I have an existing react web-app, with https://github.com/gin-gonic/gin as the backend. Now I'd like to use your great package, to migrate to grpc.

To begin with, I change the existing sample project to use gin, by the following changes:

func main() {
	grpcServer := grpc.NewServer()
	hackernewsService := hackernews.NewHackerNewsService(nil)
	hackernews_pb.RegisterHackerNewsServiceServer(grpcServer, hackernewsService)

	wrappedGrpc := grpcweb.WrapServer(grpcServer)

+	r := gin.Default()
+	r.Use(LogRequest())
+	r.Use(middleware.NewGrpcWebMiddleware(wrappedGrpc).Handler2())
+	r.Use(cors.New(cors.Config{
+		AllowOrigins:     []string{"http://localhost:3000"},
+		AllowMethods:     []string{"GET", "POST", "PUT", "DELETE", "OPTIONS"},
+		AllowHeaders:     []string{"Accept", "Authorization", "Content-Type", "X-CSRF-Token", "X-GRPC-WEB"},
+		ExposeHeaders:    []string{"Link"},
+		AllowCredentials: true,
+		MaxAge:           time.Duration(300) * time.Second,
+	}))
+	r.GET("/article-proxy", proxy.Article)

+	err := r.Run(":8900")
+	if err != nil {
+		grpclog.Fatalf("failed starting http2 server: %v", err)
+	}
-	router := chi.NewRouter()
-	router.Use(
-		chiMiddleware.Logger,
-		chiMiddleware.Recoverer,
-		middleware.NewGrpcWebMiddleware(wrappedGrpc).Handler, // Must come before general CORS handling
-		cors.New(cors.Options{
-			AllowedOrigins:   []string{"*"},
-			AllowedMethods:   []string{"GET", "POST", "PUT", "DELETE", "OPTIONS"},
-			AllowedHeaders:   []string{"Accept", "Authorization", "Content-Type", "X-CSRF-Token"},
-			ExposedHeaders:   []string{"Link"},
-			AllowCredentials: true,
-			MaxAge:           300, // Maximum value not ignored by any of major browsers
-		}).Handler,
-	)

-	router.Get("/article-proxy", proxy.Article)

-	if err := http.ListenAndServe(":8900", router); err != nil {
-		grpclog.Fatalf("failed starting http2 server: %v", err)
-	}
}

and adding Handler2 method to server/middleware/grpcWeb.go

func (m *GrpcWebMiddleware) Handler2() gin.HandlerFunc {

	return func(c *gin.Context) {
		if m.IsAcceptableGrpcCorsRequest(c.Request) || m.IsGrpcWebRequest(c.Request) {
			m.ServeHTTP(c.Writer, c.Request)
			return
		}

		c.Next()
	}
}

and updating Article method to server/proxy/article.go

-func Article(w http.ResponseWriter, r *http.Request) {
+func Article(c *gin.Context) {
+	r := c.Request
+	w := c.Writer
	queryValues := r.URL.Query()
	url := queryValues.Get("q")
	if url == "" {
		http.Error(w, "Must specify the url to request", 400)
	}
	response, err := http.Get(url)
	if err != nil {
		http.Error(w, "Failed to retrieve article", 500)
	}
	if response.StatusCode >= 400 {
		if err != nil {
			http.Error(w, response.Status, response.StatusCode)
		}
	}
	reader := bufio.NewReader(response.Body)
	reader.WriteTo(w)
}

Everything is compiling and running fine, but I get the following error in the browser, when loading the page: POST http://localhost:8900/grpc_web_hacker_news.HackerNewsService/ListStories 404 (Not Found)

Chrome debugger Netwrok trace:

General:
  Request URL: http://localhost:8900/grpc_web_hacker_news.HackerNewsService/ListStories
  Request Method: POST
  Status Code: 404 Not Found
  Remote Address: [::1]:8900
  Referrer Policy: no-referrer-when-downgrade

Response Headers:
  Access-Control-Allow-Credentials: true
  Access-Control-Allow-Origin: http://localhost:3000
  Content-Type: application/octet-stream
  Date: Sun, 03 Feb 2019 17:20:48 GMT
  Transfer-Encoding: chunked
  Vary: Origin

Request Headers:
  Accept: */*
  Accept-Encoding: gzip, deflate, br
  Accept-Language: en-US,en;q=0.9,fa-IR;q=0.8,fa;q=0.7
  Cache-Control: no-cache
  Connection: keep-alive
  Content-Length: 5
  content-type: application/grpc-web+proto
  Host: localhost:8900
  Origin: http://localhost:3000
  Pragma: no-cache
  Referer: http://localhost:3000/
  User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like 
  Gecko) Chrome/71.0.3578.98 Safari/537.36
  x-grpc-web: 1

Could someone help me find out what I am missing?

Getting the error below when running yarn install in app folder

node-pre-gyp ERR! Tried to download(404): https://fsevents-binaries.s3-us-west-2.amazonaws.com/v1.1.2/fse-v1.1.2-node-v67-darwin-x64.tar.gz 

Hello,
I found this project does not work in go-chi v4 because their deprecation of http.CloseNotify. Is this confirmed?
details: improbable-eng/grpc-web#337

Only the heading appears on the page. List_stories api call is failing.
I just cloned and executed the start.sh file. @easyCZ

I can't find your webpack configuration file. Your app/README mentions the path webpack.config.prod.js which appears to be missing.

Hi,

Sorry for an unrelated question
I am currently working on using grpc-web to write a simple client for my service. I have created a service.proto file which was successfully compiled using protoc. The problem arose when I tried to generate the gRPC-Web service client stub using the plugin protoc-gen-grpc-web which doesnt work despite having installed the latter.

Got the following error :
protoc -I=./ service.proto --grpc-web_out=import_style=commonjs,mode=grpcwebtext:./
protoc-gen-grpc-web: program not found or is not executable
--grpc-web_out: protoc-gen-grpc-web: Plugin failed with status code 1.

OS : Ubuntu 18.04

Any suggestions on how to solve this issue? Thank you!

I didn't able to find the typescript version in package json. I tried using 2.8, 3.1.1, 4.4.4 versions but still getting type errors.
Also it would be helpful if you mention node version also.

I'm seeing this error when I tried to run the server:

command-line-arguments

./main.go:20:47: cannot use grpcServer (type *"google.golang.org/grpc".Server) as type *"github.com/easyCZ/grpc-web-hacker-news/server/vendor/google.golang.org/grpc".Server in argument to grpc_web_hacker_news.RegisterHackerNewsServiceServer
./main.go:28:34: cannot use wrappedGrpc (type *"github.com/improbable-eng/grpc-web/go/grpcweb".WrappedGrpcServer) as type *"github.com/easyCZ/grpc-web-hacker-news/server/vendor/github.com/improbable-eng/grpc-web/go/grpcweb".WrappedGrpcServer in argument to "github.com/easyCZ/grpc-web-hacker-news/server/middleware".NewGrpcWebMiddleware