Flow: focus-check should accepts more than one file

[avaly]

flow focus-check allows to check a single file, which can be useful in some cases.

In other cases, it would be helpful to get focus-check to check all files received as arguments. For example, to use together with https://github.com/okonet/lint-staged and have only the staged files being checked.

This should be possible:

flow focus-check a.js b.js

Actual result:

flow: unexpected argument 'b.js'.

[yantakus]

Any updates on this? Would be great to have.

[jabacchetta]

Also interested in this. Jest has the flag --findRelatedTests which handles this perfectly. One potential lint-staged setup (with the proposed feature) would look something along the lines of:

"lint-staged": {
    "*.js": [
      "eslint --fix --ignore-pattern '**/*.test.js'",
      "jest --bail --findRelatedTests",
      "flow related-check",
      "git add"
    ]
  }

Lint, run tests, and type-check before commits.

[KacperKozak]

Improved performance of flow focus-check for multiple files
https://github.com/facebook/flow/releases/tag/v0.56.0

I checked it out, it works.

[yantakus]

Can someone clarify how focus-check works? Didn't find any documentation on this command.

As I understand it checks all the dependencies of provided files and dependencies of dependencies. And as the result in my case when I provide any 2 files, it returns 850 errors (I have 859 errors in total).

Is there a way to still check all dependencies (I understand this is required) but display only errors found in provided files?

We want to fix all flow errors gradually with pre-commit hook, not all of them at once.

[sibelius]

can we filter the result of focus-check to only the selected files?

[julioxavierr]

Can we have an update about the question above?

[joelruns]

For further motivation of adding feature asked about in @sibelius post above, flow focus-check is needed for usage with arc lint or tools like pre-commit. If multiple files share a dependency, the output will be littered with duplicate errors, making things more difficult to parse.