Use same hook for both webpack 4 and 5

README.md

@@ -165,6 +165,15 @@ Default: `false`
 
 If `true`, the keys specified in the `entry` property will be used as keys in the manifest. No file extension will be added (unless specified as part of an `entry` property key).
 
+### `useLegacyEmit`
+
+Type: `Boolean`<br>
+Default: `false`
+
+If `true`, the manifest will be written on the deprecated webpack `emit` hook to be compatible with not yet updated webpack plugins.
+
+A lot of webpack plugins are not yet updated to match the new webpack 5 API. This is a problem when other plugins use the deprecated `emit` hook. The manifest will be written before these other plugins and thus files are missing on the manifest.
+
 ### `writeToFileEmit`
 
 Type: `Boolean`<br>

lib/index.js

@@ -23,6 +23,7 @@ const defaults = {
   sort: null,
   transformExtensions: /^(gz|map)$/i,
   useEntryKeys: false,
+  useLegacyEmit: false,
   writeToFileEmit: false
 };
 
@@ -57,7 +58,7 @@ class WebpackManifestPlugin {
       hook.tap(hookOptions, normalModuleLoader);
     });
 
-    if (webpack.version.startsWith('4')) {
+    if (webpack.version.startsWith('4') || this.options.useLegacyEmit === true) {
       compiler.hooks.emit.tap(hookOptions, emit);
     } else {
       compiler.hooks.thisCompilation.tap(hookOptions, (compilation) => {

package.json

@@ -42,6 +42,7 @@
   "devDependencies": {
     "@ava/babel": "^1.0.1",
     "@svgr/webpack": "^5.4.0",
+    "@wordpress/dependency-extraction-webpack-plugin": "^3.1.0",
     "ava": "^3.13.0",
     "codecov": "^3.1.0",
     "copy-webpack-plugin": "^6.2.1",

test/unit/options.js

@@ -2,6 +2,7 @@ const { join } = require('path');
 
 const test = require('ava');
 const CopyPlugin = require('copy-webpack-plugin');
+const DependencyExtractionWebpackPlugin = require('@wordpress/dependency-extraction-webpack-plugin');
 const del = require('del');
 
 const { compile } = require('../helpers/unit');
@@ -119,3 +120,24 @@ test('useEntryKeys, exclude sourcemap', async (t) => {
 
   t.snapshot(manifest);
 });
+
+test('useLegacyEmit', async (t) => {
+  const config = {
+    context: __dirname,
+    entry: {
+      main: '../fixtures/file.js'
+    },
+    output: {
+      filename: '[name].js',
+      path: join(outputPath, 'useLegacyEmit')
+    },
+    plugins: [
+      new DependencyExtractionWebpackPlugin({
+        outputFormat: 'json'
+      })
+    ]
+  };
+  const { manifest } = await compile(config, t, { useLegacyEmit: true });
+
+  t.snapshot(manifest);
+});

test/unit/snapshots/options.js.md

@@ -56,3 +56,12 @@ Generated by [AVA](https://avajs.dev).
       main: 'main.js',
       'main.js.map': 'main.js.map',
     }
+
+## useLegacyEmit
+
+> Snapshot 1
+
+    {
+      'main.js': 'main.js',
+      'main.json': 'main.asset.json',
+    }