refactor: Event and EventTarget implementations (#4707)

Refactors Event and EventTarget so that they better encapsulate their
non-public data as well as are more forward compatible with things like
DOM Nodes.

Moves `dom_types.ts` -> `dom_types.d.ts` which was always the intention,
it was a legacy of when we used to build the types from the code and the
limitations of the compiler.  There was a lot of cruft in `dom_types`
which shouldn't have been there, and mis-alignment to the DOM standards.
This generally has been eliminated, though we still have some minor
differences from the DOM (like the removal of some deprecated
methods/properties).

Adds `DOMException`.  Strictly it shouldn't inherit from `Error`, but
most browsers provide a stack trace when one is thrown, so the behaviour
in Deno actually better matches the browser.

`Event` still doesn't log to console like it does in the browser.  I
 wanted to get this raised and that could be an enhancement later on (it
 currently doesn't either).

1 files changed, 3 insertions, 85 deletions

diff --git a/cli/js/web/dom_util.ts b/cli/js/web/dom_util.ts
index 40a8c618f..d12593e8e 100644
--- a/cli/js/web/dom_util.ts
+++ b/cli/js/web/dom_util.ts
@@ -1,6 +1,6 @@
 // Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
-// Utility functions for DOM nodes
-import * as domTypes from "./dom_types.ts";
+
+import * as domTypes from "./dom_types.d.ts";
 
 export function getDOMStringList(arr: string[]): domTypes.DOMStringList {
   Object.defineProperties(arr, {
@@ -16,87 +16,5 @@ export function getDOMStringList(arr: string[]): domTypes.DOMStringList {
       },
     },
   });
-  return (arr as unknown) as domTypes.DOMStringList;
-}
-
-export function isNode(nodeImpl: domTypes.EventTarget | null): boolean {
-  return Boolean(nodeImpl && "nodeType" in nodeImpl);
-}
-
-export function isShadowRoot(nodeImpl: domTypes.EventTarget | null): boolean {
-  return Boolean(
-    nodeImpl &&
-      nodeImpl[domTypes.eventTargetNodeType] ===
-        domTypes.NodeType.DOCUMENT_FRAGMENT_NODE &&
-      nodeImpl[domTypes.eventTargetHost] != null
-  );
-}
-
-export function isSlotable(nodeImpl: domTypes.EventTarget | null): boolean {
-  return Boolean(
-    nodeImpl &&
-      (nodeImpl[domTypes.eventTargetNodeType] ===
-        domTypes.NodeType.ELEMENT_NODE ||
-        nodeImpl[domTypes.eventTargetNodeType] === domTypes.NodeType.TEXT_NODE)
-  );
-}
-
-// https://dom.spec.whatwg.org/#node-trees
-// const domSymbolTree = Symbol("DOM Symbol Tree");
-
-// https://dom.spec.whatwg.org/#concept-shadow-including-inclusive-ancestor
-export function isShadowInclusiveAncestor(
-  ancestor: domTypes.EventTarget | null,
-  node: domTypes.EventTarget | null
-): boolean {
-  while (isNode(node)) {
-    if (node === ancestor) {
-      return true;
-    }
-
-    if (isShadowRoot(node)) {
-      node = node && node[domTypes.eventTargetHost];
-    } else {
-      node = null; // domSymbolTree.parent(node);
-    }
-  }
-
-  return false;
-}
-
-export function getRoot(
-  node: domTypes.EventTarget | null
-): domTypes.EventTarget | null {
-  const root = node;
-
-  // for (const ancestor of domSymbolTree.ancestorsIterator(node)) {
-  //   root = ancestor;
-  // }
-
-  return root;
-}
-
-// https://dom.spec.whatwg.org/#retarget
-export function retarget(
-  a: domTypes.EventTarget | null,
-  b: domTypes.EventTarget
-): domTypes.EventTarget | null {
-  while (true) {
-    if (!isNode(a)) {
-      return a;
-    }
-
-    const aRoot = getRoot(a);
-
-    if (aRoot) {
-      if (
-        !isShadowRoot(aRoot) ||
-        (isNode(b) && isShadowInclusiveAncestor(aRoot, b))
-      ) {
-        return a;
-      }
-
-      a = aRoot[domTypes.eventTargetHost];
-    }
-  }
+  return arr as string[] & domTypes.DOMStringList;
 }