diff --git a/CHANGELOG.md b/CHANGELOG.md new file mode 100644 index 0000000..ed50a14 --- /dev/null +++ b/CHANGELOG.md @@ -0,0 +1,17 @@ +# Changelog + +## [0.1.0] - 2024-01-22 + +🎉 Initial release + +### Added + +- HandlerWithError + + HandlerWithErrorWrapper +- ErrorMiddleware + + Option + * Transformer + - WithTransformer + - WithDefaultTransformer + * LoggerFunc + - WithLogger diff --git a/README.md b/README.md index bda4b06..7c11c88 100644 --- a/README.md +++ b/README.md @@ -1,3 +1,87 @@ # Gin Error Handler A Gin middleware and wrapper functions to make handling errors easier. + +## Installation + +Use the module in the usual way: `codeberg.org/danjones000/gin-error-handler`. + +## Usage + +```go +package main + +import ( + "net/http" + handler "codeberg.org/danjones000/gin-error-handler" + rErrors "codeberg.org/danjones000/responsable-errors" + "github.com/go-playground/validator/v10" + "github.com/gin-gonic/gin" +) + +var _ rErrors.ResponsableError = new(vError) + +type vError struct { + validator.ValidationErrors +} + +func (ve *vError) Msg() string { + return "Validation Error" +} + +func (ve *vError) Status() int { + return http.StatusBadRequest +} + +func (ve *vError) JSON() any { + errs := make([]map[string]string, len(ve)) + for i, fe := range ve { + errs[i] = map[string]string{"field":fe.Field(),"error":fe.Error()} + } + return map[string][]map[string]string{"errors":errs} +} + +func (ve *vError) MarshalJSON() ([]byte, error) { + return json.Marshal(e.JSON()) +} + +func (ve *vError) Unwrap() error { + return ve.ValidationErrors +} + +func main() { + r := gin.New() + r.Use(handler.ErrorMiddleware( + handler.WithTransformer(func (err error) rErrors.ResponsableError { + var ve validator.ValidationErrors + if !errors.As(err, &ve) { + return nil + } + return &vError{ve} + }), + handler.WithDefaultTransformer(), + handler.WithLogger(ctx context.Context, err rErrors.ResponsableError) { + log.Print(err) + }) + + r.GET("/user", handler.HandlerWithErrorWrapper(func (c *gin.Context) error { + var qu struct { + id int `binding:"required"` + }{} + if err := c.ShouldBindQuery(&qu); err != nil { + return err + } + user, err := user.Get(qu.id) + if err != nil { + return err + } + if user == nil { + return rErrors.NewNotFound("User not found") + } + + c.JSON(200, user) + })) +} +``` + +In our example, if `ShouldBindQuery` fails validation, we'll return a nicely formatted error with each validation error, due to our custom transformer. If no user is found, we'll return a 404, with an error message. And any errors are logged to stdout.