.eslintrc.js

module.exports = {
  parser: '@typescript-eslint/parser', // Specifies the ESLint parser
  extends: [
    'eslint:recommended',
    'plugin:preact/recommended',
    'plugin:@typescript-eslint/recommended',
    'prettier/@typescript-eslint',
    'plugin:prettier/recommended',
    'plugin:chai-expect/recommended',
    'preact',
  ],
  settings: {
    preact: {
      version: 'detect',
    },
  },
  env: {
    browser: true,
    node: true,
    es6: true,
    jest: false,
  },
  plugins: ['@typescript-eslint', 'preact'],
  parserOptions: {
    ecmaFeatures: {
      jsx: true,
    },
    ecmaVersion: 2018, // Allows for the parsing of modern ECMAScript features
    sourceType: 'module', // Allows for the use of imports
  },
  rules: {
    'preact/prop-types': 'off', // Disable prop-types as we use TypeScript for type checking
    '@typescript-eslint/explicit-function-return-type': 'off',
    'jest/valid-expect': 'off',
    'no-unused-vars': 'off',
  },
  overrides: [
    // Override some TypeScript rules just for .js files
    {
      files: ['*.js'],
      rules: {
        '@typescript-eslint/no-var-requires': 'off', //
      },
    },
  ],
}