Phobos interdependency and public unit tests

[thewilsonator]

From this months beerconf about reducing/documenting the interdependencies between phobos modules:

Pull out publicly documented unittests and verify that no any/all selective imports are present in the unittest and no global imports from that module.

module std.foo;

import std.bar; // a global import

struct Baz { ... }

///
@safe unittest {
    import std.quux : something;
   assert 
}

->

import std.foo;
///
@safe unittest {
    import std.quux : something;
}

and check this still compiles.

[jmdavis]

The tooling isn't set up to do anything with the Phobos v3 code right now, but don't we already have a tool that's doing this for Phobos v2?

[pbackus]

Yes, it's tests_extractor.d in the dlang/tools repository, and it's invoked for Phobos (v2) with make publictests.

[thewilsonator]

NB the context for this was for phobosV2 for people that want to contribute that we can prepare ahead of time to disentangle, make the unit tests better for documentation.

[jmdavis]

I'm not sure that it would be easy to talk Walter into it, but I wonder if we should look at adding a pragma that did this so that projects in general could mark their ddoc-ed unittest blocks with it and catch when they accidentally use a private symbol or failed to have all of the necessary imports within an example.