kommentary

Neovim plugin to comment text in and out, written in lua. Supports commenting out the current line, a visual selection and a motion.

Getting started

Install

You can install the plugin using your favorite plugin manager, just make sure you remove any plugins that might conflict with this one, such as vim-commentary.

Packer

use 'b3nj5m1n/kommentary'

Vim-Plug

Plug 'b3nj5m1n/kommentary'

Default Keybindings

The default keybindings are the same as in vim-commentary. That means you an toggle comments for the current line using gcc, for the current visual selection using gc, and in combination with a motion using gc, for example gc5j.

There's also some more advanced mappings which you can activate if you put this in your init.lua:

require('kommentary.config').use_extended_mappings()

The new mappings are:

• leader cic will increase commenting level for the current line, ci will do the same for a visual selection or motion
• leader cdc will decrease commenting level for the current line, di will do the same for a visual selection or motion

Which behind the scenes calls the following chunk of code, which you could also execute yourself with keybindings of your choice:

vim.api.nvim_set_keymap("n", "<leader>cic", "<Plug>kommentary_line_increase", {})
vim.api.nvim_set_keymap("n", "<leader>ci", "<Plug>kommentary_motion_increase", {})
vim.api.nvim_set_keymap("v", "<leader>ci", "<Plug>kommentary_visual_increase", {})
vim.api.nvim_set_keymap("n", "<leader>cdc", "<Plug>kommentary_line_decrease", {})
vim.api.nvim_set_keymap("n", "<leader>cd", "<Plug>kommentary_motion_decrease", {})
vim.api.nvim_set_keymap("v", "<leader>cd", "<Plug>kommentary_visual_decrease", {})

If you don't want to use the default mappings, you can disable the creation of those using the kommentary_create_default_mappings variable. Be sure to set the value before the plugin is loaded though.

vim.g.kommentary_create_default_mappings = false

You can then map those actions yourself (You might need to do that after the plugin is loaded), for example:

vim.api.nvim_set_keymap("n", "<leader>cc", "<Plug>kommentary_line_default", {})
vim.api.nvim_set_keymap("n", "<leader>c", "<Plug>kommentary_motion_default", {})
vim.api.nvim_set_keymap("v", "<leader>c", "<Plug>kommentary_visual_default", {})

Configuration

For most users, configuration should hardly be necessary, I try to provide sane defaults and the plugin, once installed, can basically be used as a drop-in replacement for vim-commentary. That being said, maybe you have some different preferences, or you like your editor heavily customised, this plugin should still have you covered.

The config module provides a convenience function called configure_language which makes it easy to configure a language.

Configure unsupported language

Most languages have basic support out of the box, thanks to commentstring. Unfortunately however, for some languages commentstring is not set. Also, commentstring supports either single-line or multi-line comments, not both. For those reasons, you might prefer to properly configure a language. You can do it like this:

lua << EOF
require('kommentary.config').configure_language("rust", {
    single_line_comment_string = "//",
    multi_line_comment_strings = {"/*", "*/"},
})
EOF

If one of those two is not supported by the language, set the value to false, otherwise the default (// for single-line and {/*,*/} for multi-line) will be used.

Always use single/multi-line comments

Some languages might technically support multi-line comments but have some quirks with them, or maybe you just prefer single-line comments. The proper way to configure this is:

lua << EOF
require('kommentary.config').configure_language("rust", {
    prefer_single_line_comments = true,
})
EOF

It also works the other way:

lua << EOF
require('kommentary.config').configure_language("rust", {
    prefer_multi_line_comments = true,
})
EOF

If you set both of them to true, it will use the default.

You can also set global defaults, these will be used for all languages, unless you overwrite it for that specific language like shown above:

lua << EOF
require('kommentary.config').configure_language("default", {
    prefer_single_line_comments = true,
})
EOF

More configuration options

The configure_language provides access to two other options, use_consistent_indentation and ignore_whitespace. Both are set to true by default, but of course you can overwrite that.

use_consistent_indentation

use_consistent_indentation will cause blocks commented in with prefer_single_line_comments enabled to all have the comment prefix in the same column:

-- local function example()
--    print("Example")
-- end

Instead of

-- local function example()
    -- print("Example")
-- end

ignore_whitespace

ignore_whitespace will cause lines that don't contain anything to be ignored, it's as simple as that.

