prettier-loader
Prettier loader for Webpack.
Purpose
Prettier is one of the best tools that really help developers not to waste time on codestyle.
Listed below are some of the ways one could employ prettier in a project:
-
Editor Integration
-
Pros:
- no overhead bootstrapping code
- autoformatting on every save
-
Cons:
- every developer needs to setup and configure editor's plugin manually
- teammates can have conflicting plugin settings that might override default settings in an unpredictable way. Or one could forget to install
node_modules
and a globally installed prettier
will be used instead, which might be of older version, etc. This leads to frustrating hiccups in the workflow and, potentially, bugs.
-
Pre-commit Hook
- Pros:
- works in the background (i.e. developer doesn't have to think about it)
- consistent prettier settings in the project
- Cons:
- you can not see prettier changes on save
-
Watching For Changes
- Pros:
-
no overhead bootstrapping code
-
autoformatting on every save
-
works in the background
-
consistent prettier settings in the project
- Cons:
- if you already have another watcher (e.g.
webpack-dev-server
or watchman
), you'll be wasting resources and your bundler will be triggered twice on every change: first by user, then by prettier formatting
-
CLI
- Cons:
- you can not see prettier changes on save
- prone to errors unless stored somewhere (e.g. npm-scripts)
-
This Webpack Loader
- Pros:
-
autoformatting on every save (if working with webpack-dev-server)
-
works in the background
-
consistent prettier settings in the project
-
updates all the codebase when new prettier version is released
- Cons:
- works only on webpack-dependent projects
In short, idea is to make source code auto-prettier
-fy on every save. But to do it in a cross-IDE manner. Use of webpack
, eliminates the need to install and configure plugins on each developer's machine and also provides better efficency, as no other watchers are needed.
Features
- support prettier configuration files:
.prettierrc
, prettier.config.js
, "prettier"
key in your package.json
file - support of ignoring code using both comments and
.prettierignore
file - override configuration files in loader options
- zero configuration of loader options for supporting all features out of the box
Requirements
- webpack >= 2
- prettier >= 1.6
Create an issue on pr, if you really need to support Webpack 1.
Installation
npm install prettier-loader prettier --save-dev
Usage
Minimal config example
module.exports = {
module: {
rules: [
{
test: /\.jsx?$/,
use: {
loader: 'prettier-loader',
exclude: /node_modules/,
}
}
]
}
};
Full config example with description
module.exports = {
module: {
rules: [
{
test: /\.jsx?$/,
use: {
loader: 'prettier-loader',
enforce: 'pre',
exclude: /node_modules/,
options: {
trailingComma: 'es5',
tabWidth: 4,
resolveConfigOptions: {
editorconfig: true,
config: 'config/prettier.config.js'
},
skipRewritingSource: false,
ignoreInitial: false,
},
}
}
]
}
};
Working with HTML preprocessor
If you work with HTML preprocessor (Twig, EJS, Nunjucks, ...), you may want to process the output stream.
Still you don't want the input template to be rewritten with the output.
In that case, you'll need to tell the loader to keep the source file unchanged.
module.exports = {
module: {
rules: [
{
test: /\.njk?$/,
use: [
{
loader: 'html-loader',
},
{
loader: 'prettier-loader',
options: {
skipRewritingSource: true,
},
},
{
loader: 'nunjucks-html-loader',
},
],
}
]
}
};
Pro Tip
Install and use it only in development environment if you minimize code for production, don't do unnecessary work!
Known issue
As a loader, that is modifying source code, it has known issue with double compilation in watch mode. With current webpack
API this problem can not be solved (the same problem exists in other similar projects). Webpack maintainers are not going to help with this.
Contributing
All pull requests that respect next rules are welcome:
-
Before opening pull request to this repo run npm t
to lint, prettify and run test on code.
-
All bugfixes and features should contain tests.
License
MIT License
Copyright (c) 2017 Oleg Repin
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.