ESLint

.eslintrc.js

@@ -1,11 +1,26 @@
+// TODO [eslint@>9.5]: Use `.ts` extension to get more type checking for this file.
+// TODO [engine:node@>=18]: Upgrade `tseslint`.
+// TODO [engine:node@>=18]: Use `eslint-define-config` to get type checking for this file.
+// TODO [engine:node@>=18]: Use `eslint-plugin-jsdoc` to get JSDoc linting.
+
 module.exports = {
   root: true,
-  extends: ['xo', 'turbo', 'prettier', 'plugin:@typescript-eslint/recommended'],
-  plugins: ['node', 'unicorn', '@typescript-eslint'],
+  extends: [
+    'xo', // Should we also use eslint-config-xo-typescript?
+    'turbo',
+    'plugin:n/recommended',
+    'plugin:security/recommended-legacy',
+    'plugin:@eslint-community/eslint-comments/recommended',
+    'plugin:promise/recommended',
+    'plugin:unicorn/recommended',
+    'plugin:@typescript-eslint/recommended-type-checked',
+    'plugin:@typescript-eslint/stylistic-type-checked',
+    'prettier'
+  ],
+  plugins: ['n', 'security', 'promise', 'unicorn', '@typescript-eslint'],
   parser: '@typescript-eslint/parser',
   parserOptions: {
-    project: true,
-    tsconfigRootDir: __dirname
+    EXPERIMENTAL_useProjectService: true
   },
   env: {
     node: true
@@ -16,37 +31,90 @@ module.exports = {
     'test/run-snapshots',
     'test/snapshots',
     'test/temporary',
-    'vendor/node-elm-compiler.js',
-    'vendor/exit.js',
+    'vendor/',
     '.eslintrc.js',
     'new-package/elm-review-package-tests/check-previews-compile.js'
   ],
   rules: {
+    // Style disagreements with XO.
     complexity: 'off',
     'import/extensions': 'off',
     indent: 'off',
     'comma-dangle': 'off',
     curly: 'off',
     quotes: 'off',
     'arrow-body-style': 'off',
-    'prettier/prettier': 'off',
     'object-shorthand': 'off',
     'operator-linebreak': 'off',
     'max-params': 'off',
     'arrow-parens': 'off',
     'no-warning-comments': 'off',
-    'prefer-const': 'off',
+    'promise/no-nesting': 'warn',
+    'promise/no-return-in-finally': 'error',
+    'promise/valid-params': 'error',
+    'promise/prefer-await-to-callbacks': 'warn',
     'promise/prefer-await-to-then': 'off',
-    'unicorn/no-fn-reference-in-iterator': 'off',
-    'unicorn/no-reduce': 'off',
+    'no-return-await': 'off',
+    '@typescript-eslint/return-await': ['error', 'always'],
+    'unicorn/no-array-callback-reference': 'off',
+    'unicorn/no-array-reduce': 'off',
     'unicorn/prefer-module': 'off',
-    'unicorn/prefer-node-protocol': 'off',
+    'unicorn/prefer-node-protocol': 'error',
+    'unicorn/expiring-todo-comments': 'warn',
     '@typescript-eslint/no-var-requires': 'off',
     '@typescript-eslint/no-empty-function': 'off',
     '@typescript-eslint/no-unused-vars': ['error', {argsIgnorePattern: '^_'}],
     '@typescript-eslint/switch-exhaustiveness-check': 'error',
-    'default-case': 'off'
+    '@typescript-eslint/consistent-type-definitions': ['error', 'type'],
+    'default-case': 'off',
+    'n/shebang': 'off', // TODO [eslint-plugin-n@>=17]: Turn on 'n/hashbang'. For now, `shebang` is buggy.
+    '@eslint-community/eslint-comments/require-description': 'error',
+    strict: ['error', 'global'],
+    'unicorn/import-style': [
+      'error',
+      {
+        styles: {
+          chalk: {
+            named: true
+          }
+        }
+      }
+    ],
+    'unicorn/no-null': 'off',
+    'unicorn/prevent-abbreviations': 'off',
+
+    // TODO: Once there are no more `any`s, start enforcing these rules.
+    '@typescript-eslint/no-unsafe-assignment': 'off',
+    '@typescript-eslint/no-unsafe-argument': 'off',
+    '@typescript-eslint/no-unsafe-member-access': 'off',
+    '@typescript-eslint/no-unsafe-call': 'off',
+    '@typescript-eslint/no-unsafe-return': 'off',
+
+    // TODO: Enable stricter promise rules.
+    '@typescript-eslint/no-misused-promises': 'off',
+    '@typescript-eslint/no-floating-promises': 'off',
+    'promise/catch-or-return': 'off',
+    'promise/always-return': 'off',
+
+    // TODO: Security issues that should eventually get fixed.
+    'security/detect-object-injection': 'off',
+    'security/detect-non-literal-fs-filename': 'off',
+    'security/detect-non-literal-require': 'off',
+    'security/detect-unsafe-regex': 'off', // TODO: Add `eslint-plugin-regexp` and fix these issues.
+
+    // TODO: Enable rules that require newer versions of Node.js when we bump the minimum version.
+    'unicorn/prefer-string-replace-all': 'off', // TODO [engine:node@>=15]: Enable this rule.
+    'unicorn/prefer-at': 'off' // TODO [engine:node@>=16.6]: Enable this rule.
   },
+  overrides: [
+    {
+      files: ['./new-package/**/*.js'],
+      rules: {
+        'n/no-process-exit': 'off',
+        '@typescript-eslint/unbound-method': 'off' // TODO: Fix this warning. @lishaduck just got confused.
+      }
+    }
+  ],
   globals: {
     test: 'readonly',
     expect: 'readonly'

