Definition: The `/`.babelrc` file, or .babelrc, is a configuration file used by some JavaScript libraries to manage babel plugins in your project. It's located in the src folder under the `plugins` directory within each package.
This file contains various settings that specify where and how to load babel plugins. Hereβs an overview of its most commonly used configurations:
1.
Global Configuration:
- The key `'babel-loader'`: This setting specifies which plugins to use, like `babel-polyfill` for polyfills.
- The value `'main'`: This tells the loader to load only this module's 'js' file.
2.
Global Module Configuration:
- The key `'bundledModules'`: This configures whether modules are bundled or imported by default (bundled).
3.
Imported Modules Configuration:
- The key `'importHelpers'`: This sets whether to use 'babel-preset-env' as an import helper for JSX.
- The value `'none'` is the default setting, meaning no custom babel configuration is used.
4.
Polyfill Configuration:
- The key `'polyfills'`: This defines which modules are polyfilled (used in importing). It's typically set to `'undefined'` if it doesn't need polyfills.
5.
Context Configurations:
- The key `'contextDependencies'`: This configures whether dependencies are context-sensitive or not. Setting this to `true` means all context-specific dependencies will be used.
6.
Custom Configurations (Optional):`
- The keys `'bundledDependencies'` and `'importHelpers'` allow for custom settings if you want to customize how babel is configured for a specific module or package.
Definition:
- `.babelrc`: This is the .babelrc file.
- `babel-loader`: Specifies the plugins used by babel. This could be `babel-polyfill`, `babel-plugin-react-hot-loader` (for hot reloading), etc.
- `'main'`: Specifies which module to load in this configuration file (`js`).
- `'bundledModules'`: Whether modules are bundled or imported by default.
- `'importHelpers'`: If true, imports 'babel-preset-env' as an import helper for JSX.
- `'polyfills': `'undefined'`: The type of polyfills to use. This could be `'none'` (no custom babel configuration) or `'jsx'` (use `babel-preset-es2015') if you want to force polyfill usage in JSX.
- `'contextDependencies'`: If true, all context-specific dependencies will be used.
Understanding this file is crucial for setting up your project's babel plugin configuration.
/.babelrc