Add RegisterBodyEncoder (#656)

openapi3filter/req_resp_encoder.go

@@ -16,8 +16,34 @@ func encodeBody(body interface{}, mediaType string) ([]byte, error) {
 	return encoder(body)
 }
 
-type bodyEncoder func(body interface{}) ([]byte, error)
+type BodyEncoder func(body interface{}) ([]byte, error)
 
-var bodyEncoders = map[string]bodyEncoder{
+var bodyEncoders = map[string]BodyEncoder{
 	"application/json": json.Marshal,
 }
+
+func RegisterBodyEncoder(contentType string, encoder BodyEncoder) {
+	if contentType == "" {
+		panic("contentType is empty")
+	}
+	if encoder == nil {
+		panic("encoder is not defined")
+	}
+	bodyEncoders[contentType] = encoder
+}
+
+// This call is not thread-safe: body encoders should not be created/destroyed by multiple goroutines.
+func UnregisterBodyEncoder(contentType string) {
+	if contentType == "" {
+		panic("contentType is empty")
+	}
+	delete(bodyEncoders, contentType)
+}
+
+// RegisteredBodyEncoder returns the registered body encoder for the given content type.
+//
+// If no encoder was registered for the given content type, nil is returned.
+// This call is not thread-safe: body encoders should not be created/destroyed by multiple goroutines.
+func RegisteredBodyEncoder(contentType string) BodyEncoder {
+	return bodyEncoders[contentType]
+}

openapi3filter/req_resp_encoder_test.go

@@ -0,0 +1,43 @@
+package openapi3filter
+
+import (
+	"fmt"
+	"net/http"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestRegisterAndUnregisterBodyEncoder(t *testing.T) {
+	var encoder BodyEncoder
+	encoder = func(body interface{}) (data []byte, err error) {
+		return []byte(strings.Join(body.([]string), ",")), nil
+	}
+	contentType := "text/csv"
+	h := make(http.Header)
+	h.Set(headerCT, contentType)
+
+	originalEncoder := RegisteredBodyEncoder(contentType)
+	require.Nil(t, originalEncoder)
+
+	RegisterBodyEncoder(contentType, encoder)
+	require.Equal(t, fmt.Sprintf("%v", encoder), fmt.Sprintf("%v", RegisteredBodyEncoder(contentType)))
+
+	body := []string{"foo", "bar"}
+	got, err := encodeBody(body, contentType)
+
+	require.NoError(t, err)
+	require.Equal(t, []byte("foo,bar"), got)
+
+	UnregisterBodyEncoder(contentType)
+
+	originalEncoder = RegisteredBodyEncoder(contentType)
+	require.Nil(t, originalEncoder)
+
+	_, err = encodeBody(body, contentType)
+	require.Equal(t, &ParseError{
+		Kind:   KindUnsupportedFormat,
+		Reason: prefixUnsupportedCT + ` "text/csv"`,
+	}, err)
+}