And peace returned to the land! Hail neostandard!

I happened to hit upon one of the previous issues we'd come across when considering how we could get ESLint and StandardJS to work together. [Support for Eslint v9 Flat Config format](standard/eslint-config-standard#411) was one of the blockers that meant to have both ESLint and StandardJS play ball, we were stuck on ESLint v8.

I spotted that there had been some [recent activity](standard/eslint-config-standard#411 (comment)), all of which referenced an alternative called 'neostandard'.

And oh my! All my issues/dreams were answered

- Built for ESlint to avoid the need for separate IDE tooling
- Built for the latest ESLint (v9) so flat-file config is supported
- Just like we did, any style rules have been updated to use @stylistic/eslint-plugin
- A desire to work with current practices. So, banning or requiring ; is an option, along with disabling style rules for those opting to use prettier

For context, maintenance on StandardJS and related packages like eslint-config-standard has been stalled for some time. neostandard references the issue as being a [block in governance and direction of travel](standard/standard#1948). I've not been through every message, but it appears the maintainers are split between those who remained committed to StandardJS's 'one-tool one way' approach and those looking to move to where most folks are: ESLint.

Even our own @johnwatson484 [has gotten involved!](standard/standard#1948 (comment))

The thread suggests that those behind StandardJS are open to reconciling the neostandard fork with StandardJS. But that comment was made some time ago. My bet is neostandard is here to stay as the successor to StandardJS.

So, this change strips out all my hand-cranked implementations of the StandardJS rules, including those it was implementing from other plugins and replaces them with neostandard.

Lovely!

eslint.config.js

@@ -1,14 +1,27 @@
 'use strict'
 
-const stylisticPlugin = require('@stylistic/eslint-plugin-js')
-const importPlugin = require('eslint-plugin-import')
 const jsdocPlugin = require('eslint-plugin-jsdoc')
-const nPlugin = require('eslint-plugin-n')
 const eslintPluginPrettierRecommended = require('eslint-plugin-prettier/recommended')
-const promisePlugin = require('eslint-plugin-promise')
+const neostandard = require('neostandard')
 const globals = require('globals')
 
