feat(react-scripts): allow PUBLIC_URL in develoment mode

[unrevised6419]

Allow PUBLIC_URL in development mode

• Feature (react-dev-utils/getPublicUrlOrPath)
• Tests
• Docs
• Types feat(react-dev-utils): add redirectServedPathMiddleware and getPublicUrlOrPath DefinitelyTyped/DefinitelyTyped#40982

Public API

• In development mode browser is opened at desired pathname
• Redirect to desired pathname if does not start with it (react-dev-utils/redirectServedPathMiddleware)
• Assets will be served at desired pathname (feat(server): add contentBasePublicPath option webpack/webpack-dev-server#2150)
• If desired pathname is a relative path, app will be served at /

Private API

• Combined paths.publicUrl and paths.servedPath into paths.publicUrlOrPath
• Extracted all logic into react-dev-utils/getPublicUrlOrPath (no side effects)
• Moved evalSourceMapMiddleware and errorOverlayMiddleware first in the middleware chain, redirect does not affect them.
• Moved proxy middleware after redirect (this is the case what most want, proxy should respect PUBLIC_URL
• Adapted noopServiceWorkerMiddleware to serve from servedPath
• Updated webpack-dev-server@3.9.0 to webpack-dev-server@3.10.0

---

Blocked by webpack/webpack-dev-server/pull/2150
Blocked by webpack/webpack-dev-server/pull/2374
Blocked by https://github.com/webpack/webpack-dev-server new patch release

Closes #6280
Closes #6135
Closes #4158

[ArnaudBarre]

packages/react-scripts/config/webpack.config.js L. 561-563 to update

[unrevised6419]

@ArnaudBarre done!

[mrmckeb]

@iansu or @ianschmitz - can I get your thoughts on this one?

[jtblanche]

this fixes the issue I mentioned at #6280 (comment) 👍

[64BitAsura]

@iansu @Timer @gaearon @amyrlam @ianschmitz @petetnt @bugzpodder please review this PR, if all good merge it ASAP and make release please 🙏 , my projects requires and also I don't want to eject since we don't have enough resource to setup packer env 😢

[mrmckeb]

@sambathl I'm chasing a second review on this, and then we can merge it in.

[heyimalex]

I don't think it works when "homepage": ".".

[heyimalex]

I think all that needs to change is webpackDevServer.config.js needs to check for the relative path when setting publicPath.

publicPath: paths.servedPath === "./" ? "/" : paths.servedPath.slice(0, -1)

[unrevised6419]

There is also a problem when setting homepage /something and opening /,
manifest.json and favicon.ico return 404 trying to load http://localhost:3000/%PUBLIC_URL%/manifest.json and http://localhost:3000/%PUBLIC_URL%/favicon.ico

Edit: In this case dev server just served clear index.html content without injecting dynamic vars

[heyimalex]

@iamandrewluca Hm, I'm actually not getting that anymore with my changes, so maybe the PUBLIC_URL thing was fixed by ad7e29b? But the dev server is definitely serving index.html when requests for favicon.ico are made if homepage is set.

[raix]

@iamandrewluca not sure if merging in master will fix the build issue / or at least rerun the build?

[unrevised6419]

@raix made a rebase to trigger the build. It seems there is a babel plugin dependency error comming from master.

[lucasmogari]

I'm trying this branch. I'm curious about why the public url have to end with a slash?

If I set the public_url with for example: "PUBLIC_URL=/test" and browse http://localhost:3000/test, it redirects the url to: http://localhost:3000/test/test

Btw, thanks for this PR, it's very useful.

[unrevised6419]

If I set the public_url with for example: "PUBLIC_URL=/test" and browse http://localhost:3000/test, it redirects the url to: http://localhost:3000/test/test

It should not, I'll check.

[lucasmogari]

Another thing I noticed is that when reloading http://localhost:3000/test/some-path, it returns a 404 error. Reloading http://localhost:3000 works.

