html-rewriter.d.ts

declare namespace HTMLRewriterTypes {
  interface HTMLRewriterElementContentHandlers {
    element?(element: Element): void | Promise<void>;
    comments?(comment: Comment): void | Promise<void>;
    text?(text: Text): void | Promise<void>;
  }

  interface HTMLRewriterDocumentContentHandlers {
    doctype?(doctype: Doctype): void | Promise<void>;
    comments?(comment: Comment): void | Promise<void>;
    text?(text: Text): void | Promise<void>;
    end?(end: DocumentEnd): void | Promise<void>;
  }

  interface Text {
    readonly text: string;
    readonly lastInTextNode: boolean;
    readonly removed: boolean;
    before(content: Content, options?: ContentOptions): Text;
    after(content: Content, options?: ContentOptions): Text;
    replace(content: Content, options?: ContentOptions): Text;
    remove(): Text;
  }

  interface Doctype {
    readonly name: string | null;
    readonly publicId: string | null;
    readonly systemId: string | null;
  }

  interface DocumentEnd {
    append(content: Content, options?: ContentOptions): DocumentEnd;
  }

  interface ContentOptions {
    html?: boolean;
  }
  type Content = string;

  interface Comment {
    text: string;
    readonly removed: boolean;
    before(content: Content, options?: ContentOptions): Comment;
    after(content: Content, options?: ContentOptions): Comment;
    replace(content: Content, options?: ContentOptions): Comment;
    remove(): Comment;
  }

  interface Element {
    tagName: string;
    readonly attributes: IterableIterator<string[]>;
    readonly removed: boolean;
    readonly namespaceURI: string;
    getAttribute(name: string): string | null;
    hasAttribute(name: string): boolean;
    setAttribute(name: string, value: string): Element;
    removeAttribute(name: string): Element;
    before(content: Content, options?: ContentOptions): Element;
    after(content: Content, options?: ContentOptions): Element;
    prepend(content: Content, options?: ContentOptions): Element;
    append(content: Content, options?: ContentOptions): Element;
    replace(content: Content, options?: ContentOptions): Element;
    remove(): Element;
    removeAndKeepContent(): Element;
    setInnerContent(content: Content, options?: ContentOptions): Element;
    onEndTag(handler: (tag: EndTag) => void | Promise<void>): void;
  }

  interface EndTag {
    name: string;
    before(content: Content, options?: ContentOptions): EndTag;
    after(content: Content, options?: ContentOptions): EndTag;
    remove(): EndTag;
  }
}

/**
 * [HTMLRewriter](https://developers.cloudflare.com/workers/runtime-apis/html-rewriter?bun) is a fast API for transforming HTML.
 *
 * Bun leverages a native implementation powered by [lol-html](https://github.com/cloudflare/lol-html).
 *
 * HTMLRewriter can be used to transform HTML in a variety of ways, including:
 * * Rewriting URLs
 * * Adding meta tags
 * * Removing elements
 * * Adding elements to the head
 *
 * @example
 * ```ts
 * const rewriter = new HTMLRewriter().on('a[href]', {
 *   element(element: Element) {
 *     // Rewrite all the URLs to this youtube video
 *     element.setAttribute('href', 'https://www.youtube.com/watch?v=dQw4w9WgXcQ');
 *   }
 * });
 * rewriter.transform(await fetch("https://remix.run"));
 * ```
 */
declare class HTMLRewriter {
  constructor();
  on(
    selector: string,
    handlers: HTMLRewriterTypes.HTMLRewriterElementContentHandlers
  ): HTMLRewriter;
  onDocument(
    handlers: HTMLRewriterTypes.HTMLRewriterDocumentContentHandlers
  ): HTMLRewriter;
  /**
   * @param input - The HTML to transform
   * @returns A new {@link Response} with the transformed HTML
   */
  transform(input: Response): Response;
}