CustomElement inheritance in TypeScript (before it's fixed)

customelement.ts

export declare class BaseCustomHTMLElement implements HTMLElement {
    // Custom element specific
    // http://www.html5rocks.com/en/tutorials/webcomponents/customelements/
    createdCallback(): void; // an instance of the element is created
    attachedCallback(): void; // an instance was inserted into the document
    detachedCallback(): void; // an instance was removed from the document
    attributeChangedCallback(attrName: string, oldVal: any, newVal: any): void; // an attribute was added, removed, or updated
        
    // Copy & Pasted all from HTMLElement interface
    // interface HTMLElement extends Element, ElementCSSInlineStyle, MSEventAttachmentTarget, MSNodeExtensions
    onmouseleave: (ev: MouseEvent) => any;
    onbeforecut: (ev: DragEvent) => any;
    onkeydown: (ev: KeyboardEvent) => any;
    onmove: (ev: MSEventObj) => any;
    onkeyup: (ev: KeyboardEvent) => any;
    onreset: (ev: Event) => any;
    onhelp: (ev: Event) => any;
    ondragleave: (ev: DragEvent) => any;
    className: string;
    onfocusin: (ev: FocusEvent) => any;
    onseeked: (ev: Event) => any;
    recordNumber: any;
    title: string;
    parentTextEdit: Element;
    outerHTML: string;
    ondurationchange: (ev: Event) => any;
    offsetHeight: number;
    all: HTMLCollection;
    onblur: (ev: FocusEvent) => any;
    dir: string;
    onemptied: (ev: Event) => any;
    onseeking: (ev: Event) => any;
    oncanplay: (ev: Event) => any;
    ondeactivate: (ev: UIEvent) => any;
    ondatasetchanged: (ev: MSEventObj) => any;
    onrowsdelete: (ev: MSEventObj) => any;
    sourceIndex: number;
    onloadstart: (ev: Event) => any;
    onlosecapture: (ev: MSEventObj) => any;
    ondragenter: (ev: DragEvent) => any;
    oncontrolselect: (ev: MSEventObj) => any;
    onsubmit: (ev: Event) => any;
    behaviorUrns: MSBehaviorUrnsCollection;
    scopeName: string;
    onchange: (ev: Event) => any;
    id: string;
    onlayoutcomplete: (ev: MSEventObj) => any;
    uniqueID: string;
    onbeforeactivate: (ev: UIEvent) => any;
    oncanplaythrough: (ev: Event) => any;
    onbeforeupdate: (ev: MSEventObj) => any;
    onfilterchange: (ev: MSEventObj) => any;
    offsetParent: Element;
    ondatasetcomplete: (ev: MSEventObj) => any;
    onsuspend: (ev: Event) => any;
    readyState: any;
    onmouseenter: (ev: MouseEvent) => any;
    innerText: string;
    onerrorupdate: (ev: MSEventObj) => any;
    onmouseout: (ev: MouseEvent) => any;
    parentElement: HTMLElement;
    onmousewheel: (ev: MouseWheelEvent) => any;
    onvolumechange: (ev: Event) => any;
    oncellchange: (ev: MSEventObj) => any;
    onrowexit: (ev: MSEventObj) => any;
    onrowsinserted: (ev: MSEventObj) => any;
    onpropertychange: (ev: MSEventObj) => any;
    filters: Object;
    children: HTMLCollection;
    ondragend: (ev: DragEvent) => any;
    onbeforepaste: (ev: DragEvent) => any;
    ondragover: (ev: DragEvent) => any;
    offsetTop: number;
    onmouseup: (ev: MouseEvent) => any;
    ondragstart: (ev: DragEvent) => any;
    onbeforecopy: (ev: DragEvent) => any;
    ondrag: (ev: DragEvent) => any;
    innerHTML: string;
    onmouseover: (ev: MouseEvent) => any;
    lang: string;
    uniqueNumber: number;
    onpause: (ev: Event) => any;
    tagUrn: string;
    onmousedown: (ev: MouseEvent) => any;
    onclick: (ev: MouseEvent) => any;
    onwaiting: (ev: Event) => any;
    onresizestart: (ev: MSEventObj) => any;
    offsetLeft: number;
    isTextEdit: boolean;
    isDisabled: boolean;
    onpaste: (ev: DragEvent) => any;
    canHaveHTML: boolean;
    onmoveend: (ev: MSEventObj) => any;
    language: string;
    onstalled: (ev: Event) => any;
    onmousemove: (ev: MouseEvent) => any;
    style: MSStyleCSSProperties;
    isContentEditable: boolean;
    onbeforeeditfocus: (ev: MSEventObj) => any;
    onratechange: (ev: Event) => any;
    contentEditable: string;
    tabIndex: number;
    document: Document;
    onprogress: (ev: any) => any;
    ondblclick: (ev: MouseEvent) => any;
    oncontextmenu: (ev: MouseEvent) => any;
    onloadedmetadata: (ev: Event) => any;
    onafterupdate: (ev: MSEventObj) => any;
    onerror: (ev: Event) => any;
    onplay: (ev: Event) => any;
    onresizeend: (ev: MSEventObj) => any;
    onplaying: (ev: Event) => any;
    isMultiLine: boolean;
    onfocusout: (ev: FocusEvent) => any;
    onabort: (ev: UIEvent) => any;
    ondataavailable: (ev: MSEventObj) => any;
    hideFocus: boolean;
    onreadystatechange: (ev: Event) => any;
    onkeypress: (ev: KeyboardEvent) => any;
    onloadeddata: (ev: Event) => any;
    onbeforedeactivate: (ev: UIEvent) => any;
    outerText: string;
    disabled: boolean;
    onactivate: (ev: UIEvent) => any;
    accessKey: string;
    onmovestart: (ev: MSEventObj) => any;
    onselectstart: (ev: Event) => any;
    onfocus: (ev: FocusEvent) => any;
    ontimeupdate: (ev: Event) => any;
    onresize: (ev: UIEvent) => any;
    oncut: (ev: DragEvent) => any;
    onselect: (ev: UIEvent) => any;
    ondrop: (ev: DragEvent) => any;
    offsetWidth: number;
    oncopy: (ev: DragEvent) => any;
    onended: (ev: Event) => any;
    onscroll: (ev: UIEvent) => any;
    onrowenter: (ev: MSEventObj) => any;
    onload: (ev: Event) => any;
    canHaveChildren: boolean;
    oninput: (ev: Event) => any;
    dragDrop(): boolean;
    scrollIntoView(top?: boolean): void;
    addFilter(filter: Object): void;
    setCapture(containerCapture?: boolean): void;
    focus(): void;
    getAdjacentText(where: string): string;
    insertAdjacentText(where: string, text: string): void;
    getElementsByClassName(classNames: string): NodeList;
    setActive(): void;
    removeFilter(filter: Object): void;
    blur(): void;
    clearAttributes(): void;
    releaseCapture(): void;
    createControlRange(): ControlRangeCollection;
    removeBehavior(cookie: number): boolean;
    contains(child: HTMLElement): boolean;
    click(): void;
    insertAdjacentElement(position: string, insertedElement: Element): Element;
    mergeAttributes(source: HTMLElement, preserveIdentity?: boolean): void;
    replaceAdjacentText(where: string, newText: string): string;
    applyElement(apply: Element, where?: string): Element;
    addBehavior(bstrUrl: string, factory?: any): number;
    insertAdjacentHTML(where: string, html: string): void;
        
