Update vendor (#1560)

vendor/github.com/labstack/echo/v4/json.go

@@ -0,0 +1,31 @@
+package echo
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/http"
+)
+
+// DefaultJSONSerializer implements JSON encoding using encoding/json.
+type DefaultJSONSerializer struct{}
+
+// Serialize converts an interface into a json and writes it to the response.
+// You can optionally use the indent parameter to produce pretty JSONs.
+func (d DefaultJSONSerializer) Serialize(c Context, i interface{}, indent string) error {
+	enc := json.NewEncoder(c.Response())
+	if indent != "" {
+		enc.SetIndent("", indent)
+	}
+	return enc.Encode(i)
+}
+
+// Deserialize reads a JSON from a request body and converts it into an interface.
+func (d DefaultJSONSerializer) Deserialize(c Context, i interface{}) error {
+	err := json.NewDecoder(c.Request().Body).Decode(i)
+	if ute, ok := err.(*json.UnmarshalTypeError); ok {
+		return NewHTTPError(http.StatusBadRequest, fmt.Sprintf("Unmarshal type error: expected=%v, got=%v, field=%v, offset=%v", ute.Type, ute.Value, ute.Field, ute.Offset)).SetInternal(err)
+	} else if se, ok := err.(*json.SyntaxError); ok {
+		return NewHTTPError(http.StatusBadRequest, fmt.Sprintf("Syntax error: offset=%v, error=%v", se.Offset, se.Error())).SetInternal(err)
+	}
+	return err
+}