Remove standard in favour of eslint

Mostly because of unmaintained libraries in the Standard family and
the upcoming migration to Vite

Ref:
- standard/standardx#42
- standard/eslint-config-standard#229
- standard/standard-loader#104

.eslintignore

@@ -0,0 +1,3 @@
+/**/vendor/*.js
+/app/assets/config/**/*.js
+/config/**/*.js

.eslintrc.cjs

@@ -0,0 +1,112 @@
+module.exports = {
+  root: true,
+  extends: [
+    'plugin:import/errors',
+    'plugin:import/warnings',
+    'plugin:unicorn/recommended',
+    'xo',
+    'xo/browser'
+  ],
+  rules: {
+    'arrow-body-style': 'off',
+    'capitalized-comments': 'off',
+    'comma-dangle': [
+      'error',
+      'never'
+    ],
+    'import/extensions': [
+      'error',
+      'ignorePackages',
+      {
+        js: 'always'
+      }
+    ],
+    'import/first': 'error',
+    'import/newline-after-import': 'error',
+    'import/no-absolute-path': 'error',
+    'import/no-amd': 'error',
+    'import/no-anonymous-default-export': [
+      'error',
+      {
+        allowObject: true
+      }
+    ],
+    'import/no-cycle': [
+      'error',
+      {
+        ignoreExternal: true
+      }
+    ],
+    'import/no-duplicates': 'error',
+    'import/no-extraneous-dependencies': 'error',
+    'import/no-mutable-exports': 'error',
+    'import/no-named-as-default': 'error',
+    'import/no-named-as-default-member': 'error',
+    'import/no-named-default': 'error',
+    'import/no-self-import': 'error',
+    'import/no-unassigned-import': 'off',
+    'import/no-useless-path-segments': 'error',
+    'import/order': 'off',
+    indent: [
+      'error',
+      2,
+      {
+        MemberExpression: 'off',
+        SwitchCase: 1
+      }
+    ],
+    'max-params': [
+      'warn',
+      5
+    ],
+    'multiline-ternary': [
+      'error',
+      'always-multiline'
+    ],
+    'new-cap': [
+      'error',
+      {
+        properties: false
+      }
+    ],
+    'no-console': 'error',
+    'no-negated-condition': 'off',
+    'object-curly-spacing': [
+      'error',
+      'always'
+    ],
+    'operator-linebreak': [
+      'error',
+      'after'
+    ],
+    'prefer-template': 'error',
+    semi: [
+      'error',
+      'never'
+    ],
+    strict: 'error',
+    'unicorn/explicit-length-check': 'off',
+    'unicorn/filename-case': 'off',
+    'unicorn/no-array-callback-reference': 'off',
+    'unicorn/no-array-method-this-argument': 'off',
+    'unicorn/no-null': 'off',
+    'unicorn/no-typeof-undefined': 'off',
+    'unicorn/no-unused-properties': 'error',
+    'unicorn/numeric-separators-style': 'off',
+    'unicorn/prefer-array-flat': 'off',
+    'unicorn/prefer-at': 'off',
+    'unicorn/prefer-dom-node-dataset': 'off',
+    'unicorn/prefer-module': 'off',
+    'unicorn/prefer-query-selector': 'off',
+    'unicorn/prefer-spread': 'off',
+    'unicorn/prefer-string-replace-all': 'off',
+    'unicorn/prevent-abbreviations': 'off'
+  },
+  settings: {
+    'import/resolver': {
+      node: {
+        paths: ['app/javascript']
+      }
+    }
+  }
+}

config/webpack/development.js

@@ -1,22 +1,14 @@
+const ESLintPlugin = require('eslint-webpack-plugin')
 const StyleLintPlugin = require('stylelint-webpack-plugin')
 
 module.exports = {
   envSpecificConfig: {
-    module: {
-      rules: [
-        {
-          test: /\.js$/,
-          exclude: /vendor\/.+\.js$/,
-          loader: 'standard-loader',
-          options: {
-            globals: [
-              '$'
-            ]
-          }
-        }
-      ]
-    },
     plugins: [
+      new ESLintPlugin({
+        failOnError: false,
+        files: 'app/javascript/**/*.js',
+        exclude: 'app/javascript/src/vendor/**/*.js'
+      }),
       new StyleLintPlugin({
         failOnError: false,
         files: 'app/javascript/**/*.(s(c|a)ss|css)'

lib/tasks/yarn_linters.rake

@@ -24,12 +24,12 @@ namespace :yarn do
     Rake::Task['yarn:run'].execute(command: "stylelint #{Dir.glob('app/**/*.scss').join(' ')}")
   end
 
-  desc 'Run `bin/yarn standard`'
-  task :standard do
-    Rake::Task['yarn:run'].execute(command: 'standard')
+  desc 'Run `bin/yarn eslint`'
+  task :eslint do
+    Rake::Task['yarn:run'].execute(command: 'eslint app/**/*.js')
   end
   # rubocop:enable Rails/RakeEnvironment
 end
 
 task(:lint).sources.push 'yarn:stylelint'
-task(:lint).sources.push 'yarn:standard'
+task(:lint).sources.push 'yarn:eslint'

package.json

@@ -47,25 +47,18 @@
     "@babel/eslint-parser": "^7.23.3",
     "@types/express": "^4.17.21",
     "@webpack-cli/serve": "^2.0.4",
-    "eslint": "^8.56.0",
-    "standard": "^16.0.3",
-    "standard-loader": "^7.0.0",
+    "eslint": ">=8.27.0",
+    "eslint-config-xo": "^0.43.1",
+    "eslint-plugin-import": "^2.29.1",
+    "eslint-plugin-unicorn": "^50.0.1",
+    "eslint-webpack-plugin": "^4.0.1",
     "stylelint": "^15.11.0",
     "stylelint-config-twbs-bootstrap": "^12.0.0",
     "stylelint-order": "^6.0.4",
     "stylelint-scss": "^5.3.2",
     "stylelint-webpack-plugin": "^4.1.1",
     "webpack-dev-server": "^4.15.1"
   },
-  "standard": {
-    "parser": "@babel/eslint-parser",
-    "ignore": [
-      "/*.js",
-      "app/assets/javascripts",
-      "app/javascript/src/vendor",
-      "/config"
-    ]
-  },
   "babel": {
     "presets": [
       "./node_modules/shakapacker/package/babel/preset.js"