Test filter! deprecation function

[kshyatt]

I'm not trying to test the deprecated method itself so much as this wrapper we have around it, which is chilling in base. If we don't want to test deprecation pass throughs at all feel free to close!

[martinholters]

As the warning is produced using depwarn, it errors on CI due to --depwarn=error. Not sure whether that is the right thing to do for this particular warning, though...

[fredrikekre]

That function will be removed when then deprecations are removed, see #23311 and the note here:

julia/base/deprecated.jl

Lines 1628 to 1629 in caa7f04

	# issue #17886
	# deprecations for filter[!] with 2-arg functions are in associative.jl

. We typically don't test deprecated stuff, right?

[martinholters]

We typically don't test deprecated stuff, right?

True. And sure enough there have been a bunch of errors in deprecations in the past. So a framework for testing deprecations would be ice to have. I imagine something like @test_deprecated deprecated_function() == expected_result which behaves like @test, @test_warn, or @test_throws depending on the setting of --depwarn. All @test_deprecateds could then be collected in a file that is run three times, once for each possible setting of --depwarn. (Do we have an issue for that, yet?)

[fredrikekre]

Do we have an issue for that, yet?

#20348

[KristofferC]

Seems obsolete now with deprecations removed.