 module.exports = [
+  // Start with neostandard ESLint rules. neostandard is the successor to StandardJS (which has stalled due to a
+  // governance issue https://github.com/standard/standard/issues/1948#issuecomment-2138078249). The maintainers of
+  // neostandard have opted to lean into ESLint rather than follow the ethos of a standalone tool.
+  //
+  // So, it might be better to think of it as superseding eslint-config-standard. But unlike that package and its
+  // issues, neostandard is built for ESLint 9, so supports the new flat-file config and uses @stylistic/eslint-plugin
+  // for style rules rather than the deprecated ES Core ones.
+  //
+  // It also acknowledges current ways of working. For example, you can now enforce instead of ban semi colons using an
+  // option (the only blocker to some people using StandardJS in the past). It also acknowledges that many projects,
+  // like ours, want to apply StandardJS code rules, but leave the formatting to Prettier. Hence, you can now deactivate
+  // its style rules with the `noStyle` option.
+  //
+  // We add it first, so if anything we do conflicts with the StandardJS rules, our customisations take precedence.
+  // https://github.com/neostandard/neostandard
+  ...neostandard({ noStyle: true }),
   {
     languageOptions: {
       ecmaVersion: 'latest',
@@ -19,14 +32,11 @@ module.exports = [
       },
       sourceType: 'commonjs'
     },
-    // Ignore the folder created when jsdocs are generated
+    // Ignore the folder created when JSDocs are generated
     ignores: ['docs/**/*'],
     plugins: {
-      '@stylistic/js': stylisticPlugin,
-      import: importPlugin,
-      jsdoc: jsdocPlugin,
-      n: nPlugin,
-      promise: promisePlugin
+      // https://github.com/gajus/eslint-plugin-jsdoc
+      jsdoc: jsdocPlugin
     },
     rules: {
       // Enforce braces around the function body of arrow functions
@@ -43,172 +53,7 @@ module.exports = [
       'jsdoc/require-hyphen-before-param-description': 'warn',
       'jsdoc/require-jsdoc': ['warn', { publicOnly: true }],
       'jsdoc/require-param': ['warn', { exemptedBy: ['private'] }],
-      'jsdoc/require-returns': ['warn', { publicOnly: true }],
-      // Core ESLint StandardJS rules copied from https://github.com/standard/eslint-config-standard with Prettier
-      // conflicting ones (checked via https://github.com/prettier/eslint-config-prettier) removed
-      'no-var': 'warn',
-      'object-shorthand': ['warn', 'properties'],
-      'accessor-pairs': ['error', { setWithoutGet: true, enforceForClassMembers: true }],
-      'array-callback-return': [
-        'error',
-        {
-          allowImplicit: false,
-          checkForEach: false
-        }
-      ],
-      camelcase: [
-        'error',
-        {
-          allow: ['^UNSAFE_'],
-          properties: 'never',
-          ignoreGlobals: true
-        }
-      ],
-      'constructor-super': 'error',
-      curly: ['error', 'all'],
-      'default-case-last': 'error',
-      'dot-notation': ['error', { allowKeywords: true }],
-      eqeqeq: ['error', 'always', { null: 'ignore' }],
-      'lines-between-class-members': ['error', 'always', { exceptAfterSingleLine: true }],
-      'new-cap': ['error', { newIsCap: true, capIsNew: false, properties: true }],
-      'no-array-constructor': 'error',
-      'no-async-promise-executor': 'error',
-      'no-caller': 'error',
-      'no-case-declarations': 'error',
-      'no-class-assign': 'error',
-      'no-compare-neg-zero': 'error',
-      'no-cond-assign': 'error',
-      'no-const-assign': 'error',
-      'no-constant-condition': ['error', { checkLoops: false }],
-      'no-control-regex': 'error',
-      'no-debugger': 'error',
-      'no-delete-var': 'error',
-      'no-dupe-args': 'error',
-      'no-dupe-class-members': 'error',
-      'no-dupe-keys': 'error',
-      'no-duplicate-case': 'error',
-      'no-useless-backreference': 'error',
-      'no-empty': ['error', { allowEmptyCatch: true }],
-      'no-empty-character-class': 'error',
-      'no-empty-pattern': 'error',
-      'no-eval': 'error',
-      'no-ex-assign': 'error',
-      'no-extend-native': 'error',
-      'no-extra-bind': 'error',
-      'no-extra-boolean-cast': 'error',
-      'no-fallthrough': 'error',
-      'no-func-assign': 'error',
-      'no-global-assign': 'error',
-      'no-implied-eval': 'error',
-      'no-import-assign': 'error',
-      'no-invalid-regexp': 'error',
-      'no-irregular-whitespace': 'error',
-      'no-iterator': 'error',
-      'no-labels': ['error', { allowLoop: false, allowSwitch: false }],
-      'no-lone-blocks': 'error',
-      'no-loss-of-precision': 'error',
-      'no-misleading-character-class': 'error',
-      'no-prototype-builtins': 'error',
-      'no-useless-catch': 'error',
-      'no-multi-str': 'error',
-      'no-new': 'error',
-      'no-new-func': 'error',
-      'no-new-object': 'error',
-      'no-new-symbol': 'error',
-      'no-new-wrappers': 'error',
-      'no-obj-calls': 'error',
-      'no-octal': 'error',
-      'no-octal-escape': 'error',
-      'no-proto': 'error',
-      'no-redeclare': ['error', { builtinGlobals: false }],
