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:
nvim_create_autocmd() isn't |api-fast|, so modules that create autocmds
(e.g. vim.treesitter.query) can't be require()d in a fast event context.
Solution:
Mark it |api-fast|. Compile autocmd patterns with RE_NOBREAK so
aucmd_next() won't os_breakcheck() mid-iteration, where a fast
nvim_create_autocmd() could realloc the autocmds vector and dangle the
caller's AutoPat/AutoCmd.
RE_NOBREAK is low-risk because:
- aucmd_next()'s loop checks CTRL-C: `(for (… i < apc->ausize && !got_int; …)`.
- `line_breakcheck()` (`autocmd.c:1912`) runs once per matched autocmd.
- Each autocmd _execution_ runs through `do_cmdline`, which has its own
breakchecks.
However this does admit risk of a pathological case:
a catastrophic-backtracking glob matched against a very long `User`
event-pattern.
Co-authored-by: Riley Bruins <ribru17@hotmail.com>
Co-authored-by: zeertzjq <zeertzjq@outlook.com>