I don't know if it's related, but I'm running the apps behind a reverse proxy (nginx).

listen 3000;

# App with PUBLIC_URL=/test
location /test {
    proxy_pass http://localhost:3020;
    proxy_set_header Host $host;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
}

location / {
    proxy_pass http://localhost:3010;
    proxy_set_header Host $host;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
}

[unrevised6419]

@lucasmogari on http://localhost:3000 is your nginx proxy?

[raix]

@lucasmogari shouldn't it be:

location /test {
    proxy_pass http://localhost:3020/test;

[lucasmogari]

It actually works both ways. According to nginx docs:

https://docs.nginx.com/nginx/admin-guide/web-server/reverse-proxy/

If the address is specified without a URI, or it is not possible to determine the part of URI to be replaced, the full request URI is passed

The refresh problem happens in both ways too. I think there's something related to what is described in the docs, but there's no guide for nginx.

https://create-react-app.dev/docs/deployment/#serving-apps-with-client-side-routing

[lucasmogari]

@lucasmogari on http://localhost:3000 is your nginx proxy?

Yes. What I'm trying to do:

http://localhost:3000 proxies to http://localhost:3010/ (main app)
http://localhost:3000/test proxies to http://localhost:3020/test (test app)

In dev, refreshing http://localhost:3000/some-path works, but http://localhost:3000/test/some-path returns 404.

[lucasmogari]

I found that adding the option (index: paths.publicUrlOrPath) to webpackDevServer.config.js fixed the problem with refreshing:

historyApiFallback: {
      // Paths with dots should still use the history fallback.
      // See https://github.com/facebook/create-react-app/issues/387.
      disableDotRule: true,
      index: paths.publicUrlOrPath,
},

[raix]

Just a kind reminder - in 5 days / the 26th of January the original pr for this pull-request turns 1 year. Not often pull-requests live this long so I'm not sure if I should bring cake or flowers? :)

(Disclaimer: I'm not trying to push or rush things - even if we desperately want this to be merged)

[unrevised6419]

@raix 😄 will live till will be merged 🌹 🌷 💮

[andriijas]

@iamandrewluca Can you rebase locally and push?

[unrevised6419]

@lucasmogari I addressed the issues you encoutnered, can you try again with the proxy?

/test now will not redirect to /test/
/test/some-path returns 200

@andriijas done!

[unrevised6419]

PR Blocked by a webpack-dev-server patch release
webpack/webpack-dev-server/pull/2374

[andriijas]

@iamandrewluca In case we forget, ping when webpack-dev-server releases a new version! Thanks for your patience!

[unrevised6419]

Ok, I'll ping. Contacted a webpack maintaner for an ETA.

[lucasmogari]

@lucasmogari I addressed the issues you encoutnered, can you try again with the proxy?

/test now will not redirect to /test/
/test/some-path returns 200

With PUBLIC_URL=/test
/test is redirecting (returns 302) to /test/test
/test/some-path (returns 200)

With PUBLIC_URL=/test/
/test/ (returns 200)

Maybe it's some configuration here. I'm sorry, but I don't have too much time to debug right now.

Thanks again!

[unrevised6419]

@lucasmogari Try in incognito mode. Or clear all data for localhost:3000
For me when I tested also redirected to /test/.
If previous was any 301 redirect from localhost:3000/test to localhost:3000/test/, browser remembers that, and will always redirect.

If I open localhost:3000/test in incognito mode, it stays on this path.

[unrevised6419]

@andriijas all done! Need review.

[andriijas]

Thanks for your patience everyone, specially @iamandrewluca

If anyone wants to do additional testing on their projects - please do!

[kelly-tock]

Well done!

[unrevised6419]

I encountered some problems when using proxy with this feature. Investigating. Think I should reorder in a right way proxy middlewares.

Also one case
Having /test homepage, any fetch ex: /api/resource will redirect to /test/api/resource which I think is wrong.

Do we revert the PR, and create a new one with fixed problems, or we fix the problem till the next release?

[unrevised6419]

Found the issue. Will make a PR soon. Internal proxy that decides to proxy or not, does not know about public path