Flow: Flow does not find files behind a symbolic link directory path

[lll000111]

Flow: 0.46
Platform: Windows 10 (git-bash)

TL;DR: Files in a symlinked directory are not found, Flow does not seem to follow symlinks at least on Windows.

Tiny test project: Test.zip

WARNING: The ZIP included the sym-linked directory as full directory! Remove Test/src/system/ and create a symlink with (on Windows) mklink /D system nodejs inside Test/src/. If you just unzip it and run Flow there are no errors - obviously.

I use a symbolic link to link to one of my three directories with platform-dependent code (nodejs, browser, react-native). They all have the exact same files and API, just the platform-dependent part of the implementation.

Then I created a symbolic link named system pointing to the directory with the platform-dependent files. Before that I had ./nodejs/someFile.js in all require('...') commands and used a build process to replace the "nodejs" with whatever platform the build was for.

So after switching to this much cleaner method (no code rewrites) Flow gives me a Required module not found error for each one of the imports that look similar to require('./system/storage-base.js'); (before it was require('./nodejs/storage-base.js'); in the src/ directory and "nodejs" replaced after build in the lib/ directory).

WebStorm has no problem with the symlink (just an aside).

I found #149 but that was closed by the author without giving a reason.

Also: https://github.com/facebook/flow/issues/46#issuecomment-64593695

And also https://github.com/facebook/flow/issues/164 -- this sounds as if it should work when the Flow server is restarted and that only watching for changes is the issue, but I did restart flow.exe and it made no difference.

[torarnek]

Any progress on this?

This makes it hard to used linked modules with flow, e.g. yarn link.

[juancampa]

I can confirm flow fails to find a module that exists in node_module as a perfectly valid symlink created through yarn link. Node has no problem require-ing it.

[rvion]

this turns out really painful to deal with in complex codebases

[dwwoelfel]

This will also prevent flow types from working in development for dependent packages in yarn workspaces.

[mjg17]

I've just encountered this, in the context of using yarn link to work on an app and a related module.

It would be really nice if flow could follow yarn link links.

[mjg17]

It turns out that the workaround in #164 works for me (on Linux) - stop and restart the flow server after setting up the yarn link.

Ideally flow would notice without a restart, but at least there is a workaround.

[willisplummer]

Stopping and starting flow resolved this issue for me

[andiwinata]

using flow check works for me

[lll000111]

@andiwinata Why do you post a comment if you don't have this issue??? The 2nd guy who tells us that they don't have a problem. Did you test THIS specific problem? Did you check with the test project included in the initial comment (and follow the instructions to reproduce!)?

[andiwinata]

hi @lll000111 , my bad, sorry about that.

I was searching for issue about yarn link and this issue popped up, and saw the comment about restarting flow fixed the issue - which is true. Thus I commented using flow check will work too since it seems using new flow server every time it runs.

Again sorry for hijacking your issue

[lll000111]

@andiwinata

the comment about restarting flow fixed the issue - which is true

THIS issue, or your issue? As I said, did you try to reproduce this issue?

[vladp]

Does not work for me either
Windows 10/

  "flow-bin": "^0.77.0",
    "flow-typed": "^2.5.1",

The .flowconfig
module.name_mapper='^web_common' ->'/csr-cra/src/wc.src'

cannot process

import {something} from 'web_common/Someting';

The symlink on windows is
<SYMLINKD> wc.src [..\..\..\web.common\wc.src\]

under src/

(I also tried
module.name_mapper='^web_common' ->'<PROJECT_ROOT>/src/wc.src' )

[vladp]

I have gotten this work on windows.

The [include] option in the .flowconfig has to point to the physical directory associated with the given symlinked directory
Notice, now in my updated .flowconfig the directory in the the [include] option points to the actuall (relative, but not symlinked) location.

[ignore]

.*/node_modules/.*
.*/build/.*
config-overrides.js
.*/src/registerServiceWorker.js
.*/src/index.js

.*/config-overrides.js


[include]


../../web.common



[libs]
flow-typed

[lints]

[options]

all=true

module.system.node.resolve_dirname=node_modules
module.name_mapper='^react-native' ->'node_modules/react-native-web'
module.name_mapper='^web_common' ->'src/wc.src'

esproposal.decorators=ignore
esproposal.class_static_fields=enable
esproposal.class_instance_fields=enable

suppress_type=$FlowIssue
suppress_type=$FlowFixMe



[strict]

[nate-whil]

@vladp that was my issue as well https://flow.org/en/docs/config/include/