.prettierignore

@@ -8,5 +8,6 @@
 **/suppressed
 test/**/*.json
 test/temporary/
+test/run-snapshots/
 vendor/exit.js
 .turbo

jest.config.js

@@ -195,5 +195,5 @@ module.exports = {
   // Whether to use watchman for file crawling
   // watchman: true,
 
-  testTimeout: 30000
+  testTimeout: 30_000
 };

lib/anonymize.js

@@ -4,7 +4,7 @@ so that the CLI tests (in the `test/` folder) have the same output on different
 machines, and also the same output when only the CLI version changes.
 */
 
-const path = require('path');
+const path = require('node:path');
 
 /**
  * @import {Options} from "./types/options"

lib/app-wrapper.js

@@ -1,8 +1,8 @@
-const path = require('path');
+const path = require('node:path');
 const ElmCommunication = require('./elm-communication');
 const loadCompiledElmApp = require('./load-compiled-app');
 
-const {Worker} = require('worker_threads');
+const {Worker} = require('node:worker_threads');
 
 module.exports = {
   init: (options, elmModulePath, flags) => init(options, elmModulePath, flags),
@@ -49,7 +49,7 @@ function initWithWorker(elmModulePath, flags) {
 
   worker.on('message', ([port, data]) => {
     if (listeners[port]) {
-      listeners[port].forEach((fn) => fn(data));
+      for (const fn of listeners[port]) fn(data);
     }
   });
 
@@ -67,12 +67,14 @@ function send(port) {
 }
 
 function subscribe(port) {
+  // eslint-disable-next-line promise/prefer-await-to-callbacks -- Callbacks are still needed here.
   return (callback) => {
     listeners[port].push(callback);
   };
 }
 
 function unsubscribe(port) {
+  // eslint-disable-next-line promise/prefer-await-to-callbacks -- Callbacks are still needed here.
   return (callback) => {
     listeners[port] = listeners[port].filter((fn) => fn === callback);
   };

lib/autofix.js

@@ -1,5 +1,5 @@
-const fs = require('fs');
-const path = require('path');
+const fs = require('node:fs');
+const path = require('node:path');
 const chalk = require('chalk');
 const prompts = require('prompts');
 const spawn = require('cross-spawn');
@@ -78,16 +78,7 @@ function askConfirmationToFixWithOptions(options, app, elmVersion) {
       return;
     }
 
-    const accepted =
-      options.fixAllWithoutPrompt ||
-      (
-        await prompts({
-          type: 'confirm',
-          name: 'accepted',
-          message,
-          initial: true
-        })
-      ).accepted;
+    const accepted = options.fixAllWithoutPrompt || (await confirmFix(message));
 
     if (accepted === undefined) {
       // User interrupted the process using Ctrl-C
@@ -152,6 +143,21 @@ function askConfirmationToFixWithOptions(options, app, elmVersion) {
   };
 }
 
+/**
+ * @param {string} message
+ * @returns {Promise<boolean>}
+ */
+async function confirmFix(message) {
+  const prompt = await prompts({
+    type: 'confirm',
+    name: 'accepted',
+    message,
+    initial: true
+  });
+
+  return prompt.accepted;
+}
+
 function checkIfAFixConfirmationIsStillExpected(app) {
   return promisifyPort({
     subscribeTo: app.ports.fixConfirmationStatus,
@@ -170,7 +176,7 @@ function checkIfAFixConfirmationIsStillExpected(app) {
  */
 function formatFileContent(options, file, filePath) {
   const hasElmFormatPathFlag = Boolean(options.elmFormatPath);
-  const elmFormatPath = options.elmFormatPath || 'elm-format';
+  const elmFormatPath = options.elmFormatPath ?? 'elm-format';
 
   const result = spawn.sync(
     elmFormatPath,
@@ -188,22 +194,18 @@ function formatFileContent(options, file, filePath) {
       if (hasElmFormatPathFlag) {
         throw new ErrorMessage.CustomError(
           'ELM-FORMAT NOT FOUND',
-          // prettier-ignore
-          `I could not find the executable for ${chalk.magentaBright('elm-format')} at the location you specified:
 
-  ${options.elmFormatPath}`,
-          options.elmJsonPath
-        );
-      } else {
-        throw new ErrorMessage.CustomError(
-          'ELM-FORMAT NOT FOUND',
           // prettier-ignore
-          `I could not find the executable for ${chalk.magentaBright('elm-format')}.
+          hasElmFormatPathFlag
+            ? `I could not find the executable for ${chalk.magentaBright('elm-format')} at the location you specified:
+
+  ${options.elmFormatPath}`
+            : `I could not find the executable for ${chalk.magentaBright('elm-format')}.
 
 A few options:
-- Install it globally
-- Add it to your project through \`npm\`
-- Specify the path using ${chalk.cyan('--elm-format-path <path-to-elm-format>')}`,
+- Install it globally.
+- Add it to your project through \`npm\`.
+- Specify the path using ${chalk.cyan('--elm-format-path <path-to-elm-format>')}.`,
           options.elmJsonPath
         );
       }