Daemon should respect the rule that stubs are normal even with follow-imports=skip

[ilevkivskyi]

Currently this test fails, presumably because the daemon applies --follow-imports=skip to stub files as well (while it shouldn't):

[case testFineFollowImportSkipInvalidatedOnAddedStub]
# flags: --follow-imports=skip --ignore-missing-imports
# cmd: mypy main.py
[file main.py]
import other
x: str = other.x
[file other.pyi.2]
x = 1
[stale main, other]
[rechecked main, other]
[out]
==
main:2: error: Incompatible types in assignment (expression has type "int", variable has type "str")

This was found in #5556

@msullivan do you have any ideas why this may happen?

[ilevkivskyi]

It looks like same happens with --bazel incremental build.

@gvanrossum could you give some hints about why this might happen?

[gvanrossum]

(The thing we saw internally with Bazel has a completely different cause, unrelated to this issue.)

[ilevkivskyi]

Yes, I just tried to look a bit more at this, and it looks like the root cause is simple actually: daemon never supposed to work with follow_imports=normal, but apparently it should always do this for stubs.

@JukkaL what do you think about this?

Also it looks like I had some misunderstanding about how fine-grained tests work, it seems to me now that by default at every test step all the modules currently present are passed to Server.check(). This means I have previously added many tests like [case testFineAddedMissingStubs] that don't test what I wanted.

[JukkaL]

@ilevkivskyi Hmm this is pretty unfortunate. On the other hand, this has been around for a long time before this got reported, so it doesn't seem that an urgent fix is needed. We can look at this in a few weeks when the core team will have a bug fixing spree.

[msullivan]

I've looked into this some and it is no easier to properly support follow_imports=normal for stubs alone than it is to support it in general. That makes this a sub-issue of the newly opened #5870.

[msullivan]

This might be easier to fix now with the new follow-imports=normal stuff?

[JukkaL]

This might be easier now, though I can't say how easy exactly without spending some time on this.

[JukkaL]

This works now.