fix: propagate error in HTTP compat handlers

uptrace · Nov 9, 2021 · 5ed4d41 · 5ed4d41
1 parent 4dcdf2e
commit 5ed4d41
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Showing 2 changed files with 38 additions and 3 deletions.
diff --git a/example/cors/main.go b/example/cors/main.go
@@ -1,6 +1,7 @@
 package main
 
 import (
+	"errors"
 	"fmt"
 	"html/template"
 	"log"
@@ -19,17 +20,21 @@ func main() {
 	router.GET("/", indexHandler)
 
 	router.NewGroup("/api/v1",
+		bunrouter.WithMiddleware(errorMiddleware),
 		// Install CORS only for this group.
 		bunrouter.WithMiddleware(corsMiddleware),
 		bunrouter.WithGroup(func(g *bunrouter.Group) {
 			g.GET("/users/:id", userHandler)
+			g.GET("/error", failingHandler)
 		}))
 
 	router.NewGroup("/api/v2",
+		bunrouter.WithMiddleware(errorMiddleware),
 		// Install CORS only for this group.
 		bunrouter.WithMiddleware(newCorsMiddleware([]string{"http://localhost:9999"})),
 		bunrouter.WithGroup(func(g *bunrouter.Group) {
 			g.GET("/users/:id", userHandler)
+			g.GET("/error", failingHandler)
 		}))
 
 	log.Println("listening on http://localhost:9999")
@@ -73,6 +78,16 @@ func newCorsMiddleware(allowedOrigins []string) bunrouter.MiddlewareFunc {
 	}
 }
 
+func errorMiddleware(next bunrouter.HandlerFunc) bunrouter.HandlerFunc {
+	return func(w http.ResponseWriter, req bunrouter.Request) error {
+		err := next(w, req)
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+		}
+		return err
+	}
+}
+
 //------------------------------------------------------------------------------
 
 func indexHandler(w http.ResponseWriter, req bunrouter.Request) error {
@@ -91,11 +106,19 @@ func userHandler(w http.ResponseWriter, req bunrouter.Request) error {
 	})
 }
 
+func failingHandler(w http.ResponseWriter, req bunrouter.Request) error {
+	return errors.New("just an error")
+}
+
 var indexTmpl = `
 <html>
   <h1>Welcome</h1>
   <ul>
     <li><a href="/api/v1/users/123">/api/v1/users/123</a></li>
+    <li><a href="/api/v1/error">/api/v1/error</a></li>
+
+    <li><a href="/api/v2/users/123">/api/v2/users/123</a></li>
+    <li><a href="/api/v2/error">/api/v2/error</a></li>
   </ul>
 </html>
 `

diff --git a/request.go b/request.go
@@ -28,10 +28,22 @@ func HTTPHandler(handler http.Handler) HandlerFunc {
 
 // HTTPHandlerFunc converts http.HandlerFunc to bunrouter.HandlerFunc.
 func HTTPHandlerFunc(handler http.HandlerFunc) HandlerFunc {
-	return func(w http.ResponseWriter, req Request) error {
+	return func(w http.ResponseWriter, req Request) (err error) {
 		ctx := contextWithParams(req.Context(), req.params)
+
+		defer func() {
+			if v := recover(); v != nil {
+				var ok bool
+				err, ok = v.(error)
+				if !ok {
+					panic(v)
+				}
+			}
+		}()
+
 		handler.ServeHTTP(w, req.Request.WithContext(ctx))
-		return nil
+
+		return err
 	}
 }
 
@@ -41,7 +53,7 @@ var _ http.Handler = (*HandlerFunc)(nil)
 
 func (h HandlerFunc) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 	if err := h(w, NewRequest(req)); err != nil {
-		http.Error(w, err.Error(), http.StatusInternalServerError)
+		panic(err)
 	}
 }