Currently, running the test suite relies on a large number of concrete path --ignore lines, which appears to fail during discovery, even if pyproject.toml is brought along... likely due to some path issues.

Proposed

Move all tests to a top-level tests folder, keeping basically the same structure. Include this in the .tar.gz, but exclude from .whl.

Pro:

• would reducing the size of the as-installed package for most cases by about 200k, as noted on Add in-browser demo on documentation site #13936
• would drastically simplify the pytest configuration

Con:

• the tests would no longer be part of the public API...
  • IPython.testing certainly can't move (but .testing.tests could)
  • but Hyrum's Law pretty much demands that it has been in use downstream
• tests would be "further" from the things they test

Alternatives

Update the expected test procedure to use --pyargs IPython, and figure out how to ignore the discovery blockers here.

Pro:

• no change to the API

Con:

• keeps all the tests in the .whl