fix: unwrap of code (#17)

internal/pkg/multierr/multierr.go

@@ -0,0 +1,6 @@
+package multierr
+
+type MultiError interface {
+	error
+	Unwrap() []error
+}

pkg/v1/grpcerr/grpcerr_generated.go.tmpl

@@ -5,6 +5,7 @@ package grpcerr
 import (
 	"errors"
 
+	"github.com/hedhyw/semerr/internal/pkg/multierr"
 	"github.com/hedhyw/semerr/pkg/v1/semerr"
 
 	"google.golang.org/grpc/codes"
@@ -14,16 +15,39 @@ import (
 // Code returns grpc status code for err. In case of joined errors
 // it returns the first code found in the chain.
 func Code(err error) codes.Code {
-	switch {
-	case err == nil:
+	return codeRecursion(err)
+}
+
+func codeRecursion(err error) codes.Code {
+	switch err.(type) {
+	case nil:
 		return codes.OK
 	{{- range $errorDef := . }}
-	case errors.As(err, &semerr.{{ $errorDef.Name }}{}):
+	case semerr.{{ $errorDef.Name }}:
 		return {{ $errorDef.GRPCStatus }}
 	{{- end }}
-	default:
-		return getGRPCErrorCode(err)
 	}
+
+	grpcCode := getGRPCErrorCode(err)
+	if grpcCode != codes.Unknown {
+		return grpcCode
+	}
+
+	if err := errors.Unwrap(err); err != nil {
+		return codeRecursion(err)
+	}
+
+	if multiErr, ok := err.(multierr.MultiError); ok && multiErr != nil {
+		for _, err := range multiErr.Unwrap() {
+			code := codeRecursion(err)
+
+			if code != codes.Unknown {
+				return code
+			}
+		}
+	}
+
+	return codes.Unknown
 }
 
 func getGRPCErrorCode(err error) codes.Code {

pkg/v1/httperr/httperr_generated.go.tmpl

@@ -6,22 +6,46 @@ import (
 	"errors"
 	"net/http"
 
+	"github.com/hedhyw/semerr/internal/pkg/multierr"
 	"github.com/hedhyw/semerr/pkg/v1/semerr"
 )
 
 // Code returns http status code for err. In case of joined errors
 // it returns the first code found in the chain.
 func Code(err error) int {
-	switch {
-	case err == nil:
+	code := codeRecursion(err)
+	if code == 0 {
+		return http.StatusInternalServerError
+	}
+
+	return code
+}
+
+func codeRecursion(err error) int {
+	switch err.(type) {
+	case nil:
 		return http.StatusOK
 	{{- range $errorDef := . }}
-	case errors.As(err, &semerr.{{ $errorDef.Name }}{}):
+	case semerr.{{ $errorDef.Name }}:
 		return {{ $errorDef.HTTPStatus }}
 	{{- end }}
-	default:
-		return http.StatusInternalServerError
 	}
+
+	if err := errors.Unwrap(err); err != nil {
+		return codeRecursion(err)
+	}
+
+	if multiErr, ok := err.(multierr.MultiError); ok && multiErr != nil {
+		for _, err := range multiErr.Unwrap() {
+			code := codeRecursion(err)
+
+			if code != 0 {
+				return code
+			}
+		}
+	}
+
+	return 0
 }
 
 // Wrap wraps the `err` with an error corresponding to the `code`.