Problem: Currently comment detection, addition, and removal are done
by matching 'commentstring' exactly. This has the downside when users
want to add comment markers with space (like with `-- %s`
commentstring) but also be able to uncomment lines that do not contain
space (like `--aaa`).
Solution: Use the following approach:
- Line is commented if it matches 'commentstring' with trimmed parts.
- Adding comment is 100% relying on 'commentstring' parts (as is now).
- Removing comment is first trying exact 'commentstring' parts with
fallback on trying its trimmed parts.
Specifically, functions that are run in the context of the test runner
are put in module `test/testutil.lua` while the functions that are run
in the context of the test session are put in
`test/functional/testnvim.lua`.
Closes https://github.com/neovim/neovim/issues/27004.
Design
- Enable commenting support only through `gc` mappings for simplicity.
No ability to configure, no Lua module, no user commands. Yet.
- Overall implementation is a simplified version of 'mini.comment'
module of 'echasnovski/mini.nvim' adapted to be a better suit for
core. It basically means reducing code paths which use only specific
fixed set of plugin config.
All used options are default except `pad_comment_parts = false`. This
means that 'commentstring' option is used as is without forcing single
space inner padding.
As 'tpope/vim-commentary' was considered for inclusion earlier, here is
a quick summary of how this commit differs from it:
- **User-facing features**. Both implement similar user-facing mappings.
This commit does not include `gcu` which is essentially a `gcgc`.
There are no commands, events, or configuration in this commit.
- **Size**. Both have reasonably comparable number of lines of code,
while this commit has more comments in tricky areas.
- **Maintainability**. This commit has (purely subjectively) better
readability, tests, and Lua types.
- **Configurability**. This commit has no user configuration, while
'vim-commentary' has some (partially as a counter-measure to possibly
modifying 'commentstring' option).
- **Extra features**:
- This commit supports tree-sitter by computing `'commentstring'`
option under cursor, which can matter in presence of tree-sitter
injected languages.
- This commit comments blank lines while 'tpope/vim-commentary' does
not. At the same time, blank lines are not taken into account when
deciding the toggle action.
- This commit has much better speed on larger chunks of lines (like
above 1000). This is thanks to using `nvim_buf_set_lines()` to set
all new lines at once, and not with `vim.fn.setline()`.