-- function test_function_1()
--     print("test")
-- end

-- function test_function_2()
--     print("test")
-- end

Instead of

-- function test_function_1()
--     print("test")
-- end
--
-- function test_function_2()
--     print("test")
-- end

Advanced configuration

This plugin allows for very individual configuration, pretty much every operation the plugin does is broken up into smaller functions, all of which are exposed and can be called in a custom function, which you can easily assign to a mapping of your choice, meaning you can incorporate some of the functionality of this plugin into your own lua functions. For more information, you can either read the source code (I do my best to leave helpful comments) or build the documentation.

Here is a simple example in which this plugin only plays a minor role, so it should be easy to understand (If you're a little familiar with neovim's lua api). We'll create mapping that, when called, inserts a new comment under the current line and puts us in insert mode.

local config = require('kommentary.config')

--[[ This function will be called automatically by the mapping, the first
argument will be the line that is being operated on. ]]
function insert_comment_below(...)
    local args = {...}
    -- This includes the commentstring
    local configuration = config.get_config(0)
    local line_number = args[1]
    -- Get the current content of the line
    local content = vim.api.nvim_buf_get_lines(0, line_number-1, line_number, false)[1]
    --[[ Get the level of indentation of that line (Find the index of the
    first non-whitespace character) ]]
    local indentation = string.find(content, "%S")
    --[[ Create a string with that indentation, with a dot at the end so that
    kommentary respects that indentation ]]
    local new_line = string.rep(" ", indentation-1) .. "."
    -- Insert the new line underneath the current one
    vim.api.nvim_buf_set_lines(0, line_number, line_number, false, {new_line})
    -- Comment in the new line
    require('kommentary.kommentary').comment_in_line(line_number+1, configuration)
    -- Set the cursor to the correct position
    vim.api.nvim_win_set_cursor(0, {vim.api.nvim_win_get_cursor(0)[1]+1, #new_line+2})
    -- Change the char under cursor (.)
    vim.api.nvim_feedkeys("cl", "n", false)
end

--[[ This is a method provided by kommentary's config, it will take care of
setting up a <Plug> mapping. The last argument is the optional callback
function, meaning when we execute this mapping, this function will be
called instead of the default. --]]
config.add_keymap("n", "kommentary_insert_below", config.context.line, {}, "insert_comment_below")
-- Set up a regular keymapping to the new <Plug> mapping
vim.api.nvim_set_keymap('n', '<leader>co', '<Plug>kommentary_insert_below', { silent = true })

Contributing

Any and all contributions are greatly appreciated!

Issues

If you found a bug or want to request a feature, pleases do so by raising an issue.

Pull Requests

1. Fork the Project
2. Create your Feature Branch (git checkout -b amazing_feature)
3. Make your changes
4. Commit your Changes (git commit -m 'Add some amazing feature')
5. Push to the Branch (git push origin amazing_feature)
6. Open a Pull Request

Please try your best to follow the style of the rest of the codebase, even though there's no official spec or linter for it. (Try not to exceed 80 lines, use snake_case)

Documentation

The code is heavily commented, functions are documented using LDoc.

You can build the documentation with this command:

ldoc .

Then you can access it from doc/index.html

Tests

There are unit tests available in the directory lua/test, you'll need to have luaunit installed, then run:

cd ./lua/
lua test/test_util.lua

# You might need to specify the lua version because luaunit doesn't support the latest ones
# lua5.3 test/test_util.lua

# For verbose output (Which tests are being run)
# lua test/test_util.lua -v

Or to run all tests:

cd ./lua/
./run_tests.sh

Atm, these unit tests don't cover a lot of the plugin because with luaunit we don't have access to the neovim api, meaning these aren't really that useful. They're also often outdated.