Awesome
Community Maintained
We rely on your help to keep this project up to date and work with the latest versions of craco
and react-scripts
.
Before you send a PR, please check the following:
- 100% test coverage
yarn test
- Code is formatted with Prettier
yarn format
- No ESLint warnings
yarn lint
- No security vulnerabilities in any NPM packages
yarn audit
You are also welcome to add your GitHub username to the Contributors section at the bottom of this README. (optional)
Please don't send a pull request if it does not meet the above requirements
Pull requests will be ignored and closed if there is a failing build on Travis CI.
Craco Less Plugin
This is a craco plugin that adds Less support to create-react-app version >= 2.
Use react-app-rewired for
create-react-app
version 1.
Ant Design
If you want to use Ant Design with create-react-app
,
you should use the craco-antd
plugin.
craco-antd
includes Less and babel-plugin-import
(to only include the required CSS.) It also makes it easy to customize the theme variables.
Supported Versions
craco-less
is tested with:
react-scripts
:^5.0.1
@craco/craco
:^7.1.0
Installation
First, follow the craco
Installation Instructions to install the craco
package, create a craco.config.js
file, and modify the scripts in your package.json
.
Then install craco-less
:
$ yarn add -D craco-less
# OR
$ npm i -D craco-less
Usage
Here is a complete craco.config.js
configuration file that adds Less compilation to create-react-app
:
const CracoLessPlugin = require("craco-less");
module.exports = {
plugins: [{ plugin: CracoLessPlugin }],
};
Configuration
You can pass an options
object to configure the loaders and plugins(configure less and less modules at the same time). You can also pass a modifyLessRule
(or modifyLessModuleRule
) callback to have full control over the Less webpack rule.
options.styleLoaderOptions
- Default:
{}
- View the
style-loader
options
- Default:
options.cssLoaderOptions
- Default:
{ importLoaders: 2 }
- View the
css-loader
options
- Default:
options.postcssLoaderOptions
- Default:
{ ident: "postcss", plugins: () => [ ... ] }
- View the
postcss-loader
options
- Default:
options.lessLoaderOptions
- Default:
{}
- View the
less-loader
documentation - View the Less options
- You must use "camelCase" instead of "dash-case", e.g.
--source-map
=>sourceMap
- You must use "camelCase" instead of "dash-case", e.g.
- Default:
options.miniCssExtractPluginOptions
(only used in production)- Default:
{}
- View the
mini-css-extract-plugin
documentation
- Default:
options.modifyLessRule(lessRule, context)
- A callback function that receives two arguments: the webpack rule, and the context. You must return an updated rule object.
lessRule
:test
: Regex (default:/\.less$/
)exclude
: Regex (default:/\.module\.less$/
)use
: Array of loaders and options.sideEffects
: Boolean (default:true
)
context
:env
: "development" or "production"paths
: An object with paths, e.g.appBuild
,appPath
,ownNodeModules
- A callback function that receives two arguments: the webpack rule, and the context. You must return an updated rule object.
options.modifyLessModuleRule(lessModuleRule, context)
- A callback function that receives two arguments: the webpack rule, and the context. You must return an updated rule object.
lessModuleRule
:test
: Regex (default:/\.module\.less$/
)use
: Array of loaders and options.
context
:env
: "development" or "production"paths
: An object with paths, e.g.appBuild
,appPath
,ownNodeModules
- A callback function that receives two arguments: the webpack rule, and the context. You must return an updated rule object.
For example, to configure less-loader
:
const CracoLessPlugin = require("craco-less");
module.exports = {
plugins: [
{
plugin: CracoLessPlugin,
options: {
lessLoaderOptions: {
lessOptions: {
modifyVars: {
"@primary-color": "#1DA57A",
"@link-color": "#1DA57A",
"@border-radius-base": "2px",
},
javascriptEnabled: true,
},
},
},
},
],
};
CSS / Less Modules
CSS / Less modules are enabled by default, and the default file suffix for less modules is .module.less
.
If your project is using typescript, please append the following code to ./src/react-app-env.d.ts
declare module "*.module.less" {
const classes: { readonly [key: string]: string };
export default classes;
}
You can use modifyLessModuleRule
to configure the file suffix and loaders (css-loader, less-loader ...) for less modules.
For example:
const CracoLessPlugin = require("craco-less");
const { loaderByName } = require("@craco/craco");
module.exports = {
plugins: [
{
plugin: CracoLessPlugin,
options: {
modifyLessRule(lessRule, context) {
// You have to exclude these file suffixes first,
// if you want to modify the less module's suffix
lessRule.exclude = /\.m\.less$/;
return lessRule;
},
modifyLessModuleRule(lessModuleRule, context) {
// Configure the file suffix
lessModuleRule.test = /\.m\.less$/;
// Configure the generated local ident name.
const cssLoader = lessModuleRule.use.find(loaderByName("css-loader"));
cssLoader.options.modules = {
localIdentName: "[local]_[hash:base64:5]",
};
return lessModuleRule;
},
},
},
],
};
CSS modules gotcha
There is a known problem with Less and CSS modules regarding relative file paths in url(...)
statements. See this issue for an explanation.
Further Configuration
If you need to configure anything else for the webpack build, take a look at the
Configuration Overview section in the craco
README. You can use CracoLessPlugin
while making other changes to babel
and webpack
, etc.
Contributing
Install dependencies:
$ yarn install
# OR
$ npm install
Run tests:
$ yarn test
Before submitting a pull request, please check the following:
- All tests are passing
- Run
yarn test
- Run
- 100% test coverage
- Coverage will be printed after running tests.
- Check the coverage results in your browser:
open coverage/lcov-report/index.html
- No ESLint errors
yarn lint
- All code is formatted with Prettier
yarn format
- If you use VS Code, you should enable the
formatOnSave
option.
- Using the correct webpack version as a dependency
yarn update_deps
- NOTE: The
webpack
dependency is needed to silence some annoying warnings from NPM. This must always match the version fromreact-scripts
.
Releasing a new version
- Make sure the "Supported Versions" section is updated at the top of the README.
- Check which files will be included in the NPM package:
npm pack
- Update
.npmignore
to exclude any files.
- Release new version to NPM:
npm publish