Dart Support for Vim

dart-vim-plugin provides filetype detection, syntax highlighting, and indentation for Dart code in Vim.

Looking for auto-complete, diagnostics as you type, jump to definition and other intellisense features? Try a vim plugin for the Language Server Protocol such as vim-lsc configured to start the Dart analysis server with the --lsp flag.

Looking for an IDE experience? See the Dart Tools page.

Commands

:DartFmt

Installation

Install as a typical vim plugin using your favorite approach. If you don't have a preference vim-plug is a good place to start. Below are examples for common choices, be sure to read the docs for each option.

vim-plug

call plug#begin()
"... <snip other plugins>
Plug 'dart-lang/dart-vim-plugin'

call plug#end()

Then invoke :PlugInstall to install the plugin.

pathogen

Clone the repository into your pathogen directory.

mkdir -p ~/.vim/bundle && cd ~/.vim/bundle && \
git clone https://github.com/dart-lang/dart-vim-plugin

Ensure your .vimrc contains the line execute pathogen#infect()

vundle

set rtp+=~/.vim/bundle/Vundle.vim
call vundle#begin()
"... <snip other plugins>
Plugin 'dart-lang/dart-vim-plugin'

call vundle#end()

Configuration

Enable HTML syntax highlighting inside Dart strings with let dart_html_in_string=v:true (default false).

Highlighting for specific syntax groups can be disabled by defining custom highlight group links. See :help dart-syntax

Enable Dart style guide syntax (like 2-space indentation) with let g:dart_style_guide = 2

Enable DartFmt execution on buffer save with let g:dart_format_on_save = 1

Configure DartFmt options with let g:dartfmt_options (discover formatter options with dartfmt -h)

Why doesn't the plugin indent identically to dart format?

The indentation capabilities within vim are limited and it's not easy to fully express the indentation behavior of dart format. The major area where this plugin differs from dart format is indentation of function arguments when using a trailing comma in the argument list. When using a trailing comma (as is common in flutter widget code) dart format uses 2 space indent for argument parameters. In all other indentation following an open parenthesis (argument lists without a trailing comma, multi-line assert statements, etc) dart format uses 4 space indent. This plugin uses 4 space indent indent by default. To use 2 space indent by default, let g:dart_trailing_comma_indent = v:true.

How do I configure an LSP plugin to start the analysis server?

The Dart SDK comes with an analysis server that can be run in LSP mode. The server ships with the SDK. Assuming the bin directory of the SDK is at $DART_SDK the full command to run the analysis server in LSP mode is $DART_SDK/dart $DART_SDK/snapshots/analysis_server.dart.snapshot --lsp. If you'll be opening files outside of the rootUri sent by your LSP client (usually cwd) you may want to pass onlyAnalyzeProjectsWithOpenFiles: true in the initializationOptions. See the documentation for your LSP client for how to configure initialization options. If you are using the vim-lsc plugin there is an additional plugin which can configure everything for you at vim-lsc-dart. A minimal config for a good default experience using vim-plug would look like:

call plug#begin()
Plug 'dart-lang/dart-vim-plugin'
Plug 'natebosch/vim-lsc'
Plug 'natebosch/vim-lsc-dart'
call plug#end()

let g:lsc_auto_map = v:true