feat: write error on template execution error

gateway/assets/test/main.go

@@ -157,7 +157,10 @@ func runTemplate(w http.ResponseWriter, filename string, data interface{}) {
 		http.Error(w, fmt.Sprintf("failed to parse template file: %s", err), http.StatusInternalServerError)
 		return
 	}
-	_ = tpl.Execute(w, data)
+	err = tpl.Execute(w, data)
+	if err != nil {
+		_, _ = w.Write([]byte(fmt.Sprintf("error during body generation: %v", err)))
+	}
 }
 
 func main() {

gateway/errors.go

@@ -165,14 +165,17 @@ func webError(w http.ResponseWriter, r *http.Request, c *Config, err error, defa
 	if acceptsHTML {
 		w.Header().Set("Content-Type", "text/html")
 		w.WriteHeader(code)
-		_ = assets.ErrorTemplate.Execute(w, assets.ErrorTemplateData{
+		err = assets.ErrorTemplate.Execute(w, assets.ErrorTemplateData{
 			GlobalData: assets.GlobalData{
 				Menu: c.Menu,
 			},
 			StatusCode: code,
 			StatusText: http.StatusText(code),
 			Error:      err.Error(),
 		})
+		if err != nil {
+			_, _ = w.Write([]byte(fmt.Sprintf("error during body generation: %v", err)))
+		}
 	} else {
 		http.Error(w, err.Error(), code)
 	}

gateway/handler.go

@@ -912,11 +912,14 @@ func (i *handler) handleSuperfluousNamespace(w http.ResponseWriter, r *http.Requ
 	// - redirects to intendedURL after a short delay
 
 	w.WriteHeader(http.StatusBadRequest)
-	_ = redirectTemplate.Execute(w, redirectTemplateData{
+	err = redirectTemplate.Execute(w, redirectTemplateData{
 		RedirectURL:   intendedURL,
 		SuggestedPath: intendedPath.String(),
 		ErrorMsg:      fmt.Sprintf("invalid path: %q should be %q", r.URL.Path, intendedPath.String()),
 	})
+	if err != nil {
+		_, _ = w.Write([]byte(fmt.Sprintf("error during body generation: %v", err)))
+	}
 
 	return true
 }

gateway/handler_codec.go

@@ -203,6 +203,9 @@ func (i *handler) serveCodecHTML(ctx context.Context, w http.ResponseWriter, r *
 		CodecHex:   fmt.Sprintf("0x%x", uint64(cidCodec)),
 		Node:       parseNode(blockCid, blockData),
 	})
+	if err != nil {
+		_, _ = w.Write([]byte(fmt.Sprintf("error during body generation: %v", err)))
+	}
 
 	return err == nil
 }

gateway/handler_unixfs_dir.go

@@ -212,6 +212,7 @@ func (i *handler) serveDirectory(ctx context.Context, w http.ResponseWriter, r *
 	rq.logger.Debugw("request processed", "tplDataDNSLink", globalData.DNSLink, "tplDataSize", size, "tplDataBackLink", backLink, "tplDataHash", hash)
 
 	if err := assets.DirectoryTemplate.Execute(w, tplData); err != nil {
+		_, _ = w.Write([]byte(fmt.Sprintf("error during body generation: %v", err)))
 		return false
 	}