docs: Lua plugin development guide

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Justin M. Keyes
2025-09-01 18:52:35 -04:00
parent 28ab656122
commit a5e7ccc329
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@@ -2,7 +2,7 @@
NVIM REFERENCE MANUAL
Guide to developing Lua plugins for Nvim
Guide to developing Lua plugins for Nvim
Type |gO| to see the table of contents.
@@ -10,11 +10,32 @@
==============================================================================
Introduction *lua-plugin*
This is a guide for getting started with Nvim plugin development. It is not
intended as a set of rules, but as a collection of recommendations for good
practices.
This document provides guidance for developing Nvim (Lua) plugins:
For a guide to using Lua in Nvim, please refer to |lua-guide|.
See |lua-guide| for guidance on using Lua to configure and operate Nvim.
See |luaref| and |lua-concepts| for details on the Lua programming language.
==============================================================================
Creating your first plugin *lua-plugin-new*
Any Vimscript or Lua code file that lives in the right directory,
automatically is a "plugin". There's no maniest or "registration" required.
You can try it right now:
1. Visit your config directory: >
:exe 'edit' stdpath('config')
<
2. Create a `plugin/foo.lua` file in there.
3. Add something to it, like: >lua
vim.print('Hello World')
<
4. Start `nvim` and notice that it prints "Hello World" in the messages area.
Check `:messages` if you don't see it.
Besides `plugin/foo.lua`, which is always run at startup, you can define Lua
modules in the `lua/` directory. Those modules aren't loaded until your
`plugin/foo.lua`, the user, calls `require(…)`.
==============================================================================
Type safety *lua-plugin-type-safety*
@@ -24,24 +45,24 @@ virtually immediate feedback.
But for larger projects, this can be a double-edged sword, leaving your plugin
susceptible to unexpected bugs at the wrong time.
You can leverage LuaCATS https://luals.github.io/wiki/annotations/
annotations, along with lua-language-server https://luals.github.io/ to catch
potential bugs in your CI before your plugin's users do.
You can leverage LuaCATS or "emmylua" annotations https://luals.github.io/wiki/annotations/
along with lua-language-server ("LuaLS") https://luals.github.io/ to catch
potential bugs in your CI before your plugin's users do. The Nvim codebase
uses these annotations extensively.
------------------------------------------------------------------------------
Tools *lua-plugin-type-safety-tools*
TOOLS
- lua-typecheck-action https://github.com/marketplace/actions/lua-typecheck-action
- lua-language-server https://luals.github.io
==============================================================================
Keymaps *lua-plugin-keymaps*
Keymaps *lua-plugin-keymaps*
Avoid creating keymaps automatically, unless they are not controversial. Doing
so can easily lead to conflicts with user |mapping|s.
Avoid creating excessive keymaps automatically. Doing so can conflict with
user |mapping|s.
NOTE: An example for uncontroversial keymaps are buffer-local |mapping|s for
specific file types or floating windows.
specific file types or floating windows, or <Plug> mappings.
A common approach to allow keymap configuration is to define a declarative DSL
https://en.wikipedia.org/wiki/Domain-specific_language via a `setup` function.
@@ -81,25 +102,24 @@ Some benefits of exposing a Lua function are:
NOTE: If your function takes an options table, users may still benefit
from |<Plug>| mappings for the most common combinations.
------------------------------------------------------------------------------
Example *lua-plugin-plug-mapping-example*
KEYMAP EXAMPLE
In your plugin:
>lua
vim.keymap.set("n", "<Plug>(SayHello)", function()
print("Hello from normal mode")
vim.keymap.set('n', '<Plug>(SayHello)', function()
print('Hello from normal mode')
end, { noremap = true })
vim.keymap.set("v", "<Plug>(SayHello)", function()
print("Hello from visual mode")
vim.keymap.set('v', '<Plug>(SayHello)', function()
print('Hello from visual mode')
end, { noremap = true })
<
In the user's config:
>lua
vim.keymap.set({"n", "v"}, "<leader>h", "<Plug>(SayHello)")
vim.keymap.set({'n', 'v'}, '<leader>h', '<Plug>(SayHello)')
<
==============================================================================
Initialization *lua-plugin-initialization*
Initialization *lua-plugin-init*
Newcomers to Lua plugin development will often put all initialization logic in
a single `setup` function, which takes a table of options.
