@ionic/eslint-config

Shared ESLint config used in Ionic and Capacitor projects.

This is meant to be used alongside Prettier (with @ionic/prettier-config).

v0.5.0 requires ESLint 10 and a flat config file. Staying on ESLint 8 or 9? Keep using @ionic/eslint-config@0.4.0.

Usage

1. Install eslint and the config:

   npm install -D eslint @ionic/eslint-config
   

2. Create an eslint.config.cjs in your project root:

   const ionic = require('@ionic/eslint-config/recommended');
   
   module.exports = [
     { ignores: ['dist/**', 'build/**'] },
     ...ionic,
   ];

   From an ESM config (eslint.config.mjs), import '@ionic/eslint-config/recommended.js'.

📝 You can also use the base rule set: @ionic/eslint-config

Both rule sets apply only to TypeScript files (.ts, .tsx, .mts, .cts). To lint JavaScript too, add your own config block.

With Prettier and @ionic/prettier-config

1. Set up Prettier and @ionic/prettier-config.

2. When using with Prettier and @ionic/prettier-config, ESLint should run first. Set up your scripts in package.json like this:

     "scripts": {
       "lint": "npm run eslint && npm run prettier -- --check",
       "fmt": "npm run eslint -- --fix && npm run prettier -- --write",
       "prettier": "prettier \"**/*.ts\"",
       "eslint": "eslint"
     }

   • npm run lint: for checking if ESLint and Prettier complain
   • npm run fmt: attempt to autofix lint issues and autoformat code

   📝 Not every rule in this configuration is autofixable, so npm run fmt may continue failing until lint issues are addressed manually.

Migrating from 0.4 or earlier

1. Delete the eslintConfig block from package.json (or any .eslintrc file).
2. Add an eslint.config.cjs as shown above.
3. Move .eslintignore entries into ignores, then delete the file.
4. Drop --ext ts from lint scripts; flat config ignores the flag.

New reports to expect:

• no-unused-vars now flags unused catch (e) bindings. Use catch {} instead.
• no-var-requires was renamed to no-require-imports. Update any disable comments.
• import/* rules are now import-x/*. Update any disable comments.
• prefer-optional-chain is no longer in recommended; it now requires typed linting. Re-enable it in your own config if you use typed linting.

With Husky

1. Install husky:

   npm install -D husky
   

2. Add the following to package.json:

     "husky": {
       "hooks": {
         "pre-commit": "npm run lint"
       }
     },