✨ Add options, mostly transformers

middleware.go

@@ -7,7 +7,16 @@ import (
 	"github.com/gin-gonic/gin"
 )
 
-func ErrorMiddleware() gin.HandlerFunc {
+func ErrorMiddleware(opts ...Option) gin.HandlerFunc {
+	conf := config{}
+	for _, opt := range opts {
+		conf = opt(conf)
+	}
+
+	if len(conf.transformers) == 0 {
+		conf.transformers = []Transformer{ginTransformer}
+	}
+
 	return func(c *gin.Context) {
 		c.Next()
 		err := c.Errors.Last()
@@ -16,24 +25,27 @@ func ErrorMiddleware() gin.HandlerFunc {
 		}
 
 		var re rErrors.ResponsableError
+
 		errors.As(err, &re)
+		// If we have at least one that's a ResponsableError, we should use it
 		for _, err = range c.Errors {
-			errors.As(err, &re)
 			if re != nil {
 				break
 			}
+			errors.As(err, &re)
 		}
 
-		// @todo we need to add some way to do custom handling
-
-		// @todo Refactor this with 👆
-		if re == nil {
-			switch err.Type {
-			case gin.ErrorTypePrivate:
-				re = rErrors.NewInternalError("%w", err)
-			default:
-				re = rErrors.NewBadRequest("%w", err)
+		// Next, let's check our transformers
+		for _, trans := range conf.transformers {
+			if re != nil {
+				break
 			}
+			re = trans(err)
+		}
+
+		// Still couldn't find one, so it's a 500
+		if re == nil {
+			re = rErrors.NewInternalError("%w", err)
 		}
 
 		c.JSON(re.Status(), re)

middleware_test.go

@@ -43,6 +43,10 @@ func (s *MiddlewareTestSuite) do(err ...error) {
 
 func (s *MiddlewareTestSuite) doParse(err ...error) map[string]any {
 	s.do(err...)
+	return s.parse()
+}
+
+func (s *MiddlewareTestSuite) parse() map[string]any {
 	var out map[string]any
 	jsonErr := json.Unmarshal(s.w.Body.Bytes(), &out)
 	s.Assert().Nil(jsonErr)
@@ -98,3 +102,18 @@ func (s *MiddlewareTestSuite) TestOtherError() {
 	s.Assert().Equal("Unknown Error", outMsg)
 	s.Assert().Equal(http.StatusInternalServerError, s.w.Code)
 }
+
+func (s *MiddlewareTestSuite) TestNoWorkingTransformer() {
+	var noop Transformer = func(err error) rErrors.ResponsableError {
+		return nil
+	}
+	err := errors.New("Foo")
+	s.ctx.Error(err)
+	ErrorMiddleware(WithTransformer(noop))(s.ctx)
+
+	out := s.parse()
+	outMsg, ok := out["error"].(string)
+	s.Assert().True(ok)
+	s.Assert().Equal("Unknown Error", outMsg)
+	s.Assert().Equal(http.StatusInternalServerError, s.w.Code)
+}

options.go

@@ -0,0 +1,41 @@
+package handler
+
+import (
+	"errors"
+
+	rErrors "codeberg.org/danjones000/responsable-errors"
+	"github.com/gin-gonic/gin"
+)
+
+type config struct {
+	transformers []Transformer
+}
+
+type Transformer func(error) rErrors.ResponsableError
+
+type Option func(config) config
+
+func WithTransformer(tr Transformer) Option {
+	return func(c config) config {
+		c.transformers = append(c.transformers, tr)
+		return c
+	}
+}
+
+func WithDefaultTransformer() Option {
+	return WithTransformer(ginTransformer)
+}
+
+func ginTransformer(er error) rErrors.ResponsableError {
+	var err *gin.Error
+	if !errors.As(er, &err) {
+		return nil
+	}
+
+	switch err.Type {
+	case gin.ErrorTypePrivate:
+		return rErrors.NewInternalError("%w", err)
+	default:
+		return rErrors.NewBadRequest("%w", err)
+	}
+}

options_test.go

@@ -0,0 +1,38 @@
+package handler
+
+import (
+	"errors"
+	"fmt"
+	"testing"
+
+	rErrors "codeberg.org/danjones000/responsable-errors"
+	"github.com/stretchr/testify/assert"
+)
+
+var someErr error = errors.New("I am a teapot")
+
+var noop Transformer = func(err error) rErrors.ResponsableError {
+	return nil
+}
+
+func TestWithTrans(t *testing.T) {
+	c := config{}
+	c = WithTransformer(noop)(c)
+	assert.Len(t, c.transformers, 1)
+	exp := fmt.Sprintf("%p", noop)
+	fd := fmt.Sprintf("%p", c.transformers[0])
+	assert.Equal(t, exp, fd)
+}
+
+func TestWithDef(t *testing.T) {
+	c := config{}
+	c = WithDefaultTransformer()(c)
+	assert.Len(t, c.transformers, 1)
+	exp := fmt.Sprintf("%p", ginTransformer)
+	fd := fmt.Sprintf("%p", c.transformers[0])
+	assert.Equal(t, exp, fd)
+}
+
+func TestGinTransNotGinError(t *testing.T) {
+	assert.Nil(t, ginTransformer(someErr))
+}