-      'no-regex-spaces': 'error',
-      'no-return-assign': ['error', 'except-parens'],
-      'no-self-assign': ['error', { props: true }],
-      'no-self-compare': 'error',
-      'no-sequences': 'error',
-      'no-shadow-restricted-names': 'error',
-      'no-sparse-arrays': 'error',
-      'no-template-curly-in-string': 'error',
-      'no-this-before-super': 'error',
-      'no-throw-literal': 'error',
-      'no-undef': 'error',
-      'no-undef-init': 'error',
-      'no-unmodified-loop-condition': 'error',
-      'no-unneeded-ternary': ['error', { defaultAssignment: false }],
-      'no-unreachable': 'error',
-      'no-unreachable-loop': 'error',
-      'no-unsafe-finally': 'error',
-      'no-unsafe-negation': 'error',
-      'no-unused-expressions': [
-        'error',
-        {
-          allowShortCircuit: true,
-          allowTernary: true,
-          allowTaggedTemplates: true
-        }
-      ],
-      'no-unused-vars': [
-        'error',
-        {
-          args: 'none',
-          caughtErrors: 'none',
-          ignoreRestSiblings: true,
-          vars: 'all'
-        }
-      ],
-      'no-use-before-define': ['error', { functions: false, classes: false, variables: false }],
-      'no-useless-call': 'error',
-      'no-useless-computed-key': 'error',
-      'no-useless-constructor': 'error',
-      'no-useless-escape': 'error',
-      'no-useless-rename': 'error',
-      'no-useless-return': 'error',
-      'no-void': 'error',
-      'no-with': 'error',
-      'one-var': ['error', { initialized: 'never' }],
-      'prefer-const': ['error', { destructuring: 'all' }],
-      'prefer-promise-reject-errors': 'error',
-      'prefer-regex-literals': ['error', { disallowRedundantWrapping: true }],
-      'spaced-comment': [
-        'error',
-        'always',
-        {
-          line: { markers: ['*package', '!', '/', ',', '='] },
-          block: { balanced: true, markers: ['*package', '!', ',', ':', '::', 'flow-include'], exceptions: ['*'] }
-        }
-      ],
-      'symbol-description': 'error',
-      'unicode-bom': ['error', 'never'],
-      'use-isnan': [
-        'error',
-        {
-          enforceForSwitchCase: true,
-          enforceForIndexOf: true
-        }
-      ],
-      'valid-typeof': ['error', { requireStringLiterals: true }],
-      yoda: ['error', 'never'],
-      // Core ESLint StandardJS rules copied from https://github.com/standard/eslint-config-standard but updated because
-      // it is using the deprecated version and configured not to conflict with our prettier set up
-      '@stylistic/js/no-tabs': ['error', { allowIndentationTabs: true }],
-      '@stylistic/js/quotes': ['error', 'single', { avoidEscape: true, allowTemplateLiterals: false }],
-      // eslint-config-import StandardJS rules copied from https://github.com/standard/eslint-config-standard
-      'import/export': 'error',
-      'import/first': 'error',
-      'import/no-absolute-path': ['error', { esmodule: true, commonjs: true, amd: false }],
-      'import/no-duplicates': 'error',
-      'import/no-named-default': 'error',
-      'import/no-webpack-loader-syntax': 'error',
-      // eslint-config-n StandardJS rules copied from https://github.com/standard/eslint-config-standard
-      'n/handle-callback-err': ['error', '^(err|error)$'],
-      'n/no-callback-literal': 'error',
-      'n/no-deprecated-api': 'error',
-      'n/no-exports-assign': 'error',
-      'n/no-new-require': 'error',
-      'n/no-path-concat': 'error',
-      'n/process-exit-as-throw': 'error',
-      // eslint-config-promise StandardJS rules copied from https://github.com/standard/eslint-config-standard
-      'promise/param-names': 'error'
+      'jsdoc/require-returns': ['warn', { publicOnly: true }]
     },
     settings: {
       jsdoc: {
@@ -217,15 +62,19 @@ module.exports = [
       }
     }
   },
-  // This section works as an override to the configuration object above. It tells jsdoc to ignore any files in the
-  // `app/controllers` and `db/seeds` directories. The controllers purposefully do very little and the purpose of the
-  // seed files is obvious
+  // This section works as an override to the configuration object above. It tells the jsdoc plugin to ignore any files
+  // in the `app/controllers` and `db/seeds` directories. The controllers purposefully do very little and the purpose of
+  // the seed files is obvious
   {
     files: ['app/controllers/**/*', 'db/seeds/**/*'],
     rules: {
       'jsdoc/require-jsdoc': 'off'
     }
   },
-  // Any other config imports go at the top
+  // Adds prettier ESLint rules. It automatically sets up eslint-config-prettier, which turns off any rules declared
+  // above that conflict with prettier. That shouldn't be any, as we tell neostandard not to include any style rules
+  // and the ones we've declared we've done as per eslint-config-prettier docs on special rules. As recommended by
+  // eslint-plugin-prettier, we declare this config last
+  // https://github.com/prettier/eslint-plugin-prettier?tab=readme-ov-file#configuration-new-eslintconfigjs
   eslintPluginPrettierRecommended
 ]