Problem: Using `buf=0`/`win=0` context in `vim._with` should be
equivalent to using explicit buffer/window identifier respectively.
Solution: Explicitly adjust context in case of `buf=0` or `win=0`.
Replace the busted-based Lua test runner with a repo-local harness.
The new harness runs spec files directly under `nvim -ll`, ships its own
reporter and lightweight `luassert` shim, and keeps the helper/preload
flow used by the functional and unit test suites.
Keep the file boundary model shallow and busted-like by restoring `_G`,
`package.loaded`, `package.preload`, `arg`, and the process environment
between files, without carrying extra reset APIs or custom assertion
machinery.
Update the build and test entrypoints to use the new runner, add
black-box coverage for the harness itself, and drop the bundled
busted/luacheck dependency path.
AI-assisted: Codex
refactor(lua): add integer coercion helpers
Add vim._tointeger() and vim._ensure_integer(), including optional base
support, and switch integer-only tonumber()/assert call sites in the Lua
runtime to use them.
This also cleans up related integer parsing in LSP, health, loader, URI,
tohtml, and Treesitter code.
supported by AI