    // HTMLElement 2
    onmscontentzoom: (ev: any) => any;
    oncuechange: (ev: Event) => any;
    spellcheck: boolean;
    classList: DOMTokenList;
    onmsmanipulationstatechanged: (ev: any) => any;
    draggable: boolean;
    
    // HTMLElement 3
    dataset: DOMStringMap;
    hidden: boolean;
    msGetInputContext(): MSInputMethodContext;
        
    // HTMLElement 4
    addEventListener(type: "pointerenter", listener: (ev: PointerEvent) => any, useCapture?: boolean): void;
    addEventListener(type: "pointerout", listener: (ev: PointerEvent) => any, useCapture?: boolean): void;
    addEventListener(type: "pointerdown", listener: (ev: PointerEvent) => any, useCapture?: boolean): void;
    addEventListener(type: "pointerup", listener: (ev: PointerEvent) => any, useCapture?: boolean): void;
    addEventListener(type: "pointercancel", listener: (ev: PointerEvent) => any, useCapture?: boolean): void;
    addEventListener(type: "pointerover", listener: (ev: PointerEvent) => any, useCapture?: boolean): void;
    addEventListener(type: "pointermove", listener: (ev: PointerEvent) => any, useCapture?: boolean): void;
    addEventListener(type: "pointerleave", listener: (ev: PointerEvent) => any, useCapture?: boolean): void;
    addEventListener(type: "mspointerdown", listener: (ev: any) => any, useCapture?: boolean): void;
    addEventListener(type: "msgotpointercapture", listener: (ev: any) => any, useCapture?: boolean): void;
    addEventListener(type: "msgesturedoubletap", listener: (ev: any) => any, useCapture?: boolean): void;
    addEventListener(type: "mspointerhover", listener: (ev: any) => any, useCapture?: boolean): void;
    addEventListener(type: "msgesturehold", listener: (ev: any) => any, useCapture?: boolean): void;
    addEventListener(type: "mspointermove", listener: (ev: any) => any, useCapture?: boolean): void;
    addEventListener(type: "msgesturechange", listener: (ev: any) => any, useCapture?: boolean): void;
    addEventListener(type: "msgesturestart", listener: (ev: any) => any, useCapture?: boolean): void;
    addEventListener(type: "mspointercancel", listener: (ev: any) => any, useCapture?: boolean): void;
    addEventListener(type: "msgestureend", listener: (ev: any) => any, useCapture?: boolean): void;
    addEventListener(type: "msgesturetap", listener: (ev: any) => any, useCapture?: boolean): void;
    addEventListener(type: "mspointerout", listener: (ev: any) => any, useCapture?: boolean): void;
    addEventListener(type: "msinertiastart", listener: (ev: any) => any, useCapture?: boolean): void;
    addEventListener(type: "mslostpointercapture", listener: (ev: any) => any, useCapture?: boolean): void;
    addEventListener(type: "mspointerover", listener: (ev: any) => any, useCapture?: boolean): void;
    addEventListener(type: "mspointerup", listener: (ev: any) => any, useCapture?: boolean): void;
    addEventListener(type: "lostpointercapture", listener: (ev: PointerEvent) => any, useCapture?: boolean): void;
    addEventListener(type: "mspointerenter", listener: (ev: any) => any, useCapture?: boolean): void;
    addEventListener(type: "gotpointercapture", listener: (ev: PointerEvent) => any, useCapture?: boolean): void;
    addEventListener(type: "mspointerleave", listener: (ev: any) => any, useCapture?: boolean): void;
    addEventListener(type: "mouseleave", listener: (ev: MouseEvent) => any, useCapture?: boolean): void;
    addEventListener(type: "beforecut", listener: (ev: DragEvent) => any, useCapture?: boolean): void;
    addEventListener(type: "keydown", listener: (ev: KeyboardEvent) => any, useCapture?: boolean): void;
    addEventListener(type: "move", listener: (ev: MSEventObj) => any, useCapture?: boolean): void;
    addEventListener(type: "keyup", listener: (ev: KeyboardEvent) => any, useCapture?: boolean): void;
    addEventListener(type: "reset", listener: (ev: Event) => any, useCapture?: boolean): void;
    addEventListener(type: "help", listener: (ev: Event) => any, useCapture?: boolean): void;
    addEventListener(type: "dragleave", listener: (ev: DragEvent) => any, useCapture?: boolean): void;
    addEventListener(type: "focusin", listener: (ev: FocusEvent) => any, useCapture?: boolean): void;
    addEventListener(type: "seeked", listener: (ev: Event) => any, useCapture?: boolean): void;
