Meeting simongottschlag comments on #252.

Author: Anders Qvist

README.md

@@ -323,19 +323,30 @@ It is possible to add a custom function to handle errors. The error handler can
 
 ```go
 type Message struct {
-  Message string `json:"message"`
-	Url string `json:"url"`
+	Message string `json:"message"`
+	Url     string `json:"url"`
 }
 
-errorHandler := func(ctx context.Context, request *OidcError) *Response {
-	message := Message {
-		Message: request.status,
-		Url: request.Url,
+func errorHandler(ctx context.Context, oidcErr *options.OidcError) *options.Response {
+	message := Message{
+		Message: string(oidcErr.Status),
+		Url:     oidcErr.Url.String(),
 	}
-	json, _ := json.Marshal(message)
-	return &options.Response {
-		Status: 418,
-		Body: json,
+	var headers map[string]string
+	json, err := json.Marshal(message)
+	if err != nil {
+		headers["Content-Type"] = "text/plain"
+		return &options.Response{
+			StatusCode: 500,
+			Headers:    headers,
+			Body:       []byte("Internal encoding failure\r\n"),
+		}
+	}
+	headers["Content-Type"] = "text/plain"
+	return &options.Response{
+		StatusCode: 418,
+		Headers:    headers,
+		Body:       json,
 	}
 }
 
@@ -347,6 +358,8 @@ oidcHandler := oidcgin.New(
 )
 ```
 
+This error handling interface was changed in v0.0.42. The previous interface was `func(description ErrorDescription, err error)`. In order to retain the same behavior, you need to update your error handler to read `desctiption` and `err` from `oidcErr` and return `nil`.
+
 ### Testing with the middleware enabled
 
 There's a small package that simulates an OpenID Provider that can be used with tests.

internal/oidctesting/tests.go

@@ -321,14 +321,14 @@ func runTestErrorHandler(t *testing.T, testName string, tester tester) {
 		}{
 			{
 				testDescription:    "no output",
-				errorHandler:       func(ctx context.Context, request *options.OidcError) *options.Response { return nil },
+				errorHandler:       func(ctx context.Context, oidcErr *options.OidcError) *options.Response { return nil },
 				expectStatusCode:   http.StatusBadRequest,
 				expectHeaders:      map[string]string{},
 				expectBodyContains: []byte{},
 			},
 			{
 				testDescription: "basic propagation",
-				errorHandler: func(ctx context.Context, request *options.OidcError) *options.Response {
+				errorHandler: func(ctx context.Context, oidcErr *options.OidcError) *options.Response {
 					return &options.Response{
 						StatusCode: 418,
 						Headers:    map[string]string{},
@@ -343,7 +343,7 @@ func runTestErrorHandler(t *testing.T, testName string, tester tester) {
 			},
 			{
 				testDescription: "additional header",
-				errorHandler: func(ctx context.Context, request *options.OidcError) *options.Response {
+				errorHandler: func(ctx context.Context, oidcErr *options.OidcError) *options.Response {
 					return &options.Response{
 						StatusCode: 418,
 						Headers:    map[string]string{"some": "header"},
@@ -359,7 +359,7 @@ func runTestErrorHandler(t *testing.T, testName string, tester tester) {
 			},
 			{
 				testDescription: "content type",
-				errorHandler: func(ctx context.Context, request *options.OidcError) *options.Response {
+				errorHandler: func(ctx context.Context, oidcErr *options.OidcError) *options.Response {
 					return &options.Response{
 						StatusCode: 418,
 						Headers:    map[string]string{"content-type": "application/json"},

oidcecho/echo.go

@@ -24,13 +24,13 @@ func onError(c echo.Context, errorHandler options.ErrorHandler, statusCode int,
 		c.Logger().Error(err)
 		return c.NoContent(statusCode)
 	}
-	error := options.OidcError{
+	oidcErr := options.OidcError{
 		Url:     c.Request().URL,
 		Headers: c.Request().Header,
 		Status:  description,
 		Error:   err,
 	}
-	response := errorHandler(c.Request().Context(), &error)
+	response := errorHandler(c.Request().Context(), &oidcErr)
 	if response == nil {
 		c.Logger().Error(err)
 		return c.NoContent(statusCode)

oidcfiber/fiber.go

@@ -29,13 +29,13 @@ func onError(c *fiber.Ctx, errorHandler options.ErrorHandler, statusCode int, de
 	for k, v := range c.GetReqHeaders() {
 		headers[k] = []string{v}
 	}
-	error := options.OidcError{
+	oidcErr := options.OidcError{
 		Url:     url,
 		Headers: headers,
 		Status:  description,
 		Error:   err,
 	}
-	response := errorHandler(c.Context(), &error)
+	response := errorHandler(c.Context(), &oidcErr)
 	if response == nil {
 		return c.SendStatus(statusCode)
 	}

oidcgin/gin.go

@@ -25,13 +25,13 @@ func onError(c *gin.Context, errorHandler options.ErrorHandler, statusCode int,
 		return c.AbortWithError(statusCode, err)
 	}
 
-	error := options.OidcError{
+	oidcErr := options.OidcError{
 		Url:     c.Request.URL,
 		Headers: c.Request.Header,
 		Status:  description,
 		Error:   err,
 	}
-	response := errorHandler(c.Request.Context(), &error)
+	response := errorHandler(c.Request.Context(), &oidcErr)
 	if response == nil {
 		return c.AbortWithError(statusCode, err)
 	}

oidchttp/http.go

@@ -25,13 +25,13 @@ func onError(r *http.Request, w http.ResponseWriter, errorHandler options.ErrorH
 		w.WriteHeader(statusCode)
 		return
 	}
-	error := options.OidcError{
+	oidcErr := options.OidcError{
 		Url:     r.URL,
 		Headers: r.Header,
 		Status:  description,
 		Error:   err,
 	}
-	response := errorHandler(r.Context(), &error)
+	response := errorHandler(r.Context(), &oidcErr)
 	if response == nil {
 		w.WriteHeader(statusCode)
 		return

options/options.go

@@ -7,23 +7,22 @@ import (
 	"time"
 )
 
-// Context information for the error handler.
+// OidcError contains context information for the error handler.
 type OidcError struct {
 	Url     *url.URL
 	Headers http.Header
 	Error   error
 	Status  ErrorDescription
 }
 
-// Error handlers are expected to produce an abstract HTTP response that
-// the framework adapter will render.
+// Response holds an abstract HTTP response that the framework adapter will render.
 type Response struct {
 	StatusCode int
 	Headers    map[string]string
 	Body       []byte
 }
 
-// Return the content-type header from this response, or "applicatin/octet-stream"
+// ContentType returns the content-type header from this response, or "applicatin/octet-stream"
 // as per HTTP standard.
 func (r *Response) ContentType() string {
 	for k, v := range r.Headers {
@@ -48,7 +47,7 @@ type ClaimsContextKeyName string
 const DefaultClaimsContextKeyName ClaimsContextKeyName = "claims"
 
 // ErrorHandler is called by the middleware if not nil
-type ErrorHandler func(ctx context.Context, request *OidcError) *Response
+type ErrorHandler func(ctx context.Context, oidcErr *OidcError) *Response
 
 // ErrorDescription is used to pass the description of the error to ErrorHandler
 type ErrorDescription string