Extend test suite:

• Testing on a matrix of different Python and OS versions
• Not running all possible combinations as that seems overkill
• Run the latest Python version (3.11 here) on all three OS's
• Not yet including Python 3.12 - I can update ✨ Add support for Python 3.12, tests in CI and official marker #807 separately after merging this.

In total, this runs the CI two more times than before (7 instead of 5).

Fixes

To get the CI to go green for all systems, following edits/fixes were required:

Ensure we're always reading in UTF-8

tests/test_tutorial/test_parameter_types/test_file/test_tutorial004(_an) failed on Windows:

AssertionError: assert 'la cig�e�a trae al ni�o' in 'some settings\nla cigüeña trae al niño'

To fix it, I set the encoding for read_text to be utf8.

Skip completion tests for Windows and MacOS

This isn't the cleanest of solutions, but it seems to me that these completion tests were very much written to work on Linux/bash only. In the future, it'd be nice to have MacOS & Windows compatible tests for this - I can make an issue for it to follow up later?

Use OS in coverage report name

By including the OS in the coverage file, we prevent overwriting / confusion:

Windows encoding issue with coverage run

Added an env argument to subprocess.run calls that were failing for the test_commands/test_help test_script tests. I'm still not clear why we were getting UnicodeDecodeError's for these. I double checked all files in the typer codebase and couldn't find any with a wrong decoding. Something must be happening when calling coverage run. Either way, by taking inspiration from cpython#105312 and chaiNNer#2815 it seems to be fixed.

MacOS issue with Python dir caching

The Python installation is being cached with actions/cache@v3, which refers to env.pythonLocation. However on macOS, this directory appears to be empty. The "Post Run" log would mention

Cache Size: ~0MB (478 B)

and then the next run would appear to "successfully" restore from this cache, but the commands wouldn't actually be available:

Cf also a related discussion actions/setup-python#813. I decided to implement the same workaround as torchgeo/torchgeo#2024, basically disabling the caching for MacOS.

Windows issue with Python dir caching

One remaining issue is to investigate why the Windows caching isn't currently working:

This is not necessary to get this PR green, so I suggest to keep this as follow-up work.

Fix combining coverage files from different OS's

When combining the different .coverage.XXX files from the different runs in the matrix, coverage needs to remap the locations. It's easier to just use the relative_files option as suggested in the Coverage docs.