ansi.nvim

A Neovim plugin that renders ANSI color escape codes as actual colors in buffers using concealer.

Features

• Renders ANSI escape sequences as actual colors
• Uses Neovim's concealer to hide escape codes
• Supports foreground and background colors
• Supports text attributes (bold, italic, underline)
• Real-time highlighting updates as you edit
• Configurable auto-enable for specific filetypes

Installation

Using lazy.nvim

{
  '0xferrous/ansi.nvim',
  config = function()
    require('ansi').setup({
      auto_enable = false,  -- Auto-enable for configured filetypes
      filetypes = { 'log', 'ansi' },  -- Filetypes to auto-enable
    })
  end
}

Using packer.nvim

use {
  '0xferrous/ansi.nvim',
  config = function()
    require('ansi').setup()
  end
}

Using vim-plug

Plug '0xferrous/ansi.nvim'

" In your init.lua or vimrc:
lua require('ansi').setup()

Manual Installation

git clone https://github.com/0xferrous/ansi.nvim.git ~/.local/share/nvim/site/pack/plugins/start/ansi.nvim

Usage

Commands

• :AnsiEnable - Enable ANSI color rendering for current buffer
• :AnsiDisable - Disable ANSI color rendering for current buffer
• :AnsiToggle - Toggle ANSI color rendering for current buffer

Lua API

local ansi = require('ansi')

-- Setup with custom config
ansi.setup({
  auto_enable = true,
  filetypes = { 'log', 'ansi', 'term' }
})

-- Manual control
ansi.enable()    -- Enable for current buffer
ansi.disable()   -- Disable for current buffer
ansi.toggle()    -- Toggle for current buffer

Configuration

require('ansi').setup({
  -- Automatically enable for configured filetypes
  auto_enable = false,
  
  -- Filetypes to auto-enable when auto_enable is true
  filetypes = { 'log', 'ansi' },
  
  -- Color theme: 'classic', 'modern', 'catppuccin', 'dracula', 'onedark', 'gruvbox', 'terminal'
  theme = 'gruvbox',
})

Color Themes

• 'classic' - Traditional ANSI colors (muted, original)
• 'modern' - Modern terminal colors (vibrant, like Windows Terminal)
• 'catppuccin' - Soft pastel colors
• 'dracula' - Dracula theme colors
• 'onedark' - One Dark theme colors
• 'gruvbox' - Gruvbox dark colors (like bat uses)
• 'gruvbox_dark' - Same as 'gruvbox'
• 'gruvbox_light' - Gruvbox light variant
• 'terminal' - Try to use your terminal's actual colors

Supported ANSI Codes

Colors

• Standard colors: black, red, green, yellow, blue, magenta, cyan, white
• Bright colors: bright_black, bright_red, etc.
• Both foreground (30-37, 90-97) and background (40-47, 100-107) colors

Text Attributes

• Bold (1)
• Italic (3)
• Underline (4)
• Reset (0)

Testing

Quick Test

1. Open the provided test file:

   nvim test_ansi.txt

2. Enable ANSI rendering:

   :AnsiEnable

3. You should see colored text with ANSI escape sequences concealed

Generate Test Data

Use the provided script to generate ANSI output:

# Generate test output
./test_script.sh > test_output.log

# Open in Neovim
nvim test_output.log

# Enable ANSI rendering
:AnsiEnable

Manual Testing

Create a buffer with ANSI codes:

[31mThis is red text[0m
[32;1mThis is bold green text[0m
[33;4mThis is underlined yellow text[0m
[34;42mThis is blue text on green background[0m

Then run :AnsiEnable to see the colors rendered.

Development

Running Tests

# Run unit tests
nvim --headless -c "luafile tests/run_tests.lua" -c "qa"

# Run linting
luacheck lua/ --globals vim

# Run style check
stylua --check lua/

CI/CD

The project uses GitHub Actions for continuous integration:

• Tests: Runs on Neovim versions 0.8.3, 0.9.5, 0.10.0, 0.11.3, and nightly
• Linting: Uses luacheck for Lua code analysis
• Style: Uses stylua for code formatting