Install

$ npm i html-jsx

Usage

Because of the way TypeScript and JSX work, we have to insert this piece of code where the createElement (or h) factory lives in order for the types to be picked up correctly by the compiler:

import type * as jsx from 'html-jsx'

// this declaration allows us to augment JSX interfaces
declare module 'html-jsx' {
  // eslint-disable-next-line @typescript-eslint/no-unused-vars
  interface DOMAttributes<T> extends JSX.IntrinsicAttributes {
    // here we could add attributes specific only to DOM elements (HTML+SVG)
  }
}

// this introduces our JSX definitions into the global scope
declare global {
  namespace JSX {
    /** The type returned by our `createElement` factory. */
    type Element = string

    interface IntrinsicElements extends jsx.IntrinsicElements {
      /** This allows for any tag to be used. */
      [k: string]: unknown
    }

    // here we can add attributes for all the elements
    interface IntrinsicAttributes {
      /** List index key - each item's `key` must be unique. */
      key?: string | number
    }

    /**
     * These are exported to the global JSX namespace to allow
     * declaring custom elements types.
     * @see `playground/app.tsx`
     */
    interface HTMLAttributes<T> extends jsx.HTMLAttributes<T> {}
    interface SVGAttributes<T> extends jsx.SVGAttributes<T> {}
    interface DOMAttributes<T> extends jsx.DOMAttributes<T> {}
  }
}

After this, html JSX tags in our application(or library) plus anything else that depends on it, should be properly picking up the types, with intellisense, documentation and lint working.

See playground for more usage details.

Extras

An eslint configuration based on eslint-plugin-react that only enables JSX rules that would possibly cause problems is available here. No stylistic rules are applied (use Prettier for this). It also sets up the JSX pragma to h and the fragment to Fragment which is probably what you need. All these can be configured again, or you can use the react plugin directly. This is only for convenience for my own projects basically but distributing it to save someone's time potentially.

To use it, just install it and add to your eslint config:

$ npm i eslint-config-html-jsx

eslintrc.js:

...
  extends: ['html-jsx'],
...

Credits

• markuplint for the html-spec data which are used to generate most of the HTML types and documentation.

• ko-jsx which this was based on, which was itself based on Surplus and Inferno which were themselves based off React's.

• CSSType for the rules that are used in the style attributes.

• Of course, Mozilla MDN which all of the previous are based on.

• Many thanks to everyone who contributed.

Contribute

Fork or edit and submit a PR.

All contributions are welcome!

License

MIT © 2021 stagas