fix(unstable): Honor granular unstable flags in js runtime (#21466)

This fixes #21434 for `BroadcastChannel` and `WebSocketStream`.
`--unstable` still enable both, but granular unstable flags now also
work:

* `--unstable-net` now enables `WebSocketStream`.
* `--unstable-broadcast-channel` now enables `BroadcastChannel`.
* Additionally, there are now tests for all granular unstable flags.
Since `unsafe-proto` already had tests, so I didn't add any for this
one.

It also introduces a map to keep track of granular unstable ids without
having to sync multiple places.

1 files changed, 6 insertions, 2 deletions

diff --git a/runtime/js/98_global_scope.js b/runtime/js/98_global_scope.js
index 56354948e..65a9c6933 100644
--- a/runtime/js/98_global_scope.js
+++ b/runtime/js/98_global_scope.js
@@ -42,6 +42,7 @@ import * as globalInterfaces from "ext:deno_web/04_global_interfaces.js";
 import * as webStorage from "ext:deno_webstorage/01_webstorage.js";
 import * as prompt from "ext:runtime/41_prompt.js";
 import * as imageData from "ext:deno_web/16_image_data.js";
+import { unstableIds } from "ext:runtime/90_deno_ns.js";
 
 // https://developer.mozilla.org/en-US/docs/Web/API/WindowOrWorkerGlobalScope
 const windowOrWorkerGlobalScope = {
@@ -143,8 +144,11 @@ const windowOrWorkerGlobalScope = {
   [webidl.brand]: util.nonEnumerable(webidl.brand),
 };
 
-const unstableWindowOrWorkerGlobalScope = {
+const unstableForWindowOrWorkerGlobalScope = {};
+unstableForWindowOrWorkerGlobalScope[unstableIds.broadcastChannel] = {
   BroadcastChannel: util.nonEnumerable(broadcastChannel.BroadcastChannel),
+};
+unstableForWindowOrWorkerGlobalScope[unstableIds.net] = {
   WebSocketStream: util.nonEnumerable(webSocketStream.WebSocketStream),
 };
 
@@ -312,7 +316,7 @@ const workerRuntimeGlobalProperties = {
 export {
   mainRuntimeGlobalProperties,
   memoizeLazy,
-  unstableWindowOrWorkerGlobalScope,
+  unstableForWindowOrWorkerGlobalScope,
   windowOrWorkerGlobalScope,
   workerRuntimeGlobalProperties,
 };