Problem:
The magic globals `it`, `describe`, etc., are more trouble than they are
worth.
- Hooking into `after_each` requires `getfenv()` hacks.
- They confuse luals/emmylua, because the top-level `.luarc.json` isn't
merged with `test/.luarc.json` (apparently a luals limitation?)
- They totally defeat discoverability because the user just has to
"know" about the various magic symbols.
So they harm DX, which means they serve no purpose at all.
Solution:
- Expose the test API from `testutil`, so tests can call `t.it()`,
`t.describe()`, etc., in the conventional way.
- Drop `getfenv()` hacks.
- Drop the `setfenv()` injection in `load_chunk`.
- Drop `test/_meta.lua`.
Problem:
- Since c57f6b28d7#8519, sockets are created in ~/.local/… but XDG
spec says: "XDG_RUNTIME_DIR: Must be on the local filesystem", which
implies that XDG_STATE_DIR is potentially non-local.
- Not easy to inspect Nvim-created temp files (for debugging etc).
Solution:
- Store sockets in stdpath('run') ($XDG_RUNTIME_DIR).
- Establish "/tmp/nvim.user/" as the tempdir root shared by all Nvims.
- Make ok() actually useful.
- Introduce assert_nolog().
closes#3517closes#17093
Used
sed -r -i -e '/ helpers =/ s/$/\nlocal itp = helpers.gen_itp(it)/; s/^(\s*)it\(/\1itp(/' test/unit/**/*_spec.lua
to alter all tests. Locally they all run fine now.
Reasoning:
1. General: state from one test should not affect other tests.
2. Local: travis build is failing with something which may be an output of
garbage collector. This should prevent state of the garbage collector from
interferring as well.
