Create React App http-proxy-middleware not working

Question

So I've set up my proxies on my create-react-app application using http-proxy-middleware. I'm sure I've followed the instructions to the letter, but I keep getting a 404 every time I try to click the relevant link.

I'm using create-react-app v3.2.

Here's my setupProxy.js file:

const proxy = require("http-proxy-middleware");

module.exports = function(app) {
    app.use(proxy("/api", { target: "http://localhost:3090" }));
};

Here's the action creator that makes the http request

export const signIn = formProps => async dispatch => {
    try {
        const response = await axios.post("/api/login", formProps);

        //.....etc, etc
    } catch(e) {

        //.....etc,etc
    }
}

And here's the relevant route on my express server:

app.post("/login", requireSignIn, Authentication.login);

When the development server starts up, I get the following message:

[HPM] Proxy created: /api  -> http://localhost:3090

So setupProxy.js is obviously being picked up by CRA, but there's something wrong somewhere. I've tried adding wildcards to the proxy setup (e.g. "/api/*") but no luck. I get the following 404 logged in my console on the client side:

POST http://localhost:3000/api/login 404 (Not Found)

which refers to localhost:3000, suggesting that the proxy (which should redirect to localhost:3090) is not being used.

I can't help thinking that there's something really simple that I'm missing here, but currently tearing my hair out trying to get this to work.

Any help would be much appreciated.

Thanks!

Answer 1

As of v1.0.0 of http-proxy-middleware, the setupProxy.js file requires an explicit import; so instead of the previous default import

const proxy = require("http-proxy-middleware");

You need to use:

const { createProxyMiddleware } = require('http-proxy-middleware');

module.exports = function(app) {
    app.use(createProxyMiddleware("/api", { target: "http://localhost:3090" }));
};