@@ -109,8 +129,8 @@ your plugin, even if they are happy with the default configuration.
Strictly separated configuration and smart initialization allow your plugin to
work out of the box.
NOTE: A well designed plugin has minimal impact on startup time.
See also |lua-plugin-lazy-loading|.
NOTE: A well designed plugin has minimal impact on startup time. See also
|lua-plugin-lazy|.
Common approaches to a strictly separated configuration are:
@@ -124,37 +144,45 @@ Typically, automatic initialization logic is done in a |plugin| or |ftplugin|
script. See also |'runtimepath'|.
==============================================================================
Lazy loading *lua-plugin-lazy-loading*
Lazy loading *lua-plugin-lazy*
When it comes to initializing your plugin, assume your users may not be using
a plugin manager that takes care of lazy loading for you.
Making sure your plugin does not unnecessarily impact startup time is your
responsibility. A plugin's functionality may evolve over time, potentially
leading to breakage if users have to hack into the loading mechanisms.
Furthermore, a plugin that implements its own lazy initialization properly will
likely have less overhead than the mechanisms used by a plugin manager or user
to load that plugin lazily.
Some users like to micro-manage "lazy loading" of plugins by explicitly
configuring which commands and key mappings load the plugin.
Your plugin should not depend on every user micro-managing their configuration
in such a way. Nvim has a mechanism for every plugin to do its own implicit
lazy-loading (in Vimscript it's called |autoload|), via `autoload/`
(Vimscript) and `lua/` (Lua). Plugin authors can provide "lazy loading" by
providing a `plugin/<name>.lua` file which defines their commands and
keymappings. This file should be small, and should not eagerly `require()` the
rest of your plugin. Commands and mappings should do the `require()`.
Guidance:
- Plugins should arrange their "lazy" behavior once, instead of expecting every user to micromanage it.
- Keep `plugin/<name>.lua` small, avoid eagerly calling `require()` on modules
until a command or mapping is actually used.
------------------------------------------------------------------------------
Defer `require` calls *lua-plugin-lazy-loading-defer-require*
Defer require() calls *lua-plugin-defer-require*
|plugin| scripts should not eagerly `require` Lua modules.
`plugin/<name>.lua` scripts (|plugin|) are eagerly run at startup; this is
intentional, so that plugins can setup the (minimal) commands and keymappings
that users will use to invoke the plugin. This also means these "plugin/"
files should NOT eagerly `require` Lua modules.
For example, instead of:
>lua
local foo = require("foo")
vim.api.nvim_create_user_command("MyCommand", function()
local foo = require('foo')
vim.api.nvim_create_user_command('MyCommand', function()
foo.do_something()
end, {
-- ...
})
end, { -- ... })
<
which will eagerly load the `foo` module and any other modules it imports
eagerly, you can lazy load it by moving the `require` into the command's
implementation.
which calls `require('foo')` as soon as the module is loaded, you can
lazy-load it by moving the `require` into the command's implementation:
>lua
vim.api.nvim_create_user_command("MyCommand", function()
local foo = require("foo")
vim.api.nvim_create_user_command('MyCommand', function()
local foo = require('foo')
foo.do_something()
end, {
-- ...
@@ -165,23 +193,23 @@ defer `require` calls too.
NOTE: For a Vimscript alternative to `require`, see |autoload|.
NOTE: In case you are worried about eagerly creating user commands, autocommands
or keymaps at startup:
Plugin managers that provide abstractions for lazy-loading plugins on
such events will need to create these themselves.
NOTE: If you are worried about eagerly creating user commands, autocommands or
keymaps at startup: Plugin managers that provide abstractions for lazy-loading
plugins on such events do the same amount of work. There is no performance
benefit for users to define lazy-loading entrypoints in their configuration
instead of plugins defining it in `plugin/<name>.lua`.
NOTE: You can use |--startuptime| to |profile| the impact a plugin has on
startup time.
startup time.
