# Type alias AddOnFeatures

AddOnFeatures: {
eslint?: boolean;
flow?: boolean;
jest?: boolean;
karma?: boolean;
mocha?: boolean;
reactLib?: "react" | "preact" | "inferno";
sass?: boolean;
typescript?: boolean;
}

Optional features to support

#### Type declaration

- ##### `Optional` eslint?: boolean

  Enable xarc's built-in eslint checks

  - This is enabled if you add `@xarc/opt-eslint` to your devDependencies

- ##### `Optional` flow?: boolean

  Enable flow.js support? Default: `false`

- ##### `Optional` jest?: boolean

  Enable support for running test with jest

  - This is enabled if you add `@xarc/opt-jest` to your devDependencies

- ##### `Optional` karma?: boolean

  Enable support for running function tests with Karma

  - Default: `false`
  - This is enabled if you add `@xarc/opt-karma` to your devDependencies

- ##### `Optional` mocha?: boolean

  Enable support for running tests with mocha

  - This is enabled if you add `@xarc/opt-mocha` to your devDependencies

- ##### `Optional` reactLib?: "react" | "preact" | "inferno"

  Select an implementation of the React UI framework Default: `react`

- ##### `Optional` sass?: boolean

  Enable support for sass styling

  - This is enabled if you add `@xarc/opt-sass` to your devDependencies

- ##### `Optional` typescript?: boolean

  Enable support for using TypeScript

- Defined in packages/xarc-app-dev/src/config/opt2/add-on-features.ts:4