    addEventListener(type: "durationchange", listener: (ev: Event) => any, useCapture?: boolean): void;
    addEventListener(type: "blur", listener: (ev: FocusEvent) => any, useCapture?: boolean): void;
    addEventListener(type: "emptied", listener: (ev: Event) => any, useCapture?: boolean): void;
    addEventListener(type: "seeking", listener: (ev: Event) => any, useCapture?: boolean): void;
    addEventListener(type: "canplay", listener: (ev: Event) => any, useCapture?: boolean): void;
    addEventListener(type: "deactivate", listener: (ev: UIEvent) => any, useCapture?: boolean): void;
    addEventListener(type: "datasetchanged", listener: (ev: MSEventObj) => any, useCapture?: boolean): void;
    addEventListener(type: "rowsdelete", listener: (ev: MSEventObj) => any, useCapture?: boolean): void;
    addEventListener(type: "loadstart", listener: (ev: Event) => any, useCapture?: boolean): void;
    addEventListener(type: "losecapture", listener: (ev: MSEventObj) => any, useCapture?: boolean): void;
    addEventListener(type: "dragenter", listener: (ev: DragEvent) => any, useCapture?: boolean): void;
    addEventListener(type: "controlselect", listener: (ev: MSEventObj) => any, useCapture?: boolean): void;
    addEventListener(type: "submit", listener: (ev: Event) => any, useCapture?: boolean): void;
    addEventListener(type: "change", listener: (ev: Event) => any, useCapture?: boolean): void;
    addEventListener(type: "layoutcomplete", listener: (ev: MSEventObj) => any, useCapture?: boolean): void;
    addEventListener(type: "beforeactivate", listener: (ev: UIEvent) => any, useCapture?: boolean): void;
    addEventListener(type: "canplaythrough", listener: (ev: Event) => any, useCapture?: boolean): void;
    addEventListener(type: "beforeupdate", listener: (ev: MSEventObj) => any, useCapture?: boolean): void;
    addEventListener(type: "filterchange", listener: (ev: MSEventObj) => any, useCapture?: boolean): void;
    addEventListener(type: "datasetcomplete", listener: (ev: MSEventObj) => any, useCapture?: boolean): void;
    addEventListener(type: "suspend", listener: (ev: Event) => any, useCapture?: boolean): void;
    addEventListener(type: "mouseenter", listener: (ev: MouseEvent) => any, useCapture?: boolean): void;
    addEventListener(type: "errorupdate", listener: (ev: MSEventObj) => any, useCapture?: boolean): void;
    addEventListener(type: "mouseout", listener: (ev: MouseEvent) => any, useCapture?: boolean): void;
    addEventListener(type: "mousewheel", listener: (ev: MouseWheelEvent) => any, useCapture?: boolean): void;
    addEventListener(type: "volumechange", listener: (ev: Event) => any, useCapture?: boolean): void;
    addEventListener(type: "cellchange", listener: (ev: MSEventObj) => any, useCapture?: boolean): void;
    addEventListener(type: "rowexit", listener: (ev: MSEventObj) => any, useCapture?: boolean): void;
    addEventListener(type: "rowsinserted", listener: (ev: MSEventObj) => any, useCapture?: boolean): void;
    addEventListener(type: "propertychange", listener: (ev: MSEventObj) => any, useCapture?: boolean): void;
    addEventListener(type: "dragend", listener: (ev: DragEvent) => any, useCapture?: boolean): void;
    addEventListener(type: "beforepaste", listener: (ev: DragEvent) => any, useCapture?: boolean): void;
    addEventListener(type: "dragover", listener: (ev: DragEvent) => any, useCapture?: boolean): void;
    addEventListener(type: "mouseup", listener: (ev: MouseEvent) => any, useCapture?: boolean): void;
    addEventListener(type: "dragstart", listener: (ev: DragEvent) => any, useCapture?: boolean): void;
    addEventListener(type: "beforecopy", listener: (ev: DragEvent) => any, useCapture?: boolean): void;
    addEventListener(type: "drag", listener: (ev: DragEvent) => any, useCapture?: boolean): void;
    addEventListener(type: "mouseover", listener: (ev: MouseEvent) => any, useCapture?: boolean): void;
    addEventListener(type: "pause", listener: (ev: Event) => any, useCapture?: boolean): void;
    addEventListener(type: "mousedown", listener: (ev: MouseEvent) => any, useCapture?: boolean): void;
    addEventListener(type: "click", listener: (ev: MouseEvent) => any, useCapture?: boolean): void;
    addEventListener(type: "waiting", listener: (ev: Event) => any, useCapture?: boolean): void;
