Merge pull request #1143 from tdakkota/fix/multipart-content-type

fix(gen): set Content-Type for JSON-encoded form parameters

.golangci.yml

@@ -128,7 +128,8 @@ issues:
       text: G114
 
     # We are using quoting algorithm from mime/multipart package. False-positive.
-    - path: http[/\\]multipart_file\.go
+    - path: (http|uri)
+      source: form-data; name="%s"
       linters: [gocritic]
       text: sprintfQuotedString
 

gen/_template/request_encode.tmpl

@@ -139,7 +139,11 @@ func encode{{ $op.Name }}Request(
 	{{- else }}
         {{- errorf "unexpected type: %s" $unaliased }}
 	{{- end }}
-	q := uri.NewQueryEncoder()
+	q := uri.NewFormEncoder(map[string]string{
+		{{- range $param := $type.FormParameters }}{{- if $param.Spec.Content }}
+		{{ quote $param.Spec.Name }}: "application/json; charset=utf-8",
+		{{- end }}{{- end }}
+	})
 	{{- range $param := $type.FormParameters }}
 	{
 		// Encode {{ quote $param.Spec.Name }} form field.

uri/query_encoder.go

@@ -1,14 +1,20 @@
 package uri
 
 import (
+	"fmt"
+	"io"
 	"mime/multipart"
+	"net/textproto"
 	"net/url"
+	"strings"
 
 	"github.com/go-faster/errors"
 )
 
 type QueryEncoder struct {
 	values url.Values
+
+	ct map[string]string
 }
 
 func NewQueryEncoder() *QueryEncoder {
@@ -17,6 +23,13 @@ func NewQueryEncoder() *QueryEncoder {
 	}
 }
 
+func NewFormEncoder(ct map[string]string) *QueryEncoder {
+	return &QueryEncoder{
+		values: make(url.Values),
+		ct:     ct,
+	}
+}
+
 type QueryParameterEncodingConfig struct {
 	Name    string
 	Style   QueryStyle
@@ -48,10 +61,32 @@ func (e *QueryEncoder) Values() url.Values {
 func (e *QueryEncoder) WriteMultipart(w *multipart.Writer) error {
 	for k, values := range e.values {
 		for i, value := range values {
-			if err := w.WriteField(k, value); err != nil {
+			if err := e.writeMultipartField(w, k, value); err != nil {
 				return errors.Wrapf(err, "write %q: [%d]", k, i)
 			}
 		}
 	}
 	return nil
 }
+
+func (e *QueryEncoder) writeMultipartField(w *multipart.Writer, key, value string) error {
+	h := make(textproto.MIMEHeader)
+	h.Set("Content-Disposition",
+		fmt.Sprintf(`form-data; name="%s"`, escapeQuotes(key)))
+	if contentType, ok := e.ct[key]; ok {
+		h.Set("Content-Type", contentType)
+	}
+
+	field, err := w.CreatePart(h)
+	if err != nil {
+		return err
+	}
+	_, err = io.WriteString(field, value)
+	return err
+}
+
+var quoteEscaper = strings.NewReplacer("\\", "\\\\", `"`, "\\\"")
+
+func escapeQuotes(s string) string {
+	return quoteEscaper.Replace(s)
+}