that can be found in the LICENSE file.
+
+package binding
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestTOMLBindingBindBody(t *testing.T) {
+	var s struct {
+		Foo string `toml:"foo"`
+	}
+	tomlBody := `foo="FOO"`
+	err := tomlBinding{}.BindBody([]byte(tomlBody), &s)
+	require.NoError(t, err)
+	assert.Equal(t, "FOO", s.Foo)
+}

context.go

@@ -34,6 +34,7 @@ const (
 	MIMEPOSTForm          = binding.MIMEPOSTForm
 	MIMEMultipartPOSTForm = binding.MIMEMultipartPOSTForm
 	MIMEYAML              = binding.MIMEYAML
+	MIMETOML              = binding.MIMETOML
 )
 
 // BodyBytesKey indicates a default body bytes key.
@@ -636,6 +637,11 @@ func (c *Context) BindYAML(obj any) error {
 	return c.MustBindWith(obj, binding.YAML)
 }
 
+// BindTOML is a shortcut for c.MustBindWith(obj, binding.TOML).
+func (c *Context) BindTOML(obj interface{}) error {
+	return c.MustBindWith(obj, binding.TOML)
+}
+
 // BindHeader is a shortcut for c.MustBindWith(obj, binding.Header).
 func (c *Context) BindHeader(obj any) error {
 	return c.MustBindWith(obj, binding.Header)
@@ -694,6 +700,11 @@ func (c *Context) ShouldBindYAML(obj any) error {
 	return c.ShouldBindWith(obj, binding.YAML)
 }
 
+// ShouldBindTOML is a shortcut for c.ShouldBindWith(obj, binding.TOML).
+func (c *Context) ShouldBindTOML(obj interface{}) error {
+	return c.ShouldBindWith(obj, binding.TOML)
+}
+
 // ShouldBindHeader is a shortcut for c.ShouldBindWith(obj, binding.Header).
 func (c *Context) ShouldBindHeader(obj any) error {
 	return c.ShouldBindWith(obj, binding.Header)
@@ -965,6 +976,11 @@ func (c *Context) YAML(code int, obj any) {
 	c.Render(code, render.YAML{Data: obj})
 }
 
+// TOML serializes the given struct as TOML into the response body.
+func (c *Context) TOML(code int, obj interface{}) {
+	c.Render(code, render.TOML{Data: obj})
+}
+
 // ProtoBuf serializes the given struct as ProtoBuf into the response body.
 func (c *Context) ProtoBuf(code int, obj any) {
 	c.Render(code, render.ProtoBuf{Data: obj})
@@ -1069,6 +1085,7 @@ type Negotiate struct {
 	XMLData  any
 	YAMLData any
 	Data     any
+	TOMLData any
 }
 
 // Negotiate calls different Render according to acceptable Accept format.
@@ -1090,6 +1107,10 @@ func (c *Context) Negotiate(code int, config Negotiate) {
 		data := chooseData(config.YAMLData, config.Data)
 		c.YAML(code, data)
 
+	case binding.MIMETOML:
+		data := chooseData(config.TOMLData, config.Data)
+		c.TOML(code, data)
+
 	default:
 		c.AbortWithError(http.StatusNotAcceptable, errors.New("the accepted formats are not offered by the server")) // nolint: errcheck
 	}

context_test.go

@@ -1773,6 +1773,23 @@ func TestContextShouldBindWithYAML(t *testing.T) {
 	assert.Equal(t, 0, w.Body.Len())
 }
 
+func TestContextShouldBindWithTOML(t *testing.T) {
+	w := httptest.NewRecorder()
+	c, _ := CreateTestContext(w)
+
+	c.Request, _ = http.NewRequest("POST", "/", bytes.NewBufferString("foo='bar'\nbar= 'foo'"))
+	c.Request.Header.Add("Content-Type", MIMETOML) // set fake content-type
+
+	var obj struct {
+		Foo string `toml:"foo"`
+		Bar string `toml:"bar"`
+	}
+	assert.NoError(t, c.ShouldBindTOML(&obj))
+	assert.Equal(t, "foo", obj.Bar)
+	assert.Equal(t, "bar", obj.Foo)
+	assert.Equal(t, 0, w.Body.Len())
+}
+
 func TestContextBadAutoShouldBind(t *testing.T) {
 	w := httptest.NewRecorder()
 	c, _ := CreateTestContext(w)

