flow v0.57.x don't shows no errors if use `module.system.node.resolve_dirname=src`

[gin0606]

I need help!

flow don't show any errors, if write module.system.node.resolve_dirname=src in .flowconfig

https://github.com/gin0606/flow-v0.57.1-trouble

Please see this repository, that can see my trouble.

Thanks!

Maybe related to flow/flow-bin#91 and #5105

[apsavin]

Still an issue with 0.58.0

[kogai]

I'd encountered the same problem, and dug down into a code of the Flow, then I think that I found what the reason it caused.

First, in version 0.57 of Flow, the feature as described below added

New Features:
Flow will now only check the files in node_modules/ which are direct or transitive dependencies of the non-node_modules code.

Also, the document explains about setting module.system.node.resolve_dirname as below.

module.system.node.resolve_dirname (string)
By default, Flow will look in directories named node_modules for node modules. You can configure this behavior with this option.

In other words, adding a setting to resolve_dirname means that a directory added will not be checked as well as node_modules unless imported from the file where not in the directory set to resolve_dirname and not set to the ignore option.

As far as the document explained, I think this behavior may be the intended of the Flow team.
But it will confuse some users, including me.

My workaround is to import files where Flow check lazily, from files where Flow check immediately

For example, in case of @gin0606 https://github.com/gin0606/flow-v0.57.1-trouble, we will be able to force type checking by placing the file like below in the root directory of the repository.

// ./src/index.js
// @flow
import bar from 'foo/bar';

let num: number = 1;
let numerror: number = 'string';
let string: string = bar();

console.log(num);
console.log(numerror);
console.log(string);
+ 
+ export default () => {};

// In root of repository ./root.js
+ import fn from "./src"

But the workaround seems not absolutely ideally.
My personal opinion is that it should be checked lazily node_modules directory only.
Because some users use resolve_dirname option conjunction with resolve.modules option of the Webpack.

If we need PR to make such corrections, I will be honored to make it.

However, for us to find an ideal solution about this, I would like to hear the opinion of the Flow team on this Issue especially @gabelevi 's one (because he added such feature in 385da8e).

[bradennapier]

I actually implemented a workaround for this problem. It doesn't keep the exact same behavior but you get your errors back in the case described by the OP:

Simply change:

module.system.node.resolve_dirname=src

to

module.system.node.resolve_dirname=./src

It will not give you the bubble effect but it will let you use your base directory for all imports

[apsavin]

Thanks @kogai !

For our project we've just replaced module.system.node.resolve_dirname=src with several module.name_mapper, like this:

module.name_mapper='^desktop/\(.*\)$' -> '<PROJECT_ROOT>/src/desktop/\1'

And it seems that it fixed the issue.

[bradennapier]

On the project I am using now the relative url definitely fixes the issue.

[ajhyndman]

I'd like to echo the question from @kogai.

We are using Flow in a fairly large project, with the module.system.node.resolve_dirname rule pointing to our local source code.

Maintaining a list of individual name_mapper rules is going to be quite unwieldy and error prone. Converting every import statement to a relative import will also be difficult at this stage, and seems likely to increase the fragility of our codebase.

It would be great to hear the flow team's thoughts on this issue, and investigate possible alternatives.

[qamil]

Experiencing the same issue. But here is the weird thing: on OSX it works perfectly fine. On our CI (Travis, Ubuntu 14.04.5 LTS) it fails to output any errors.
Unfortunately the workaround of a list of name_mapper rules doesn't work. Maybe a difference with others is that we run flow check with the --all flag.

[stasgavrylov]

@qamil I had the same issue just yesterday, and although I know that it probably won't help everyone, I made CI checking work by changing module.system.node.resolve_dirname=src to module.system.node.resolve_dirname=./src