Upgrade to Webpacker 6.0.

config/webpack/base.js

@@ -0,0 +1,25 @@
+const { webpackConfig, merge } = require('@rails/webpacker')
+
+module.exports = merge(webpackConfig, {
+  output: {
+    library: "Danbooru",
+  },
+  resolve: {
+    alias: {
+      "jquery": "jquery/src/jquery.js",
+      "react": "preact/compat",
+      "react-dom": "preact/compat",
+    }
+  },
+  module: {
+    rules: [{
+      test: /.erb$/,
+      enforce: "pre",
+      exclude: /node_modules/,
+      loader: "rails-erb-loader",
+      options: {
+        runner: "bin/rails runner"
+      }
+    }]
+  },
+});

config/webpack/development.js

@@ -1,8 +1,15 @@
 process.env.NODE_ENV = process.env.NODE_ENV || 'development'
 
-const environment = require('./environment')
-const eslint = require('./loaders/eslint')
+const { merge } = require('@rails/webpacker')
+const webpackConfig = require('./base');
+const ESLintPlugin = require('eslint-webpack-plugin');
 
-environment.loaders.append('eslint', eslint);
-
-module.exports = environment.toWebpackConfig()
+module.exports = merge(webpackConfig, {
+  plugins: [
+    new ESLintPlugin({
+      cache: true,
+      threads: true,
+      emitWarning: true
+    })
+  ]
+});

config/webpack/environment.js

@@ -1,15 +0,0 @@
-const { environment } = require('@rails/webpacker')
-const erb =  require('./loaders/erb')
-const webpack = require('webpack');
-
-environment.loaders.append('erb', erb);
-
-environment.config.output.library = ["Danbooru"];
-
-environment.config.set("resolve.alias", {
-  "jquery": "jquery/src/jquery.js",
-  "react": "preact/compat",
-  "react-dom": "preact/compat",
-});
-
-module.exports = environment

config/webpack/loaders/erb.js

@@ -1,11 +0,0 @@
-module.exports = {
-  test: /\.erb$/,
-  enforce: 'pre',
-  exclude: /node_modules/,
-  use: [{
-    loader: 'rails-erb-loader',
-    options: {
-      runner: (/^win/.test(process.platform) ? 'ruby ' : '') + 'bin/rails runner'
-    }
-  }]
-}

config/webpack/loaders/eslint.js

@@ -1,10 +0,0 @@
-module.exports = {
-  enforce: 'pre',
-  test: /\.(js)$/i,
-  exclude: /node_modules|vendor/,
-  loader: 'eslint-loader',
-  options: {
-    cache: true,
-    emitWarning: true,
-  }
-}

config/webpack/production.js

@@ -1,5 +1,5 @@
 process.env.NODE_ENV = process.env.NODE_ENV || 'production'
 
-const environment = require('./environment')
+const webpackConfig = require('./base')
 
-module.exports = environment.toWebpackConfig()
+module.exports = webpackConfig

config/webpack/test.js

@@ -1,5 +1,5 @@
 process.env.NODE_ENV = process.env.NODE_ENV || 'development'
 
-const environment = require('./environment')
+const webpackConfig = require('./base')
 
-module.exports = environment.toWebpackConfig()
+module.exports = webpackConfig