go.mod

@@ -8,6 +8,7 @@ require (
 	github.com/goccy/go-json v0.9.7
 	github.com/json-iterator/go v1.1.12
 	github.com/mattn/go-isatty v0.0.14
+	github.com/pelletier/go-toml/v2 v2.0.0-beta.6
 	github.com/stretchr/testify v1.7.1
 	github.com/ugorji/go/codec v1.2.7
 	golang.org/x/net v0.0.0-20210226172049-e18ecbb05110

go.sum

@@ -36,6 +36,8 @@ github.com/modern-go/concurrent v0.0.0-20180228061459-e0a39a4cb421 h1:ZqeYNhU3OH
 github.com/modern-go/concurrent v0.0.0-20180228061459-e0a39a4cb421/go.mod h1:6dJC0mAP4ikYIbvyc7fijjWJddQyLn8Ig3JB5CqoB9Q=
 github.com/modern-go/reflect2 v1.0.2 h1:xBagoLtFs94CBntxluKeaWgTMpvLxC4ur3nMaC9Gz0M=
 github.com/modern-go/reflect2 v1.0.2/go.mod h1:yWuevngMOJpCy52FWWMvUC8ws7m/LJsjYzDa0/r8luk=
+github.com/pelletier/go-toml/v2 v2.0.0-beta.6 h1:JFNqj2afbbhCqTiyN16D7Tudc/aaDzE2FBDk+VlBQnE=
+github.com/pelletier/go-toml/v2 v2.0.0-beta.6/go.mod h1:ke6xncR3W76Ba8xnVxkrZG0js6Rd2BsQEAYrfgJ6eQA=
 github.com/pkg/diff v0.0.0-20210226163009-20ebb0f2a09e/go.mod h1:pJLUxLENpZxwdsKMEsNbx1VGcRFpLqf3715MtcvvzbA=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
@@ -46,8 +48,10 @@ github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+
 github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
 github.com/stretchr/testify v1.6.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+github.com/stretchr/testify v1.7.1-0.20210427113832-6241f9ab9942/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/stretchr/testify v1.7.1 h1:5TQK59W5E3v0r2duFAb7P95B6hEeOyEnHRa8MjYSMTY=
 github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+github.com/ugorji/go v1.2.7 h1:qYhyWUUd6WbiM+C6JZAUkIJt/1WrjzNHY9+KCIjVqTo=
 github.com/ugorji/go v1.2.7/go.mod h1:nF9osbDWLy6bDVv/Rtoh6QgnvNDpmCalQV5urGCCS6M=
 github.com/ugorji/go/codec v1.2.7 h1:YPXUKf7fYbp/y8xloBqZOw2qaVggbfwMlI8WM3wZUJ0=
 github.com/ugorji/go/codec v1.2.7/go.mod h1:WGN1fab3R1fzQlVQTkfxVtIBhWDRqOviHU95kRgeqEY=

render/render.go

@@ -30,6 +30,7 @@ var (
 	_ Render     = Reader{}
 	_ Render     = AsciiJSON{}
 	_ Render     = ProtoBuf{}
+	_ Render     = TOML{}
 )
 
 func writeContentType(w http.ResponseWriter, value []string) {

render/toml.go

@@ -0,0 +1,32 @@
+package render
+
+import (
+	"net/http"
+
+	"github.com/pelletier/go-toml/v2"
+)
+
+// TOML contains the given interface object.
+type TOML struct {
+	Data any
+}
+
+var TOMLContentType = []string{"application/toml; charset=utf-8"}
+
+// Render (TOML) marshals the given interface object and writes data with custom ContentType.
+func (r TOML) Render(w http.ResponseWriter) error {
+	r.WriteContentType(w)
+
+	bytes, err := toml.Marshal(r.Data)
+	if err != nil {
+		return err
+	}
+
+	_, err = w.Write(bytes)
+	return err
+}
+
+// WriteContentType (TOML) writes TOML ContentType for response.
+func (r TOML) WriteContentType(w http.ResponseWriter) {
+	writeContentType(w, TOMLContentType)
+}