generate error interface

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

main.go

@@ -113,6 +113,11 @@ func (g *Generator) Generate(plugin *protogen.Plugin) error {
 
 	}
 
+	if err = g.writeErrors(plugin); err != nil {
+		plugin.Error(err)
+		return err
+	}
+
 	if err = g.astGenerate(plugin); err != nil {
 		plugin.Error(err)
 		return err

util.go

@@ -792,6 +792,35 @@ func (g *Generator) getGoIdentByXref(xref string) (protogen.GoIdent, error) {
 	return protogen.GoIdent{}, fmt.Errorf("not found")
 }
 
+func (g *Generator) getMessageByXref(xref string) (*protogen.Message, error) {
+	idx := strings.LastIndex(xref, ".")
+	pkg := xref[:idx]
+	msg := xref[idx+1:]
+	for _, file := range g.plugin.Files {
+		if strings.Compare(pkg, *(file.Proto.Package)) != 0 {
+			continue
+		}
+		if pmsg, err := getProtoMessage(file.Messages, msg); err == nil {
+			return pmsg, nil
+		}
+	}
+	return nil, fmt.Errorf("not found")
+}
+
+func getProtoMessage(messages []*protogen.Message, msg string) (*protogen.Message, error) {
+	for _, message := range messages {
+		if strings.Compare(msg, message.GoIdent.GoName) == 0 {
+			return message, nil
+		}
+		if len(message.Messages) > 0 {
+			if pmsg, err := getProtoMessage(message.Messages, msg); err == nil {
+				return pmsg, nil
+			}
+		}
+	}
+	return nil, fmt.Errorf("not found")
+}
+
 func getGoIdentByMessage(messages []*protogen.Message, msg string) (protogen.GoIdent, error) {
 	for _, message := range messages {
 		if strings.Compare(msg, message.GoIdent.GoName) == 0 {
@@ -884,3 +913,101 @@ func (g *Generator) generateServiceEndpoints(gfile *protogen.GeneratedFile, serv
 	gfile.P("}")
 	gfile.P(")")
 }
+
+func (g *Generator) writeErrors(plugin *protogen.Plugin) error {
+	errorsMap := make(map[string]struct{})
+
+	for _, file := range plugin.Files {
+		for _, service := range file.Services {
+			for _, method := range service.Methods {
+				if method.Desc.Options() != nil {
+					if proto.HasExtension(method.Desc.Options(), v2.E_Openapiv2Operation) {
+						opts := proto.GetExtension(method.Desc.Options(), v2.E_Openapiv2Operation)
+						if opts != nil {
+							r := opts.(*v2.Operation)
+							if r.Responses == nil {
+								continue
+							}
+
+							for _, rsp := range r.Responses.ResponseCode {
+								if schema := rsp.Value.GetJsonReference(); schema != nil {
+									xref := schema.XRef
+									if xref[0] == '.' {
+										xref = xref[1:]
+									}
+									errorsMap[xref] = struct{}{}
+								}
+							}
+						}
+					}
+					if proto.HasExtension(method.Desc.Options(), v3.E_Openapiv3Operation) {
+						opts := proto.GetExtension(method.Desc.Options(), v3.E_Openapiv3Operation)
+						if opts != nil {
+							r := opts.(*v3.Operation)
+							if r.Responses == nil {
+								continue
+							}
+							resps := r.Responses.ResponseOrReference
+							if r.Responses.GetDefault() != nil {
+								resps = append(resps, &v3.NamedResponseOrReference{Name: "default", Value: r.Responses.GetDefault()})
+							}
+							for _, rsp := range resps {
+								if schema := rsp.Value.GetReference(); schema != nil {
+									xref := schema.XRef
+									if xref[0] == '.' {
+										xref = xref[1:]
+									}
+									errorsMap[xref] = struct{}{}
+								}
+							}
+						}
+					}
+				}
+			}
+		}
+	}
+
+	var gfile *protogen.GeneratedFile
+	if len(errorsMap) > 0 {
+		gfile = plugin.NewGeneratedFile("micro_errors.pb.go", ".")
+		var packageName string
+
+		for _, file := range plugin.Files {
+			if !file.Generate {
+				continue
+			}
+			if len(file.Services) == 0 {
+				continue
+			}
+			packageName = string(file.GoPackageName)
+			break
+		}
+
+		gfile.P("// Code generated by protoc-gen-go-micro. DO NOT EDIT.")
+		gfile.P("// protoc-gen-go-micro version: " + versionComment)
+		gfile.P()
+		gfile.P("package ", packageName)
+		gfile.P()
+
+		gfile.Import(protojsonPackage)
+
+		gfile.P("var (")
+		gfile.P("marshaler = ", protojsonPackage.Ident("MarshalOptions"), "{}")
+		gfile.P(")")
+	}
+
+	for xref := range errorsMap {
+		msg, err := g.getMessageByXref(xref)
+		if err != nil {
+			return err
+		}
+
+		gfile.P(`func (m *`, msg.GoIdent.GoName, `) Error() string {`)
+		gfile.P(`buf, _ := marshaler.Marshal(m)`)
+		gfile.P("return string(buf)")
+		gfile.P(`}`)
+		// log.Printf("xref %#+v %v\n", msg.GoIdent.GoName, err)
+	}
+
+	return nil
+}

variables.go

@@ -19,6 +19,7 @@ var (
 	microCodecPackage      = protogen.GoImportPath("go.unistack.org/micro-proto/v3/codec")
 	microErrorsPackage     = protogen.GoImportPath("go.unistack.org/micro/v3/errors")
 	grpcPackage            = protogen.GoImportPath("google.golang.org/grpc")
+	protojsonPackage       = protogen.GoImportPath("google.golang.org/protobuf/encoding/protojson")
 	timePackage            = protogen.GoImportPath("time")
 	deprecationComment     = "// Deprecated: Do not use."
 	versionComment         = "v3.10.4"