❗ Version 2.0 has been released with breaking changes! Be sure to check out the migration guide.

Text editing in Neovim with immediate visual feedback: see the effects of any command on your buffer in real-time. Preview macros, the :norm command, and more!

_{Theme: tokyonight.nvim}

In Neovim version 0.8, the command-preview feature was introduced. Despite its name, it does not enable automatic previewing of any command. Instead, users must manually update the buffer text and set highlights for each command they wish to preview.

This plugin addresses that limitation by offering a simple API for creating previewable commands in Neovim. Just specify the command you want to preview and live-command will handle the rest. This includes viewing individual insertions, changes and deletions as you type.

Neovim 0.8+

Install via your favorite package manager and call the setup function:

use {
  "smjonas/live-command.nvim",
  -- live-command supports semantic versioning via Git tags
  -- tag = "2.*",
  config = function()
    require("live-command").setup()
  end,
}

Plug 'smjonas/live-command.nvim'

require("live-command").setup()

The easiest way to use live-command is with the provided :Preview command. For example, :Preview delete will show you a preview of deleting the current line. You can also provide a count or a range to the command, such as :'<,'>Preview norm A;, which shows the effect of appending a semicolon to every visually selected line.

For a more convenient experience, live-command allows you to define custom previewable commands. This can be done by passing a list of commands to the setup function. For instance, to define a custom :Norm command that can be previewed, use the following:

require("live-command").setup {
  commands = {
    Norm = { cmd = "norm" },
  },
}

Each command you want to preview needs a name (which must be uppercase) and an existing command to run on each keypress, specified via the cmd field.

If you wish to customize the plugin, supply any settings that differ from the defaults to the setup function. The following shows the default options:

require("live-command").setup {
  enable_highlighting = true,
  inline_highlighting = true,
  hl_groups = {
    insertion = "DiffAdd",
    deletion = "DiffDelete",
    change = "DiffChange",
  },
}

enable_highlighting: boolean

Default: true

Determines whether highlights should be shown. If false, only text changes are shown, without any highlights.

inline_highlighting: boolean

Default: true

If true, differing lines will be compared in a second run of the diff algorithm to identify smaller differences. This can result in multiple highlights per line. If set to false, the whole line will be highlighted as a single change.

hl_groups: table<string, string|boolean>

Default: { insertion = "DiffAdd", deletion = "DiffDelete", change = "DiffChange" }

A table mapping edit types (insertion, deletion or change) to highlight groups used for highlighting buffer changes. This table is merged with the defaults, allowing you to omit any keys that match the default. If a value is set to false, no highlights will be shown for that type. If hl_groups.deletion is false, deletion edits will not be undone, so deleted text won't be highlighted.

Like this project? Give it a ⭐ to show your support!

Also consider checking out my other plugin inc-rename.nvim, which is optimized for live-renaming with LSP.