    addEventListener(type: "resizestart", listener: (ev: MSEventObj) => any, useCapture?: boolean): void;
    addEventListener(type: "paste", listener: (ev: DragEvent) => any, useCapture?: boolean): void;
    addEventListener(type: "moveend", listener: (ev: MSEventObj) => any, useCapture?: boolean): void;
    addEventListener(type: "stalled", listener: (ev: Event) => any, useCapture?: boolean): void;
    addEventListener(type: "mousemove", listener: (ev: MouseEvent) => any, useCapture?: boolean): void;
    addEventListener(type: "beforeeditfocus", listener: (ev: MSEventObj) => any, useCapture?: boolean): void;
    addEventListener(type: "ratechange", listener: (ev: Event) => any, useCapture?: boolean): void;
    addEventListener(type: "progress", listener: (ev: ProgressEvent) => any, useCapture?: boolean): void;
    addEventListener(type: "dblclick", listener: (ev: MouseEvent) => any, useCapture?: boolean): void;
    addEventListener(type: "contextmenu", listener: (ev: MouseEvent) => any, useCapture?: boolean): void;
    addEventListener(type: "loadedmetadata", listener: (ev: Event) => any, useCapture?: boolean): void;
    addEventListener(type: "afterupdate", listener: (ev: MSEventObj) => any, useCapture?: boolean): void;
    addEventListener(type: "error", listener: (ev: ErrorEvent) => any, useCapture?: boolean): void;
    addEventListener(type: "play", listener: (ev: Event) => any, useCapture?: boolean): void;
    addEventListener(type: "resizeend", listener: (ev: MSEventObj) => any, useCapture?: boolean): void;
    addEventListener(type: "playing", listener: (ev: Event) => any, useCapture?: boolean): void;
    addEventListener(type: "focusout", listener: (ev: FocusEvent) => any, useCapture?: boolean): void;
    addEventListener(type: "abort", listener: (ev: UIEvent) => any, useCapture?: boolean): void;
    addEventListener(type: "dataavailable", listener: (ev: MSEventObj) => any, useCapture?: boolean): void;
    addEventListener(type: "readystatechange", listener: (ev: Event) => any, useCapture?: boolean): void;
    addEventListener(type: "keypress", listener: (ev: KeyboardEvent) => any, useCapture?: boolean): void;
    addEventListener(type: "loadeddata", listener: (ev: Event) => any, useCapture?: boolean): void;
    addEventListener(type: "beforedeactivate", listener: (ev: UIEvent) => any, useCapture?: boolean): void;
    addEventListener(type: "activate", listener: (ev: UIEvent) => any, useCapture?: boolean): void;
    addEventListener(type: "movestart", listener: (ev: MSEventObj) => any, useCapture?: boolean): void;
    addEventListener(type: "selectstart", listener: (ev: Event) => any, useCapture?: boolean): void;
    addEventListener(type: "focus", listener: (ev: FocusEvent) => any, useCapture?: boolean): void;
    addEventListener(type: "timeupdate", listener: (ev: Event) => any, useCapture?: boolean): void;
    addEventListener(type: "resize", listener: (ev: UIEvent) => any, useCapture?: boolean): void;
    addEventListener(type: "cut", listener: (ev: DragEvent) => any, useCapture?: boolean): void;
    addEventListener(type: "select", listener: (ev: UIEvent) => any, useCapture?: boolean): void;
    addEventListener(type: "drop", listener: (ev: DragEvent) => any, useCapture?: boolean): void;
    addEventListener(type: "copy", listener: (ev: DragEvent) => any, useCapture?: boolean): void;
    addEventListener(type: "ended", listener: (ev: Event) => any, useCapture?: boolean): void;
    addEventListener(type: "scroll", listener: (ev: UIEvent) => any, useCapture?: boolean): void;
    addEventListener(type: "rowenter", listener: (ev: MSEventObj) => any, useCapture?: boolean): void;
    addEventListener(type: "load", listener: (ev: Event) => any, useCapture?: boolean): void;
    addEventListener(type: "input", listener: (ev: Event) => any, useCapture?: boolean): void;
    addEventListener(type: "mscontentzoom", listener: (ev: MSEventObj) => any, useCapture?: boolean): void;
    addEventListener(type: "cuechange", listener: (ev: Event) => any, useCapture?: boolean): void;
    addEventListener(type: "msmanipulationstatechanged", listener: (ev: any) => any, useCapture?: boolean): void;
    addEventListener(type: string, listener: EventListener, useCapture?: boolean): void;
        
    // interface Element extends Node, NodeSelector, ElementTraversal {
    scrollTop: number;
    clientLeft: number;
    scrollLeft: number;
    tagName: string;
    clientWidth: number;
    scrollWidth: number;
    clientHeight: number;
    clientTop: number;
    scrollHeight: number;
    getAttribute(name?: string): string;
    getElementsByTagNameNS(namespaceURI: string, localName: string): NodeList;
    hasAttributeNS(namespaceURI: string, localName: string): boolean;
    getBoundingClientRect(): ClientRect;
    getAttributeNS(namespaceURI: string, localName: string): string;
    getAttributeNodeNS(namespaceURI: string, localName: string): Attr;
    setAttributeNodeNS(newAttr: Attr): Attr;
    msMatchesSelector(selectors: string): boolean;
    hasAttribute(name: string): boolean;
    removeAttribute(name?: string): void;
    setAttributeNS(namespaceURI: string, qualifiedName: string, value: string): void;
    getAttributeNode(name: string): Attr;
    fireEvent(eventName: string, eventObj?: any): boolean;
    getElementsByTagName(name: "a"): NodeListOf<HTMLAnchorElement>;
    getElementsByTagName(name: "abbr"): NodeListOf<HTMLElement>;
    getElementsByTagName(name: "address"): NodeListOf<HTMLElement>;
    getElementsByTagName(name: "area"): NodeListOf<HTMLAreaElement>;
    getElementsByTagName(name: "article"): NodeListOf<HTMLElement>;
    getElementsByTagName(name: "aside"): NodeListOf<HTMLElement>;
    getElementsByTagName(name: "audio"): NodeListOf<HTMLAudioElement>;
    getElementsByTagName(name: "b"): NodeListOf<HTMLElement>;
    getElementsByTagName(name: "base"): NodeListOf<HTMLBaseElement>;
    getElementsByTagName(name: "bdi"): NodeListOf<HTMLElement>;
    getElementsByTagName(name: "bdo"): NodeListOf<HTMLElement>;
    getElementsByTagName(name: "blockquote"): NodeListOf<HTMLQuoteElement>;
    getElementsByTagName(name: "body"): NodeListOf<HTMLBodyElement>;
    getElementsByTagName(name: "br"): NodeListOf<HTMLBRElement>;
    getElementsByTagName(name: "button"): NodeListOf<HTMLButtonElement>;
    getElementsByTagName(name: "canvas"): NodeListOf<HTMLCanvasElement>;
    getElementsByTagName(name: "caption"): NodeListOf<HTMLTableCaptionElement>;
    getElementsByTagName(name: "cite"): NodeListOf<HTMLElement>;
    getElementsByTagName(name: "code"): NodeListOf<HTMLElement>;
    getElementsByTagName(name: "col"): NodeListOf<HTMLTableColElement>;
    getElementsByTagName(name: "colgroup"): NodeListOf<HTMLTableColElement>;
    getElementsByTagName(name: "datalist"): NodeListOf<HTMLDataListElement>;
    getElementsByTagName(name: "dd"): NodeListOf<HTMLElement>;
    getElementsByTagName(name: "del"): NodeListOf<HTMLModElement>;
    getElementsByTagName(name: "dfn"): NodeListOf<HTMLElement>;
    getElementsByTagName(name: "div"): NodeListOf<HTMLDivElement>;
    getElementsByTagName(name: "dl"): NodeListOf<HTMLDListElement>;
    getElementsByTagName(name: "dt"): NodeListOf<HTMLElement>;
    getElementsByTagName(name: "em"): NodeListOf<HTMLElement>;
    getElementsByTagName(name: "embed"): NodeListOf<HTMLEmbedElement>;
    getElementsByTagName(name: "fieldset"): NodeListOf<HTMLFieldSetElement>;
    getElementsByTagName(name: "figcaption"): NodeListOf<HTMLElement>;
    getElementsByTagName(name: "figure"): NodeListOf<HTMLElement>;
    getElementsByTagName(name: "footer"): NodeListOf<HTMLElement>;
    getElementsByTagName(name: "form"): NodeListOf<HTMLFormElement>;
    getElementsByTagName(name: "h1"): NodeListOf<HTMLHeadingElement>;
    getElementsByTagName(name: "h2"): NodeListOf<HTMLHeadingElement>;
    getElementsByTagName(name: "h3"): NodeListOf<HTMLHeadingElement>;
    getElementsByTagName(name: "h4"): NodeListOf<HTMLHeadingElement>;
    getElementsByTagName(name: "h5"): NodeListOf<HTMLHeadingElement>;
    getElementsByTagName(name: "h6"): NodeListOf<HTMLHeadingElement>;
    getElementsByTagName(name: "head"): NodeListOf<HTMLHeadElement>;
    getElementsByTagName(name: "header"): NodeListOf<HTMLElement>;
    getElementsByTagName(name: "hgroup"): NodeListOf<HTMLElement>;
    getElementsByTagName(name: "hr"): NodeListOf<HTMLHRElement>;
    getElementsByTagName(name: "html"): NodeListOf<HTMLHtmlElement>;
    getElementsByTagName(name: "i"): NodeListOf<HTMLElement>;
    getElementsByTagName(name: "iframe"): NodeListOf<HTMLIFrameElement>;
    getElementsByTagName(name: "img"): NodeListOf<HTMLImageElement>;
    getElementsByTagName(name: "input"): NodeListOf<HTMLInputElement>;
    getElementsByTagName(name: "ins"): NodeListOf<HTMLModElement>;
    getElementsByTagName(name: "kbd"): NodeListOf<HTMLElement>;
    getElementsByTagName(name: "label"): NodeListOf<HTMLLabelElement>;
    getElementsByTagName(name: "legend"): NodeListOf<HTMLLegendElement>;
    getElementsByTagName(name: "li"): NodeListOf<HTMLLIElement>;
    getElementsByTagName(name: "link"): NodeListOf<HTMLLinkElement>;
    getElementsByTagName(name: "main"): NodeListOf<HTMLElement>;
    getElementsByTagName(name: "map"): NodeListOf<HTMLMapElement>;
    getElementsByTagName(name: "mark"): NodeListOf<HTMLElement>;
    getElementsByTagName(name: "menu"): NodeListOf<HTMLMenuElement>;
    getElementsByTagName(name: "meta"): NodeListOf<HTMLMetaElement>;
    getElementsByTagName(name: "nav"): NodeListOf<HTMLElement>;
    getElementsByTagName(name: "noscript"): NodeListOf<HTMLElement>;
    getElementsByTagName(name: "object"): NodeListOf<HTMLObjectElement>;
    getElementsByTagName(name: "ol"): NodeListOf<HTMLOListElement>;
    getElementsByTagName(name: "optgroup"): NodeListOf<HTMLOptGroupElement>;
    getElementsByTagName(name: "option"): NodeListOf<HTMLOptionElement>;
    getElementsByTagName(name: "p"): NodeListOf<HTMLParagraphElement>;
    getElementsByTagName(name: "param"): NodeListOf<HTMLParamElement>;
    getElementsByTagName(name: "pre"): NodeListOf<HTMLPreElement>;
    getElementsByTagName(name: "progress"): NodeListOf<HTMLProgressElement>;
    getElementsByTagName(name: "q"): NodeListOf<HTMLQuoteElement>;
    getElementsByTagName(name: "rp"): NodeListOf<HTMLElement>;
    getElementsByTagName(name: "rt"): NodeListOf<HTMLElement>;
    getElementsByTagName(name: "ruby"): NodeListOf<HTMLElement>;
    getElementsByTagName(name: "s"): NodeListOf<HTMLElement>;
    getElementsByTagName(name: "samp"): NodeListOf<HTMLElement>;
    getElementsByTagName(name: "script"): NodeListOf<HTMLScriptElement>;
    getElementsByTagName(name: "section"): NodeListOf<HTMLElement>;
    getElementsByTagName(name: "select"): NodeListOf<HTMLSelectElement>;
    getElementsByTagName(name: "small"): NodeListOf<HTMLElement>;
    getElementsByTagName(name: "source"): NodeListOf<HTMLSourceElement>;
    getElementsByTagName(name: "span"): NodeListOf<HTMLSpanElement>;
    getElementsByTagName(name: "strong"): NodeListOf<HTMLElement>;
    getElementsByTagName(name: "style"): NodeListOf<HTMLStyleElement>;
    getElementsByTagName(name: "sub"): NodeListOf<HTMLElement>;
    getElementsByTagName(name: "summary"): NodeListOf<HTMLElement>;
    getElementsByTagName(name: "sup"): NodeListOf<HTMLElement>;
    getElementsByTagName(name: "table"): NodeListOf<HTMLTableElement>;
    getElementsByTagName(name: "tbody"): NodeListOf<HTMLTableSectionElement>;
    getElementsByTagName(name: "td"): NodeListOf<HTMLTableDataCellElement>;
    getElementsByTagName(name: "textarea"): NodeListOf<HTMLTextAreaElement>;
    getElementsByTagName(name: "tfoot"): NodeListOf<HTMLTableSectionElement>;
    getElementsByTagName(name: "th"): NodeListOf<HTMLTableHeaderCellElement>;
    getElementsByTagName(name: "thead"): NodeListOf<HTMLTableSectionElement>;
    getElementsByTagName(name: "title"): NodeListOf<HTMLTitleElement>;
    getElementsByTagName(name: "tr"): NodeListOf<HTMLTableRowElement>;
    getElementsByTagName(name: "track"): NodeListOf<HTMLTrackElement>;
    getElementsByTagName(name: "u"): NodeListOf<HTMLElement>;
    getElementsByTagName(name: "ul"): NodeListOf<HTMLUListElement>;
    getElementsByTagName(name: "var"): NodeListOf<HTMLElement>;
    getElementsByTagName(name: "video"): NodeListOf<HTMLVideoElement>;
    getElementsByTagName(name: "wbr"): NodeListOf<HTMLElement>;
    getElementsByTagName(name: string): NodeList;
    getClientRects(): ClientRectList;
    setAttributeNode(newAttr: Attr): Attr;
    removeAttributeNode(oldAttr: Attr): Attr;
    setAttribute(name?: string, value?: string): void;
    removeAttributeNS(namespaceURI: string, localName: string): void;

    // interface Element extends GlobalEventHandlers {
    onlostpointercapture: (ev: PointerEvent) => any;
    onmspointerenter: (ev: any) => any;
    ongotpointercapture: (ev: PointerEvent) => any;
    onmspointerleave: (ev: any) => any;
    msZoomTo(args: MsZoomToOptions): void;
    setPointerCapture(pointerId: number): void;
    msGetUntransformedBounds(): ClientRect;
    releasePointerCapture(pointerId: number): void;
    msRequestFullscreen(): void;
        
    // interface GlobalEventHandlers {
    onpointerenter: (ev: PointerEvent) => any;
    onpointerout: (ev: PointerEvent) => any;
    onpointerdown: (ev: PointerEvent) => any;
    onpointerup: (ev: PointerEvent) => any;
    onpointercancel: (ev: PointerEvent) => any;
    onpointerover: (ev: PointerEvent) => any;
    onpointermove: (ev: PointerEvent) => any;
    onpointerleave: (ev: PointerEvent) => any;
        
    // interface Element {
    msRegionOverflow: string;
    onmspointerdown: (ev: any) => any;
    onmsgotpointercapture: (ev: any) => any;
    onmsgesturedoubletap: (ev: any) => any;
    onmspointerhover: (ev: any) => any;
    onmsgesturehold: (ev: any) => any;
    onmspointermove: (ev: any) => any;
    onmsgesturechange: (ev: any) => any;
    onmsgesturestart: (ev: any) => any;
    onmspointercancel: (ev: any) => any;
    onmsgestureend: (ev: any) => any;
    onmsgesturetap: (ev: any) => any;
    onmspointerout: (ev: any) => any;
    onmsinertiastart: (ev: any) => any;
    onmslostpointercapture: (ev: any) => any;
    onmspointerover: (ev: any) => any;
    msContentZoomFactor: number;
    onmspointerup: (ev: any) => any;
    msGetRegionContent(): MSRangeCollection;
    msReleasePointerCapture(pointerId: number): void;
    msSetPointerCapture(pointerId: number): void;
        
    // interface Node extends EventTarget {
    nodeType: number;
    previousSibling: Node;
    localName: string;
    namespaceURI: string;
    textContent: string;
    parentNode: Node;
    nextSibling: Node;
    nodeValue: string;
    lastChild: Node;
    childNodes: NodeList;
    nodeName: string;
    ownerDocument: Document;
    attributes: NamedNodeMap;
    firstChild: Node;
    prefix: string;
    removeChild(oldChild: Node): Node;
    appendChild(newChild: Node): Node;
    isSupported(feature: string, version: string): boolean;
    isEqualNode(arg: Node): boolean;
    lookupPrefix(namespaceURI: string): string;
    isDefaultNamespace(namespaceURI: string): boolean;
    compareDocumentPosition(other: Node): number;
    normalize(): void;
    isSameNode(other: Node): boolean;
    hasAttributes(): boolean;
    lookupNamespaceURI(prefix: string): string;
    cloneNode(deep?: boolean): Node;
    hasChildNodes(): boolean;
    replaceChild(newChild: Node, oldChild: Node): Node;
    insertBefore(newChild: Node, refChild?: Node): Node;
    ENTITY_REFERENCE_NODE: number;
    ATTRIBUTE_NODE: number;
    DOCUMENT_FRAGMENT_NODE: number;
    TEXT_NODE: number;
    ELEMENT_NODE: number;
    COMMENT_NODE: number;
    DOCUMENT_POSITION_DISCONNECTED: number;
    DOCUMENT_POSITION_CONTAINED_BY: number;
    DOCUMENT_POSITION_CONTAINS: number;
    DOCUMENT_TYPE_NODE: number;
    DOCUMENT_POSITION_IMPLEMENTATION_SPECIFIC: number;
    DOCUMENT_NODE: number;
    ENTITY_NODE: number;
    PROCESSING_INSTRUCTION_NODE: number;
    CDATA_SECTION_NODE: number;
    NOTATION_NODE: number;
    DOCUMENT_POSITION_FOLLOWING: number;
    DOCUMENT_POSITION_PRECEDING: number;
    
    // interface EventTarget {
    //addEventListener(type: string, listener: EventListener, useCapture?: boolean): void;
    removeEventListener(type: string, listener: EventListener, useCapture?: boolean): void;
    dispatchEvent(evt: Event): boolean;
        
    // interface NodeSelector {
    querySelectorAll(selectors: string): NodeList;
    querySelector(selectors: string): Element;
        
    // interface ElementTraversal {
    childElementCount: number;
    previousElementSibling: Element;
    lastElementChild: Element;
    nextElementSibling: Element;
    firstElementChild: Element;

    // interface ElementCSSInlineStyle {
    runtimeStyle: MSStyleCSSProperties;
    currentStyle: MSCurrentStyleCSSProperties;
    doScroll(component?: any): void;
    componentFromPoint(x: number, y: number): string;
        
    // interface MSEventAttachmentTarget {
    attachEvent(event: string, listener: EventListener): boolean;
    detachEvent(event: string, listener: EventListener): void;
        
    // interface MSNodeExtensions {
    swapNode(otherNode: Node): Node;
    removeNode(deep?: boolean): Node;
    replaceNode(replacement: Node): Node;
}

export class CustomHTMLElement extends BaseCustomHTMLElement {
}

export function register(name: string, klass: any) {
    delete klass.prototype['constructor'];
    (<any> document).registerElement(name, {
        prototype : klass.prototype
    });
}

index.html

<!doctype html>
<html>
<head>
<meta charset="UTF-8" />
<!-- HACK! To allow normal inheritance in TypeScript -->
<script>BaseCustomHTMLElement = window.HTMLElement</script>

<!-- DOWNLOAD REQUIRE.JS! -->
<script src="require.js"></script>
<script src="index.js"></script>
</head>
<body>
    <example-element>Yello!</example-element>
</body>
</html>

index.ts

import myelement = require('./MyElement');

// Register required since TypeScript omits unused imports, so we have to introduce explicit registration
myelement.register(); 

var t = document.querySelector("example-element");
t.myTest();

MyElement.ts

import customelement = require('./customelement');

export class MyElement extends customelement.CustomHTMLElement {
    public myTest() {
        // "this" is fully qualified, includes all methods e.g. addEventListener, dispatchEvent
        console.log("this", this);
        console.dir(this);
    }
}

export function register() {
    customelement.register("example-element", MyElement);
}

Warning: May contain typos, I didn't try exactly this code.

Also add custom-elements.min.js for document.registerElement as a polyfill for older browsers if you want from here: https://www.npmjs.org/package/custom-elements

I hereby place this code in public domain

Update. The following just works now 🌹 microsoft/TypeScript#574 (comment)

class MyComponent extends HTMLElement {    
}

@basarat: I've just arrived here via microsoft/TypeScript#1168, and it looks like I still need this gist when using tsc 1.7.5.

The following:

interface Document {
    registerElement(tagName: string, implementation: HTMLElement );
}

class MyList extends HTMLElement {
}

document.registerElement('my-list', MyList);

gives me:

Argument of type 'typeof MyList' is not assignable to parameter of type 'HTMLElement'.
  Property 'accessKey' is missing in type 'typeof MyList'.