Flow: What is "@flow strict"?

[lll000111]

Found in the 0.65 release notes.

https://github.com/facebook/flow/commit/7e4834868b34d7c3e76c378076700c61a06b8994

It mentions "@flow strict" several times. I never heard of a strict modifier for the @flow tag, nor can I find anything about it.

EDIT

Found https://github.com/facebook/flow/blob/master/Changelog.md#0580

Support for user-defined "strict" mode. Using @flow strict instead of @flow in the header will now additionally fire lint rules that can be listed in the [strict] section of .flowconfig.

I'll leave this open because it should be documented somewhere else than some old release notes.

[sharno]

Just for completion, this is related to the [strict] section in config which isn't documented yet as well https://flow.org/en/docs/config/

[gkz]

I will add docs for this soon!

[pascallaprade-beslogic]

Until the documentation is done, is there anything particular I should do in order to configure the strict mode?

Reading the excerpt from the changelog in the original post, it is my understanding that I should be able to use the [strict] section in the same way as the [lints]'s, but when I try, I end up with the following error:

.flowconfig:29 Invalid strict mode lint "all=error" encountered.

I tried using different rules than all, but the error remained...

[TrySound]

@pascallaprade-beslogic
it's just a list of lint rules without values. And all doesn't work. All rules became error in strict mode.

[strict]
sketchy-null
untyped-type-import

[gkz]

I would recommend:

[strict]
nonstrict-import
unclear-type
unsafe-getters-setters
untyped-import
untyped-type-import
sketchy-null

[pascallaprade-beslogic]

Aaaah, I see! Thank you very much!

[gkz]

Here are the docs guys!

https://flow.org/en/docs/strict/

[pascallaprade-beslogic]

Awesome! Thank you!

[texastoland]

@gkz works on Flow how cool! Could your recommended config not be default?

😄 prelude.ls was how I discovered FP.