Prettier_d NPM

prettier_d

Makes prettier the fastest formatter on the planet. Additional options include:

--pkg-conf: Read prettier configuration from .prettierrc, package.json, or .editorconfig
--json: Format JSON with json-stable-stringify and json-align
--keep-indentation: Preserve the indentation of the first line
--fallback: Return original input if it cannot be parsed (useful for editor integrations)
--local-only: Force ./node_modules/prettier to be used

"But prettier is pretty fast already, right?"
Install
Usage
How does this work?
Commands
Configuration file
Editor integration
- Real-time formatting in Vim
Moar speed
Compatibility
Limitations

"But prettier is pretty fast already, right?"

Yes, it's actually super fast. But the node.js startup time and loading all the required modules slows down formatting times. prettier_d reduces this overhead by running a server in the background. It brings the formatting time down from 0.25 seconds to 0.1 seconds on a 3265 byte file (down to 0.04 seconds using the prettier_dnc tool). If you want to format from within your editor whenever you save a file, prettier_d is for you.

Install

This will install the prettier_d command globally:

yarn global add prettier_d
# or
npm install -g prettier_d

Usage

To start the server and format a file, just run:

prettier_d file.js

On the initial call, the prettier_d server is launched and then the given file is formatted. Subsequent invocations are super fast.

How does this work?

The first time you use prettier_d, a little server is started in the background and bound to a random port. The port number is stored along with a token in ~/.prettier_d. You can then run prettier_d commands the same way you would use prettier and it will delegate to the background server. It will load a separate instance of prettier for each working directory to make sure settings are kept local. If prettier is found in the current working directory's node_modules folder, then this version of prettier is going to be used. Otherwise, the version of prettier that ships with prettier_d is used as a fallback.

When you have a lot of projects that use prettier, it might use quite a bit of ram for cached instances. All memory can be freed up by running prettier_d stop or prettier_d restart.

Commands

Control the server like this:

prettier_d <command>

Available commands:

start: start the server
stop: stop the server
status: print out whether the server is currently running
restart: restart the server
[options] file.js file.js: invoke prettier with the given options. The prettier engine will be created in the current directory. If the server is not yet running, it is started.

prettier_d will select a free port automatically and store the port number along with an access token in ~/.prettier_d.

Type prettier_d --help to see the supported prettier options. Here are the options supported by the bundled version of prettier:

Usage: prettier_d [opts] [filename]

Available options:
  --write                  Edit the file in-place. (Beware!)
  --list-different or -l   Print filenames of files that are different from Prettier formatting.
  --stdin                  Read input from stdin.
  --print-width <int>      Specify the length of line that the printer will wrap on. Defaults to 80.
  --tab-width <int>        Specify the number of spaces per indentation-level. Defaults to 2.
  --use-tabs               Indent lines with tabs instead of spaces.
  --no-semi                Do not print semicolons, except at the beginning of lines which may need them.
  --single-quote           Use single quotes instead of double quotes.
  --no-bracket-spacing     Do not print spaces between brackets.
  --jsx-bracket-same-line  Put > on the last line instead of at a new line.
  --trailing-comma <none|es5|all>
                           Print trailing commas wherever possible. Defaults to none.
  --parser <flow|babylon>  Specify which parse to use. Defaults to babylon.
  --no-color               Do not colorize error messages.
  --version or -v          Print Prettier version.


Options specific to prettier_d:
  --fallback               If formatting fails, print the original input. Defaults to false.
  --json                   Try to parse input as JSON and format with json-stable-stringify and json-align. Defaults to false.
  --local-only             Fail if prettier is not in ./node_modules. Defaults to false.
                           If --json is specified, it will still be formatted.
                           If --fallback is specified, the original input will be printed.
  --pkg-conf               Read prettier configuration from nearest package.json/.prettierrc/.editorconfig to working directory.
                           If a .prettierrc file is found, it will override package.json.
                           Both .prettierrc and package.json override .editorconfig.
                           NOTE: CLI options pertaining to formatting will be ignored.
  --keep-indentation       Keep input indentation (read from first line).
                           NOTE: This will mangle multiline literals (e.g. template strings).
                           NOTE: This does not work with JSON.

Configuration file

In the spirit of https://github.com/prettier/prettier/issues/918, the --pkg-conf option uses the prettier configuration read from the nearest .prettierrc, package.json, or .editorconfig file.

`.prettierrc`

If .prettierrc is present, it's expected to be JSON, for example:

{
  "printWidth": 80,
  "tabWidth": 2,
  "singleQuote": true,
  "trailingComma": "es5",
  "bracketSpacing": true,
  "semi": false
}

`package.json`

If package.json is present, its prettier key is expected to have the same format as .prettierrc above. For example:

{
  "prettier": {
    "useTabs": false,
    "printWidth": 80,
    "tabWidth": 2,
    "singleQuote": false,
    "trailingComma": "none",
    "bracketSpacing": true,
    "jsxBracketSameLine": false,
    "parser": "babylon",
    "semi": true
  }
}

`.editorconfig`

If .editorconfig is present, the following properties are parsed into prettier options:

indent_style
tab_width
max_line_length

Note that a .prettierrc file will override a package.json file, and both will override .editorconfig. Also, these files are cached, so if you change them, you'll need to restart the server for the changes to apply: prettier_d restart

Editor integration

See https://github.com/prettier/prettier#editor-integration

Real-time formatting in Vim

If you use Vim, and you'd like prettier_d to format your code as you type, install Neoformat and add this to your ~/.vimrc:

autocmd FileType javascript setlocal formatprg=prettier_dnc\ --local-only\ --pkg-conf\ --fallback
autocmd BufWritePre,TextChanged,InsertLeave *.js Neoformat

" Use formatprg when available
let g:neoformat_try_formatprg = 1
" https://github.com/sbdchd/neoformat/issues/25
let g:neoformat_only_msg_on_error = 1

Then, make sure you've started the server: prettier_d start.

If you're in a repository that has prettier in its node_modules/, this will format your code:

before each save
whenever text is changed in normal mode
whenever you leave insert mode

The prettier configuration is read from .prettierrc, package.json, or .editorconfig, if available. Otherwise, the default prettier configuration is used. If you'd prefer a different configuration, replace --pkg-conf with your own options.

Moar speed

If you're really into performance and want the lowest possible latency, talk to the prettier_d server with netcat. This will also eliminate the node.js startup time.

PORT=`cat ~/.prettier_d | cut -d" " -f1`
TOKEN=`cat ~/.prettier_d | cut -d" " -f2`
echo "$TOKEN $PWD file.js" | nc -q 0 127.0.0.1 $PORT

# You can also pipe a stream in with `--stdin`:
cat file.js | cat <(echo "$TOKEN $PWD --stdin") - | nc -q 0 127.0.0.1 $PORT
# `prettier_dnc` is provided as a helper script for this usage:
cat file.js | prettier_dnc

This runs prettier even faster!

Compatibility

prettier_d ^5.0.0: prettier ^1.0.0

Limitations

Multiple files are currently not supported. You can use e.g. xargs to work around this: ls *.js | xargs -n1 prettier_d
The CLI output is not quite the same as prettier. Don't worry, the source code formatting still is!