------------------------------------------------------------------------------
Filetype-specific functionality *lua-plugin-lazy-loading-filetype*
Filetype-specific functionality *lua-plugin-filetype*
Consider making use of |filetype| for any functionality that is specific to a
filetype, by putting the initialization logic in a `ftplugin/{filetype}.lua`
Consider making use of 'filetype' for any functionality that is specific to
a filetype, by putting the initialization logic in a `ftplugin/{filetype}.lua`
script.
------------------------------------------------------------------------------
Example *lua-plugin-lazy-loading-filetype-example*
FILETYPE EXAMPLE
A plugin tailored to Rust development might have initialization in
`ftplugin/rust.lua`:
@@ -197,12 +225,12 @@ A plugin tailored to Rust development might have initialization in
local bufnr = vim.api.nvim_get_current_buf()
-- do something specific to this buffer,
-- e.g. add a |<Plug>| mapping or create a command
vim.keymap.set("n", "<Plug>(MyPluginBufferAction)", function()
print("Hello")
vim.keymap.set('n', '<Plug>(MyPluginBufferAction)', function()
print('Hello')
end, { noremap = true, buffer = bufnr, })
<
==============================================================================
Configuration *lua-plugin-configuration*
Configuration *lua-plugin-config*
Once you have merged the default configuration with the user's config, you
should validate configs.
@@ -215,12 +243,18 @@ Validations could include:
check, to reduce overhead.
==============================================================================
Troubleshooting *lua-plugin-troubleshooting*
Troubleshooting *lua-plugin-troubleshooting*
------------------------------------------------------------------------------
Health *lua-plugin-troubleshooting-health*
While developing a plugin, you can use the |:restart| command to see the
result of code changes in your plugin.
Provide health checks in `lua/{plugin}/health.lua`.
HEALTH
Nvim's "health" framework gives plugins a simple way to report status checks
to users. See |health-dev| for an example.
Basically, this just means your plugin will have a `lua/{plugin}/health.lua`
file. |:checkhealth| will automatically find this file when it runs.
Some things to validate:
@@ -229,19 +263,18 @@ Some things to validate:
- Presence of Lua dependencies (e.g. other plugins)
- Presence of external dependencies
See also |vim.health| and |health-dev|.
------------------------------------------------------------------------------
Minimal config template *lua-plugin-troubleshooting-minimal-config*
MINIMAL CONFIG TEMPLATE
It can be useful to provide a template for a minimal configuration, along with
a guide on how to use it to reproduce issues.
==============================================================================
Versioning and releases *lua-plugin-versioning-releases*
Versioning and releases *lua-plugin-versioning*
Consider
Consider:
- Use |vim.deprecate()| or a `---@deprecate` annotation when you need to
communicate a (future) breaking change or discourged practice.
- Using SemVer https://semver.org/ tags and releases to properly communicate
bug fixes, new features, and breaking changes.
- Automating versioning and releases in CI.
@@ -249,13 +282,11 @@ Consider
has dependencies or components that need to be built; or if it could be a
dependency for another plugin.
------------------------------------------------------------------------------
Further reading *lua-plugin-versioning-releases-further-reading*
FURTHER READING
- Luarocks <3 Nvim https://github.com/nvim-neorocks/sample-luarocks-plugin
- Luarocks ❤️ Nvim https://github.com/nvim-neorocks/sample-luarocks-plugin
------------------------------------------------------------------------------
Tools *lua-plugin-versioning-releases-tools*
VERSIONING TOOLS
- luarocks-tag-release
https://github.com/marketplace/actions/luarocks-tag-release
@@ -265,14 +296,14 @@ Tools *lua-plugin-versioning-releases-tools*
https://github.com/semantic-release/semantic-release
==============================================================================
Documentation *lua-plugin-documentation*
Documentation *lua-plugin-doc*
Provide vimdoc (see |help-writing|), so that users can read your plugin's
documentation in Nvim, by entering `:h {plugin}` in |command-mode|.
------------------------------------------------------------------------------
Tools *lua-plugin-documentation-tools*
DOCUMENTATION TOOLS
- panvimdoc https://github.com/kdheepak/panvimdoc
vim:tw=78:ts=8:sw=4:sts=4:et:ft=help:norl: