In 2021, the @online_only decorator was rewritten to use

@simple_decorator, but the result was a function that performed no-ops

when online. Instead of calling the test function with the provided

arguments, it just returned the first argument as-is (which was the

self argument to the unit test class). This got ignored, resulting in

nothing happening when the test was run.
This did unveil that one test (Mercurial's HTTPS tests) were no longer

passing. This was due to the repository having bot protection deployed,

which meant we were getting HTTP 200 results that weren't actually the

file contents. We've switched to Mozilla's HG server for our test, which

currently has no bot protection.

Unit tests pass.