1 files changed, 159 insertions, 0 deletions
diff --git a/packages/webapi/src/lib/Document.ts b/packages/webapi/src/lib/Document.ts
new file mode 100644
index 000000000..867cc4448
--- /dev/null
+++ b/packages/webapi/src/lib/Document.ts
@@ -0,0 +1,159 @@
+import * as _ from './utils'
+import { Text } from './CharacterData'
+import { TreeWalker } from './TreeWalker'
+
+export class Document extends Node {
+	createElement(name: string) {
+		const internals = _.internalsOf<DocumentInternals>(this, 'Document', 'createElement')
+
+		const customElementInternals: CustomElementRegistryInternals = _.INTERNALS.get(internals.target.customElements)
+
+		name = String(name).toLowerCase()
+
+		const TypeOfHTMLElement = internals.constructorByName.get(name) || (customElementInternals && customElementInternals.constructorByName.get(name)) || HTMLUnknownElement
+
+		const element = Object.setPrototypeOf(new EventTarget(), TypeOfHTMLElement.prototype) as HTMLElement
+
+		_.INTERNALS.set(element, {
+			attributes: {},
+			localName: name,
+			ownerDocument: this,
+			shadowInit: null as unknown as ShadowRootInit,
+			shadowRoot: null as unknown as ShadowRoot,
+		} as ElementInternals)
+
+		return element
+	}
+
+	createNodeIterator(root: Node, whatToShow: number = NodeFilter.SHOW_ALL, filter?: NodeIteratorInternals['filter']) {
+		const target = Object.create(NodeIterator.prototype)
+
+		_.INTERNALS.set(target, { filter, pointerBeforeReferenceNode: false, referenceNode: root, root, whatToShow } as NodeIteratorInternals)
+
+		return target
+	}
+
+	createTextNode(data: string) {
+		return new Text(data)
+	}
+
+	createTreeWalker(root: Node, whatToShow: number = NodeFilter.SHOW_ALL, filter?: NodeFilter, expandEntityReferences?: boolean) {
+		const target = Object.create(TreeWalker.prototype)
+
+		_.INTERNALS.set(target, { filter, currentNode: root, root, whatToShow } as TreeWalkerInternals)
+
+		return target
+	}
+
+	get adoptedStyleSheets(): StyleSheet[] {
+		return []
+	}
+
+	get styleSheets(): StyleSheet[] {
+		return []
+	}
+
+	body!: HTMLBodyElement
+	documentElement!: HTMLHtmlElement
+	head!: HTMLHeadElement
+}
+
+export class HTMLDocument extends Document {}
+
+_.allowStringTag(Document)
+_.allowStringTag(HTMLDocument)
+
+export const initDocument = (target: Target, exclude: Set<string>) => {
+	if (exclude.has('document')) return
+
+	const EventTarget = target.EventTarget || globalThis.EventTarget
+	const HTMLDocument = target.HTMLDocument || globalThis.HTMLDocument
+
+	const document: HTMLDocument = target.document = Object.setPrototypeOf(new EventTarget(), HTMLDocument.prototype)
+
+	_.INTERNALS.set(document, {
+		target,
+		constructorByName: new Map<string, Function>([
+			['body', target.HTMLBodyElement],
+			['canvas', target.HTMLCanvasElement],
+			['div', target.HTMLDivElement],
+			['head', target.HTMLHeadElement],
+			['html', target.HTMLHtmlElement],
+			['img', target.HTMLImageElement],
+			['span', target.HTMLSpanElement],
+			['style', target.HTMLStyleElement],
+		]),
+		nameByConstructor: new Map,
+	} as DocumentInternals)
+
+	const initElement = (name: string, Class: Function) => {
+		const target = Object.setPrototypeOf(new EventTarget(), Class.prototype)
+
+		_.INTERNALS.set(target, {
+			attributes: {},
+			localName: name,
+			ownerDocument: document,
+			shadowRoot: null as unknown as ShadowRoot,
+			shadowInit: null as unknown as ShadowRootInit,
+		} as ElementInternals)
+
+		return target
+	}
+
+	document.body = initElement('body', target.HTMLBodyElement) as HTMLBodyElement
+	document.head = initElement('head', target.HTMLHeadElement) as HTMLHeadElement
+	document.documentElement = initElement('html', target.HTMLHtmlElement) as HTMLHtmlElement
+}
+
+interface DocumentInternals {
+	body: HTMLBodyElement
+	documentElement: HTMLHtmlElement
+	head: HTMLHeadElement
+	constructorByName: Map<string, Function>
+	nameByConstructor: Map<Function, string>
+	target: Target
+}
+
+interface CustomElementRegistryInternals {
+	constructorByName: Map<string, Function>
+	nameByConstructor: Map<Function, string>
+}
+
+interface ElementInternals {
+	attributes: { [name: string]: string },
+	localName: string
+	ownerDocument: Document
+	shadowRoot: ShadowRoot
+	shadowInit: ShadowRootInit
+}
+
+interface ShadowRootInit extends Record<any, any> {
+	mode?: string
+}
+
+interface Target extends Record<any, any> {
+	HTMLBodyElement: typeof HTMLBodyElement
+	HTMLDivElement: typeof HTMLDivElement
+	HTMLElement: typeof HTMLElement
+	HTMLHeadElement: typeof HTMLHeadElement
+	HTMLHtmlElement: typeof HTMLHtmlElement
+	HTMLSpanElement: typeof HTMLSpanElement
+	HTMLStyleElement: typeof HTMLStyleElement
+	customElements: CustomElementRegistry
+	document: DocumentInternals
+}
+
+interface NodeIteratorInternals {
+	filter: NodeFilter
+	pointerBeforeReferenceNode: boolean
+	referenceNode: Node
+	root: Node
+	whatToShow: number
+}
+
+interface TreeWalkerInternals {
+	filter: NodeFilter
+	currentNode: Node
+	root: Node
+	whatToShow: number
+}