mini-extract-plugin


!Dependencies

---

Generalized and hookable
mini-css-extract-plugin.
Extract any format, process it your way.

#### 🏠 Homepage | 🗃 Repository | 📦 NPM | 📚 Documentation | 🐛 Issue Tracker

🪑 Table of Content

- 🧰 Features
- 👶 Install
- 🚀 Usage
- Minimal setup
- Subclassing
- Instance options
- Helpers
- Typing
- Debugging
- 🔮 Background
- 🤖 API
- Options
- Hooks order
- Hooks
- Contexts
- ⏳ Changelog
- 🛠 Developing
- 🏗 Roadmap
- 🤝 Contributing
- 🧙 Contributors
- ⭐ Show your support
- 🐙 Community
- 🔗 Related Projects
- 👨‍🔧 Maintainers
- 📝 License

🧰 Features

- Exposes 18 hooks that enable you to:

- Override how the modules are parsed when passed to the loader
- Override how the modules are merged into a common file
- Override what content is returned instead of the content was extracted.
- Define if and how the modules should should be split
- Hook into the compiler / compilation.
- Extend initialization

- Based on
mini-css-extract-plugin
v0.9.0, this package recycles the same logic, but allows you override the
format-specific logic and more.

- See how the original mini-css-extract-plugin has been
reimplemented using this package.

👶 Install

``sh
npm install mini-extract-plugin
`

🚀 Usage

$3

For a minimal setup, just import the plugin and give it a unique type name by
which the plugin will be known. The instances of the created class can be used
in Webpack.

`ts
// Default import is a class factory
import mep from 'mini-extract-plugin';
// or const mep = require('mini-extract-plugin').default

// Minimal config
const MyMiniExtractPlugin = mep({
type: 'my-custom-type'
});

// Create instance to be used in the config.
// Class constructor optionally accepts an options object
const myMEP = new MyMiniExtractPlugin({
...
});

// webpack config
const config = {
...
module: {
rules: [
{
// We want all encountered files named "*.some.json"
// to be extracted into separate files.
//
// The files could be e.g. i18n files, or some config
// files that are defined in multiple places but we want
// a single file that combines all matched files.
resourceQuery: /\.some\.json$/,
use: [
// Register the plugin as a loader
// asLoader is an object so we have to use it in the
// use array
myMEP.asLoader,
],
...
}
],
},
plugins: [
// Register the plugin as a plugin.
myMEP,
...
]
}
`

However, this example above is not terribly useful since we haven't specified
any hooks. That means, for example, that found JSONs will be concatenated into
as single file as strings (e.g. "{}" + "{}"), but that won't yield a valid
JSON. So to make the new plugin class to work properly, we need to speficy more
than just the type.

`ts
import mep from 'mini-extract-plugin';
// const mep = require('mini-extract-plugin').default

const MyMiniExtractPlugin = mep({
type: 'my-custom-type',
displayName: My Super Awesome Extract Plugin,
hooks: [
// Tap sync function compilationHookFn into compilation
// hook.
// Maybe we want to tap into the Webpack's Compilation
// instance
{
name: 'compilation',
type: 'tap',
hooks: [compilationHookFn],
},
// Tap sync function mergeHookFn into merge hook.
// Here we will override how the modules should be
// concatenated (instead of string concat, we join JSONs
// as objects)
{ name: 'merge', type: 'tap', hooks: [mergeHookFn] },
],
});

// Create instance to be used in the config.
const myMEP = new MyMiniExtractPlugin();
...
`

This is better! We have specified how the modules should be merged and so when
we use this plugin in the Webpack now, the end result will be a proper JSON.

This way, you can override only the parts of the process that needs to be
modified. You can also tap multiple functions into any single hook. And where
available, you can also tap asynchronously. Some hooks are "waterfall", meaning
that result from one function is passed to another. Other are regular hooks
where the tapped functions don't interact. See
tapable
for details on how hooks work.

For details on what hooks are available, their signatures, whether they're sync
or async, etc, see Hooks.

You may have noticed that we've also specified a displayName property.
Additional options allow you to:

- override what classes should be used for modules, dependencies, and other
Webpack entities (useful if you want to pass custom data along with the
modules).
- override what options can be passed to the class constructor when creating a
plugin instance (by default,
mini-css-extract-plugin
options are used)
- override the name of the created class, and how it is displayed.

See full description of the class options here.

#### Examples

- mini-css-extract-plugin fixture -
Test re-implementation of
mini-css-extract-plugin
- mini-i18n-extract-plugin -
Extract i18n files (JSON / YAML) and split the files by entrypoints and language locales.

$3

#### Class factory

Here's an example how MiniExtractPlugin can be subclassed taken from the mini-css-extract-plugin replimenetation

`ts
import miniExtractPluginFactory, { types } from 'mini-extract-plugin';
import Module from './module';
import ModuleFactory from './module-factory';
import Dependency from './dependency';
import DependencyTemplate from './dependency-template';
import hooks from './hooks';
import { type, typeReadable } from './config';

const MiniExtractPluginClass = miniExtractPluginFactory<{
dependencyClass: types.DependencyClass;
moduleClass: types.ModuleClass;
moduleFactoryClass: typeof ModuleFactory;
}>({
type,
displayName: My Mini ${typeReadable} Extract Plugin,
moduleFactoryClass: ModuleFactory,
dependencyClass: Dependency,
dependencyTemplateClass: DependencyTemplate,
hooks: [
{ name: 'compilation', type: 'tap', hooks: [hooks.compilation!] },
{ name: 'merge', type: 'tap', hooks: [hooks.merge!] },
],
});

export default MiniExtractPluginClass;
`

The factory function is passed:

- identifiers type and optional displayName.
- custom subclasses dependencyClass, moduleClass, and
dependencyTemplateClass.
- compilation and merge hooks.

Factory function was also given an object as a type parameter. This object specifies which types should be used for classes and options, and enable type inferrence for subclasses with custom classes and options.

Full list of type options with their defaults:

`ts
const MyMiniExtractPlugin = miniExtractPluginFactory<{
// These reflect the types of the classes that we pass to the
// class factory as options.
dependencyClass?: DependencyClass;
dependencyTemplateClass?: DependencyTemplateClass;
moduleClass?: ModuleClass;
moduleFactoryClass?: ModuleFactoryClass;
// Type of the options object passed to constructor on instantiations.
constructorOptions?: { [key: string]: any };
} = {}
>(...)
`

#### Options classes

Classes that can be passed to the factory function can be found at the root of
the export. Subclassing is as simple as:

`ts
import {
Dependency,
DependencyTemplate,
Module,
ModuleFactory,
} from 'mini-extract-plugin';

class DependencySubclass extends Dependency {}
class DependencyTemplateSubclass extends DependencyTemplate {}
class ModuleSubclass extends Module {}
class ModuleFactorySubclass extends ModuleFactory {}
`

If you use TypeScript and want to override the types these subclass use in methods / constructor, you can pass type arguments. This is useful e.g. if your subclass adds properties, and you want TypeScript to recognize those properties.

All type parameters that can be passed to classes + their defaults:

`ts
import {
subclassDependency,
subclassDependencyTemplate,
subclassModule,
subclassModuleFactory,
} from 'mini-extract-plugin';

class DependencySubclass extends Dependency<{
// Options object passed to the Dependency constructor
dependencyOptions: DependencyOptions;
}> {}

// subclassDependencyTemplate has no type parameters
class DependencyTemplateSubclass extends DependencyTemplate {}

class ModuleSubclass extends Module<{
// Dependency class whose instance is passed to the Module
// constructor
dependency: Dependency;
}> {}

class ModuleFactorySubclass extends ModuleFactory<{
// Dependency class that is passed to ModuleFactory.create
dependency: Dependency;
// Module class whose instance is created in ModuleFactory.create
// from Dependency
module: Module;
}> {}
`

#### Subclassing helpers

If you need to subclass any of the above but don't need to override the behaviour,
you can use helper subclassing functions.

Each of them accepts options

`ts
import {
subclassDependency,
subclassDependencyTemplate,
subclassModule,
subclassModuleFactory,
} from 'mini-extract-plugin';

// type is the same type argument passed to class factory
const DependencySubclass = subclassDependency({ type: 'custom-plugin' });
const DependencyTemplateSubclass = subclassDependencyTemplate({
type: 'custom-plugin',
});
const ModuleSubclass = subclassModule({ type: 'custom-plugin' });
const ModuleFactorySubclass = subclassModuleFactory({
type: 'custom-plugin',
moduleClass: MyCustomModule, // Optionally define module class
});
`

If you use TypeScript and want to override the classes these subclass use, you can pass type arguments. The type arguments passed to subclass helpers are same as to the classes.

Given the example from above, if you want to module type created by ModuleFactorySubclass to match MyCustomModule, you can do following:

`ts
const ModuleFactorySubclass = subclassModuleFactory<{
module: Module;
}({
type: 'custom-plugin',
moduleClass: MyCustomModule,
});
`

All type parameters that can be passed to helper functions + their defaults:

`ts
import {
subclassDependency,
subclassDependencyTemplate,
subclassModule,
subclassModuleFactory,
} from 'mini-extract-plugin';

const DependencySubclass = subclassDependency<{
// Options object passed to the Dependency constructor
dependencyOptions: DependencyOptions;
}>(...);

// subclassDependencyTemplate has no type parameters
const DependencyTemplateSubclass = subclassDependencyTemplate(...);

const ModuleSubclass = subclassModule<{
// Dependency class whose instance is passed to the Module
// constructor
dependency: Dependency;
}>(...);

const ModuleFactorySubclass = subclassModuleFactory<{
// Dependency class that is passed to ModuleFactory.create
dependency: Dependency;
// Module class whose instance is created in ModuleFactory.create
// from Dependency
module: Module;
}>(...);
`

See how classes are extended in the
re-implementation of mini-css-extract-plugin.

$3

By default, instances of the subclassed MiniExtractPlugin accept an options object with the same options as mini-css-extract-plugin v.0.9.0.

> :warning: Some options, while having same name and fulfilling same task,
> accept different values than those of
> mini-css-extract-plugin. These are:

#### moduleFilename

The function signature is changed to:

(RenderContext, TemplateOptions,
[Module[]](https://github.com/webpack/webpack/blob/96142f829f7df4bfe6aa5095b1aed647de50edfe/lib/Module.js))
=> string;

| Argument | Description |
| ---------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| RenderContext | Context available on Compilation's renderManifest hook. See RenderContext for details. |
| TemplateOptions | Object with info on the chunk that is being rendered:
{
  chunk: Chunk,
   hash: string,
   contentHashType: string
} |
| Module | Module that are being rendered. Modules are of the class as specified in the plugin's class options. |

$3

The package also exposes a util export, which contains utility modules used
for working with the hooks or objects passed to hook functions:

- util.module includes helper functions for working with modules.
- util.subclass includes helper functions for subclassing the classes that
can be passed to the class factory. Use these functions if you need a
subclass but don't care about implementation.

$3

This project is written in TypeScript and the typings are included under the
types import.

- types, the root, includes interfaces related to subclassing
(MiniExtractPlugin, class factory options, etc.)
- types.context includes interfaces for the contexts passed to
tapped functions
- types.hook includes types related to Hooks (Hook overrides, types of
recognized hooks, etc.)
- types.webpack is a shim for Webpack, it includes types that either are not
exposed in Webpack v4, or which have modified interfaces in the extraction
process, so the provided types reflect the actual interface.
- types.util includes helper types which may or may not be useful when
working with the hooks.

What you will most likely want is to have the hook functions types inferred.
You can use the types.hook.Taps interface, which is an object of
{ [hookName]: hookFunction }.
If you want to define only some hooks, use types.hook.PartialTaps.

Both types accept MiniExtractPlugin interface as a type parameter. Use it to have correct types for arguments and return functions. The passed interface affects the inferred types of context objects, classes passed to MiniExtractPlugin (module, dependency, moduleFactory, ...).

`ts
import { types } from 'mini-extract-plugin';

import { IMyMiniExtractPlugin } from './types'

const hooks: types.hook.PartialTaps = {
// Arguments of dependency are inferred thanks to
// PartialTaps
dependency: (context, {exports: exported}) => {
const { childCompilation, classOptions } = context;
...
};
`

$3

This project uses debug. To show debug
logs, activate debug for mini-extract-plugin.

CLI example:

`sh
DEBUG=mini-extract-plugin node path/to/my/mini-extract-plugin-project
`

🔮 Background

mini-css-extract-plugin
is great because it allows you to have modularized definitions, which are then
merged or split as necessary for you during the build.

This is important for bundle optimization, but also for maintainability, as you
can keep the information where it makes sense, without making a tradeoff in
logistics.

When working with Vue, I was hoping to manage other auxiliary file types (i18n
and documentation, to be specific) in a similar manner - modularized definition
but processed and emitted as separate files during build.

There's (understandably) not as much support for other file formats as there is
for CSS. But since other formats could benefit from same action,generalizing
the process was in order (and thus encouraging modularized approach for more
formats).

🤖 API

TypeDoc documentation can be
found here.

$3

`ts
interface ClassOptions {
type: string;
pluginName?: string;
displayName?: string;
className?: string;
moduleType?: string;
pluginOptionsSchema?: any;
loaderOptionsSchema?: any;
dependencyTemplateClass?: DependencyTemplateClass;
dependencyClass?: DependencyClass;
moduleFactoryClass?: ModuleFactoryClass;
moduleClass?: ModuleClass;
hooks?: Overrides;
}
`

The class factory accepts an object with following options:

- type - _(Required)_ Namespace used by this class to distinguish it, its
instances, and webpack resources (e.g. modules and dependencies) from other
MiniExtractPlugin classes.
- E.g. MiniCssExtractPlugin uses css, MiniI18nExtractPlugin uses i18n
- pluginName - Name of plugin used in identifiers. Prefer package-like
(kebab-case) format.
- Default: mini-${type}-extract-plugin.
- displayName - String to be used when printing the class in logging messages
or similar.
- Default: Mini ${type} Extract Plugin where type is capitalized.
- className - Name of the plugin class that is shown when calling either
class.toString() or class.name.
- Default: Mini${type}ExtractPlugin where type is capitalized.
- moduleType - Identifier used to find modules processed by the class.
- Default: ${type}/mini-extract.
- pluginOptionsSchema - JSON schema used to validate options passed to
constructor and used in loader methods.
- Default: MiniCssExtractPlugin's
plugin options schema
- loaderOptionsSchema - JSON schema used to validate options passed to
constructor and used in plugin methods.
- Default: MiniCssExtractPlugin's
plugin options schema
- dependencyTemplateClass - Class that implements Webpack's
DependencyTemplate
interface.
- The instance of dependencyTemplateClass must have a method apply.
- Default: Default is empty implementation.
(see source file).
- dependencyClass - Class that implements Webpack's
Dependency
interface.
- Dependencies are used among other to pass data to Modules. Data passed to
Dependency constructor can be overriden in dependency hook.
- If providing ypur own Dependency class, be sure to subclass the default
implementation to ensure the plugin works as expected. See the
re-implementation of MiniCssExtractPlugin
for an example of how the Dependency class can be extended.
- Default: Default implementation ensures the MiniExtractPlugin works
correctly. It stores information on MiniExtractPlugin type, identifier,
context, and content
(see source file).
- moduleFactoryClass - Class that implements Webpack's
Module Factory
interface.
- The instance of moduleFactoryClass must have a method create that is
called with data and callback and must call the callback with either an
error as first argument or
Module
instance as second argument. The data contains an array-wrapped dependency of
class dependencyClass.
- Default: Default implementation passed the dependency to Module constructor
(see source file).
If moduleClass is specified, the created Module will be of class
moduleClass. Otherwise Webpack's Module class
is used.
- moduleClass - Class that implements Webpack's
Module
interface.
- This class used only with the default moduleFactoryClass
implementation. If you specify moduleFactoryClass, this option is
ignored.
- Module constructor accepts a dependency of class dependencyClass.
- If providing your own Module class, be sure to subclass the default
implementation to ensure the plugin works as expected. See the
re-implementation of MiniCssExtractPlugin
for an example of how the Module class can be extended.
- Default: Default implementation ensures the MiniExtractPlugin works
correctly, and it updates identifiers and hashes
(see source file).
- hooks - Array of objects specifying which Tapable hooks should be tapped
with what functions, and how the hook should behave (sync/async). See
Hooks for the list of available hooks.

- Each object is expected to implement the hook
Override
interface:

| Property | Description | Type | Default |
| -------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | ------------ | ------- |
| name | Name of the hook to be tapped. | string | - |
| type | How should be the functions applied to the hook. These are the methods defined by tapable

Options: 'tap' \| 'tapAsync' \| 'tapPromise' \| 'intercept'

Note: tapAsync and tapPromise are available only for async hooks. See tapable documentation for details. | string | - |
| hooks | Array of functions that should be applied to the hook.

Functions are expected to conform to the hook signature they are tapping to. For details on using sync- / promise- / callback-style functions, see tapable documentation.

See how the hooks are defined in MiniCssExtractPlugin re-implementation. | Function[] | [] |

$3

Hooks are called in following order:

- _Plugin initialization_
- initialize
- _Plugin.apply is called_
- compiler
- compilation
- _Modules passed to loader: Loader.pitch is called and modules are processed
to dependencies_
- pitch
- childCompiler
- source
- childCompilation
- dependency
- extracted
- _If non-entrypoint chunks are emitted: Render and merge chunks' modules_
- beforeRenderChunk
- renderChunk
- afterRenderChunk
- _If using default renderChunk, specify module merging_
- beforeMerge
- merge
- afterMerge
- _Render and merge entrypoint's modules_
- beforeRenderMain
- renderMain
- afterRenderMain
- _If using default renderMain, specify module merging_
- beforeMerge
- merge
- afterMerge

$3

The available hooks in alphabetical order are
(see source file):

#### afterMerge

- Signature: (RenderContext,
Source) => void

- Hook: SyncHook

- Hook called after Modules were merged into a single Source that will be
emitted into a file.

Use this hook if you want to modify the resulting Source without overriding
the merging process itself, or if you want to trigger some behaviour after
the merge step has finished.

- Default: No behaviour.

| Argument | Description |
| ------------------------------------------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| RenderContext | Context available on Compilation's renderManifest hook. See RenderContext for details. |
| Source | Instance of Webpack's Source (value returned by merge). |

#### afterRenderChunk

- Signature: (RenderContext,
[RenderManifestEntry[]](https://github.com/webpack/webpack/blob/ee94677a7729fac726b7100256986a7a7db8c53e/lib/Template.js#L57))
=> void

- Hook: SyncHook

- Hook called after the list of
RenderManifestEntries
has been prepared for the generation of chunk (non-entrypoint) files.

Use this hook if you want to modify the resulting list of
RenderManifestEntries
without overriding the renderChunk process itself, or if
you want to trigger some behaviour after the renderChunk
step has finished.

- Default: No behaviour.

| Argument | Description |
| ----------------------------------------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| RenderContext | Context available on Compilation's renderManifest hook. See RenderContext for details. |
| RenderManifestEntry | List of Webpack's RenderManifestEntry objects that will be used to render and create output files. (values processed by renderChunk). |

#### afterRenderMain

- Signature: (RenderContext,
[RenderManifestEntry[]](https://github.com/webpack/webpack/blob/ee94677a7729fac726b7100256986a7a7db8c53e/lib/Template.js#L57))
=> void

- Hook: SyncHook

- Hook called after the list of
RenderManifestEntries
has been prepared for the generation of main (entry) files.

Use this hook if you want to modify the resulting list of
RenderManifestEntries
without overriding the renderMain process itself, or if
you want to trigger some behaviour after the renderMain
step has finished.

- Default: No behaviour.

| Argument | Description |
| ----------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| RenderContext | Context available on Compilation's renderManifest hook. See RenderContext for details. |
| RenderManifestEntry | List of Webpack's RenderManifestEntry objects that will be used to render and create output files. (values processed by renderMain). |

#### beforeMerge

- Signature: (RenderContext,
[Module[]](#options)) =>
[Module[]](#options)

- Hook: SyncWaterfallHook

- Hook called when merging multiple Modules into a single Source that will be
emitted into a file.

Use this hook if you want to modify the list of modules without overriding
the merging process itself.

- Default: No modifications done.

| Argument | Description |
| --------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| RenderContext | Context available on Compilation's renderManifest hook. See RenderContext for details. |
| Modules | List of Options.moduleClass modules. |

| Returns | Description |
| --------------------- | ------------------------------------------------------------ |
| Modules | Processed list of Options.moduleClass modules. |

#### beforeRenderChunk

- Signature: (RenderContext,
[Module[]](#options)) =>
[Module[] | Module[][]](#options)

- Hook: SyncWaterfallHook

- Hook called when Webpack is generating a chunk (non-entrypoint file) from
the given set of modules.

Use this hook if you want to modify the list of modules or if you want to
split the list of modules into multiple chunks without overriding the
rendering process itself.

This hook is called only if the extracted Dependencies from
dependency hook were split into chunks by Webpack.

- Default: No modifications done.

| Argument | Description |
| --------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| RenderContext | Context available on Compilation's renderManifest hook. See RenderContext for details. |
| Modules | List of Options.moduleClass modules. |

| Returns | Description |
| --------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| ModulesGroups | List or list of lists of Options.moduleClass modules. If a list of lists is returned, these are interpreted as module groups. Each module group will emit separate chunk file. |

#### beforeRenderMain

- Signature: (RenderContext,
[Module[]](#options)) =>
[Module[] | Module[][]](#options)

- Hook: SyncWaterfallHook

- Hook called when Webpack is generating a main (entry) file from
the given set of modules.

Use this hook if you want to modify the list of modules or if you want to
split the list of modules into multiple groups without overriding the
rendering process itself.

- Default: No modifications done.

| Argument | Description |
| --------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| RenderContext | Context available on Compilation's renderManifest hook. See RenderContext for details. |
| Modules | List of Options.moduleClass modules. |

| Returns | Description |
| --------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| ModulesGroups | List or list of lists of Options.moduleClass modules. If a list of lists is returned, these are interpreted as module groups. Each module group will emit separate file. |

#### childCompilation

- Signature: (PitchCompilationContext) => void

- Hook: SyncHook

- Hook called when the compilation of child Compiler is run.

Use this hook if you need to modify the child Compiler's Compilation or if
you want to access child Compiler's Compilation's hooks yourself.

- Default: No behaviour.

| Argument | Description |
| ----------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| PitchCompilationContext | Context available in loader's pitch function on child Compiler's thisCompilation hook. See PitchCompilationContext for details. |

#### childCompiler

- Signature: (PitchCompilerContext) => void

- Hook: AsyncParallelHook

- Hook called after a child Compiler was set up in loader's pitch method.
Child Compiler is used to evaluate the modules passed to the loader, and the
resulting content will be extracted.

Use this hook if you need to modify the child Compiler before other hooks are
tapped, or if you want to access child Compiler's hooks yourself.

- Default: No behaviour.

| Argument | Description |
| ----------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| PitchCompilerContext | Context available in loader's pitch function on creation of child Compiler instance. See PitchCompilerContext for details. |

#### compiler

- Signature: (CompilerContext) => void

- Hook: SyncHook

- Hook called at the beginning of plugin's
apply
method. Use if you need to access Compiler hooks or if you need to set things
up at the beginning of the process.

- Default: No behaviour.

| Argument | Description |
| ------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------- |
| CompilerContext | Context available in Plugin's apply method. See CompilerContext for details. |

#### compilation

- Signature: (CompilationContext) => void

- Hook: SyncHook

- Hook called at the beginning of Compiler's
thisCompilation
hook. Use if you need to access Compilation hooks.

- Default: No behaviour.

| Argument | Description |
| --------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| RenderContext | Context available on Compiler's thisCompilation hook. See CompilationContext for details. |

#### dependency

- Signature: (PitchCompilationContext,
LoaderModuleContext) =>
[DependencyOptions[]](#Options)

- Hook: SyncWaterfallHook

- Process the data that was obtained from evaluating the source code of the
Module that was passed to loader's pitch method.

The data should be processed to objects that can be passed to
dependencyClass, which will be used by Webpack to create the
extracted files.

Use this hook if you need to modify the data from Module before it is passed
to the dependencyClass, or if need to split/merge the evaluated
data.

- Default:
MiniCssExtractPlugins-derived
behaviour. Exported data is interpreted as an arrray of [ID, content]
(see source file).

| Argument | Description |
| ----------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| PitchCompilationContext | Context available in loader's pitch function on child Compiler's thisCompilation hook. See PitchCompilationContext for details. |
| LoaderModuleContext | Data generated by evaluating the source code of the Module that triggered the MiniExtractPlugin's loader. See LoaderModuleContext. |
| |

| Returns | Description |
| ------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| DependencyOptions | List of options objects to be passed to the dependencyClass to create Webpack's Dependencies. |

#### extracted

- Signature: (PitchCompilationContext,
string) => string

- Hook: SyncWaterfallHook

- Modify the source string of the module from which content has been extracted
before it is passed to Webpack.

Use this hook if you need to modify the string so it can conforms to a loader
/ parser that it will be passed to next.

- Default: Inserts comment // extracted by _plugin-name_ plus HMR compat.

| Argument | Description |
| ----------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| PitchCompilationContext | Context available in loader's pitch function on child Compiler's thisCompilation hook. See PitchCompilationContext for details. |
| remainingSource | String that will be returned to Webpack as the source of the module from which data has been extracted. |
| |

| Returns | Description |
| -------- | ------------------------------------------------------------------------------------------------------- |
| string | String that will be returned to Webpack as the source of the module from which data has been extracted. |

#### initialize

- Signature: (MiniExtractPlugin, object) => void

- Hook: SyncHook

- Modify the MiniExtractPlugin instance during initialization (called from
constructor). This hook is called after other initialization logic is done.

Use this hook if you need to extend the class with custom methods /
properties, or to set default options values.

- Default: No behaviour.

| Argument | Description |
| ----------------- | ------------------------------------------------------------ |
| instance | MiniExtractPlugin instance that is being constructed. |
| instanceOptions | Options object with which the instance is being constructed. |

#### merge

- Signature: (RenderContext,
[Module[]](#options)) =>
Source

- Hook: SyncWaterfallHook

- Hook called when merging multiple Modules into a single Source that will be
emitted into a file.

Use this hook if you want to override how Modules are merged.

- Default: Join contents with newline (\n).

| Argument | Description |
| --------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| RenderContext | Context available on Compilation's renderManifest hook. See RenderContext for details. |
| Modules | List of Options.moduleClass modules (values processed by beforeMerge). |

| Returns | Description |
| ------------------------------------------------------ | ------------------------------------------------------------------------------------------------------------------------- |
| Source | Instance of Webpack's ](https://github.com/webpack/webpack-sources" class="text-primary hover:underline" target="_blank" rel="noopener noreferrer">Source>) with content from the modules. |

#### pitch

- Signature: (PitchContext) => void

- Hook: AsyncParallelHook

- Hook called at the beginning of loader's
pitch
method. Use if you need to set up the loader environment.

- Default: No behaviour.

| Argument | Description |
| ------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------- |
| PitchContext | Context available in loader's pitch function. See PitchContext for details. |

#### renderChunk

- Signature: (RenderContext,
[Module[][]](#options)) =>
RenderManifestEntry

- Hook: SyncWaterfallHook

- Hook called when Webpack is generating a chunk (non-entrypoint file) from
the given set of module groups. Each module group should yield a separate
file. The hook should return a list of
RenderManifestEntry
objects which specify the metadata of the to-be-generated file(s).

Use this hook if you want to override how the module groups are rendered and
processed for the chunk generation.

This hook is called only if the extracted Dependencies from
dependency hook were split into chunks by Webpack.

- Default:
MiniCssExtractPlugins-derived
behaviour
(see source file).

| Argument | Description |
| --------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| RenderContext | Context available on Compilation's renderManifest hook. See RenderContext for details. |
| moduleGroups | List of lists of Options.moduleClass modules (values processed by beforeRenderChunk). |

| Returns | Description |
| ----------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| RenderManifestEntry | List of Webpack's RenderManifestEntry objects that will be used to render and create output chunk files. |

#### renderMain

- Signature: (RenderContext,
[Module[][]](#options)) =>
RenderManifestEntry

- Hook: SyncWaterfallHook

- Hook called when Webpack is generating a main (entrypoint) file from
the given set of module groups. Each module group should yield a separate
file. The hook should return a list of
RenderManifestEntry
objects which specify the metadata of the to-be-generated file(s).

Use this hook if you want to override how the module groups are rendered and
processed for the entry file generation.

- Default:
MiniCssExtractPlugins-derived
behaviour
(see source file).

| Argument | Description |
| --------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| RenderContext | Context available on Compilation's renderManifest hook. See RenderContext for details. |
| moduleGroups | List of lists of Options.moduleClass modules (values processed by beforeRenderMain). |

| Returns | Description |
| ----------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| RenderManifestEntry | List of Webpack's RenderManifestEntry objects that will be used to render and create output files. |

#### source

- Signature: (PitchCompilationContext) => string

- Hook: AsyncSeriesWaterfallHook

- Get source code from a Module that was passed to loader's pitch method. Use
this hook if you need to modify the source code before it is evaluated.

- Default: No modifications done.

| Argument | Description |
| ----------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| PitchCompilationContext | Context available in loader's pitch function on child Compiler's thisCompilation hook. See PitchCompilationContext for details. |

| Returns | Description |
| ------------------ | ----------------------------------------------------------------------------------------------- |
| ModuleSourceCode | String representation of the Module's` content that was intercepted by the loader. |

$3

Hooks can be tapped to modify the extraction process at different stages.
T