init post-service

services/post-service/internal/errors.go

@@ -0,0 +1,80 @@
+package internal
+
+import (
+	"fmt"
+
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
+)
+
+func NewServiceError(code ErrorCode, msg string) error {
+	return &ServiceError{
+		code: code,
+		msg: msg,
+	}
+}
+
+func NewServiceErrorf(code ErrorCode, msg string, args ...interface{}) error {
+	return NewServiceError(code, fmt.Sprintf(msg, args...))
+}
+
+func WrapServiceError(original_err error, code ErrorCode, msg string) error {
+	return &ServiceError{
+		code: code,
+		msg: msg,
+		original_err: original_err,
+	}
+}
+
+type ErrorCode int32
+
+const (
+	UnknownErrorCode ErrorCode = iota
+	NotFoundErrorCode
+	ConflictErrorCode
+	ForbiddenErrorCode
+	InvalidArgumentErrorCode
+	ConnectionErrorCode
+)
+
+func (c ErrorCode) GRPCCode() codes.Code {
+	codeMap := map[ErrorCode]codes.Code{
+		UnknownErrorCode: codes.Unknown,
+		NotFoundErrorCode: codes.NotFound,
+		ConflictErrorCode: codes.AlreadyExists,
+		ForbiddenErrorCode: codes.PermissionDenied,
+		InvalidArgumentErrorCode: codes.InvalidArgument,
+		ConnectionErrorCode: codes.Unavailable,
+	}
+
+	grpcCode, mapped := codeMap[c]
+	if mapped {
+		return grpcCode
+	}
+	return codes.Unknown
+}
+
+type ServiceError struct {
+	code ErrorCode
+	msg string
+	original_err error
+}
+
+func (e ServiceError) Error() string {
+	if e.original_err != nil {
+		return fmt.Sprintf("%s: %s", e.msg, e.original_err.Error())
+	}
+	return e.msg
+}
+
+func (e ServiceError) Code() ErrorCode {
+	return e.code
+}
+
+func (e ServiceError) GRPCStatus() *status.Status {
+	return status.New(e.Code().GRPCCode(), e.msg)
+}
+
+func (e ServiceError) Unwrap() error {
+	return e.original_err
+}