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, 10 insertions, 10 deletions

diff --git a/cli/js/lib.deno.window.d.ts b/cli/js/lib.deno.window.d.ts
index 2b8e6f50f..6377057d3 100644
--- a/cli/js/lib.deno.window.d.ts
+++ b/cli/js/lib.deno.window.d.ts
@@ -1,28 +1,28 @@
 // Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
 
-/* eslint-disable @typescript-eslint/no-unused-vars, @typescript-eslint/no-empty-interface, @typescript-eslint/no-explicit-any */
+/* eslint-disable @typescript-eslint/no-explicit-any */
 
 /// <reference no-default-lib="true" />
 /// <reference lib="deno.ns" />
 /// <reference lib="deno.shared_globals" />
 /// <reference lib="esnext" />
 
-declare interface Window {
-  window: Window & typeof globalThis;
-  self: Window & typeof globalThis;
-  onload: Function | undefined;
-  onunload: Function | undefined;
+declare interface Window extends EventTarget {
+  readonly window: Window & typeof globalThis;
+  readonly self: Window & typeof globalThis;
+  onload: ((this: Window, ev: Event) => any) | null;
+  onunload: ((this: Window, ev: Event) => any) | null;
   location: Location;
   crypto: Crypto;
   close: () => void;
-  closed: boolean;
+  readonly closed: boolean;
   Deno: typeof Deno;
 }
 
 declare const window: Window & typeof globalThis;
 declare const self: Window & typeof globalThis;
-declare const onload: Function | undefined;
-declare const onunload: Function | undefined;
+declare const onload: ((this: Window, ev: Event) => any) | null;
+declare const onunload: ((this: Window, ev: Event) => any) | null;
 declare const crypto: Crypto;
 
 declare interface Crypto {
@@ -45,4 +45,4 @@ declare interface Crypto {
   ): T;
 }
 
-/* eslint-enable @typescript-eslint/no-unused-vars, @typescript-eslint/no-empty-interface, @typescript-eslint/no-explicit-any */
+/* eslint-enable @typescript-eslint/no-explicit-any */