gorilla | Convenient approach to monkey patching

I'm working on a websocket and recently started doing some tests for race conditions using race. go run -race serve.go

Getting this result:

I'm new to React and I want to implement a form where the user is given N inputs and is asked to copy/paste some contents in it (he can also click on a + or - button to add or remove some inputs but let's keep it simple for now).

The idea is that, for each input, the user will copy/paste some data and, on each input an onChange listener is attached so that each time an input is changed, it will trigger a call to an API or backend service to validate the data. Once the data is validated, it will return whether or not the user was right (by changing the background color of the input for example). Here is a picture:

The problem is that, let say the user copies/pastes gorilla in the first input and the async call takes 10s, but then 2s after it copied/pasted gorilla in the first input, he copies/pastes spaceship in the second input (and this async call takes 4s to return let's say). What happens with my current version is that, since the 2nd call finished before the first one, isValid is updated for the second input while it is not for the first input.

This is due to the fact that I'm using useEffect and the clean function. I have also tried to use useState instead but each time I ran into a race condition...

Notes:

• If the user entered gorilla in the first input and 1s after he modifies the same input and enters giraffe. If the first async call did not finish yet, I prefer to kill it and only retrieve the validation for the latest call made for that same input (this is why I used a clean function in my useEffect)
• Even if the problem of stopping the validation of other inputs is solved, I think there will always be a race condition as in my useEffect I am modifying my useState associated to each of my input so I'm not sure how to go about it.

Here is tiny sample to replicate my current behavior:

I am just getting started learning docker a few hours ago and I trying to make my own docker image. When I tried to make a Dockerfile and a docker image, I got this error message "/bin/sh: 1: source: not found".

First of all, I manage my environment variables in .env file. Whenever I change my env file, I run this command $source .env and go build . and then go run main.go. So, I tried to set up my Dockerfile, RUN source.env but I got the error that I mentioned above.

I tried

• RUN . setting.env & . setting but didn't work
• change the file name into setting.env and then RUN . ./setting.env & . ./setting & ["/bin/bash", "-c", "source ~/.setting.env"] also didn't work...

I really appreciate your help!

Edit 1]

Sometimes I want to refuse a http client's request to upgrade connection to websocket.

(using go's Gin and gorilla/websocket framework:)

To allow upgrade:

Using gorilla/websocket I dial the binance websocket endpoint, which succeeds without error. After setting the pong handler on the connection, I write a ping control message and wait for a pong to arrive at the pong handler, which never seems to happen. I use a channel, a context with timeout and a select block to check if the pong arrived.

The code:

I'm creating a React application which talks to a backend written in Go. I have setup CSRF using the Gorilla library. The React code will first send a GET request to the csrfToken endpoint where it receives a token. This token is set in the header when sending the POST request.

I have a backend written in Go, hosted on Heroku, let's call it, https://foo.herokuapp.com. I have a frontend hosted on a different domain, let's call it, https://ui.example.com. The backend API has an endpoint /api/user/login which sends back a JSON Web Token in the form of cookie shown as below:

I have a main.go file that I use to run an app that starts a server that exposes a port where I can run endpoints from. I was trying to dockerise it and got as far as making working containers that hold the app and the db, but I still seem to have to run go run main.go after running docker-compose up -d.

I followed this example for serving a NextJs front end single-page application using Golang and the native net/http package: