fix: compatibility with webpack v5

src/index.js

@@ -1,7 +1,6 @@
 /* eslint-disable class-methods-use-this */
 
 import webpack from 'webpack';
-
 import { validate } from 'schema-utils';
 
 import CssModuleFactory from './CssModuleFactory';
@@ -482,6 +481,11 @@ class MiniCssExtractPlugin {
  }
  );
  } else {
+ // TODO remove after drop webpack v4
+ const { RuntimeGlobals, runtime } = compiler.webpack
+ ? compiler.webpack
+ : // eslint-disable-next-line global-require
+ require('webpack');
  const enabledChunks = new WeakSet();
  const handler = (chunk, set) => {
  if (enabledChunks.has(chunk)) {
@@ -494,17 +498,17 @@ class MiniCssExtractPlugin {
  typeof this.options.chunkFilename === 'string' &&
  /\[(full)?hash(:\d+)?\]/.test(this.options.chunkFilename)
  ) {
- set.add(webpack.RuntimeGlobals.getFullHash);
+ set.add(RuntimeGlobals.getFullHash);
  }
 
- set.add(webpack.RuntimeGlobals.publicPath);
+ set.add(RuntimeGlobals.publicPath);
 
  compilation.addRuntimeModule(
  chunk,
- new webpack.runtime.GetChunkFilenameRuntimeModule(
+ new runtime.GetChunkFilenameRuntimeModule(
  MODULE_TYPE,
  'mini-css',
- `${webpack.RuntimeGlobals.require}.miniCssF`,
+ `${RuntimeGlobals.require}.miniCssF`,
  (referencedChunk) => {
  if (!referencedChunk.contentHash[MODULE_TYPE]) {
  return false;
@@ -528,10 +532,10 @@ class MiniCssExtractPlugin {
  };
 
  compilation.hooks.runtimeRequirementInTree
- .for(webpack.RuntimeGlobals.ensureChunkHandlers)
+ .for(RuntimeGlobals.ensureChunkHandlers)
  .tap(pluginName, handler);
  compilation.hooks.runtimeRequirementInTree
- .for(webpack.RuntimeGlobals.hmrDownloadUpdateHandlers)
+ .for(RuntimeGlobals.hmrDownloadUpdateHandlers)
  .tap(pluginName, handler);
  }
  });