Remove usage of Promise.withResolvers.

See #409

This is now tested indirectly through transitive imports via `src/bin` type checking.

Author: lgarron

src/cubing/twisty/views/InitialValueTracker.ts

@@ -1,12 +1,14 @@
 export class InitialValueTracker<T> {
+  // @ts-expect-error: We do initialize this synchronously (assuming no one has tampered with the `Promise` constructor).
   #resolve: (t: T) => void;
+  // @ts-expect-error: We do initialize this synchronously (assuming no one has tampered with the `Promise` constructor).
   reject: (e?: Error) => void; // TODO: AbortController?
   promise: Promise<T>;
   constructor() {
-    const { promise, resolve, reject } = Promise.withResolvers<T>();
-    this.promise = promise;
-    this.#resolve = resolve;
-    this.reject = reject;
+    this.promise = new Promise((resolve, reject) => {
+      this.#resolve = resolve;
+      this.reject = reject;
+    });
   }
   handleNewValue(t: T): void {
     this.#resolve(t);

src/cubing/twisty/views/firstElementWithId.ts

@@ -1,26 +1,30 @@
 // Normally we'd capitalize `ID`, but `Id` matches DOM API function names.
 export async function firstElementWithId(id: string): Promise<Element> {
-  const { promise, resolve, reject: _ } = Promise.withResolvers<Element>();
-  const currentElem = document.getElementById(id);
-  if (currentElem) {
-    resolve(currentElem);
-  }
-  const observer = new MutationObserver((mutations: MutationRecord[]) => {
-    for (const mutation of mutations) {
-      if (
-        mutation.attributeName === "id" &&
-        mutation.target instanceof Element &&
-        mutation.target.getAttribute("id") === id
-      ) {
-        resolve(mutation.target);
-        observer.disconnect();
+  return new Promise((resolve, reject) => {
+    try {
+      const currentElem = document.getElementById(id);
+      if (currentElem) {
+        resolve(currentElem);
       }
-    }
-  });
+      const observer = new MutationObserver((mutations: MutationRecord[]) => {
+        for (const mutation of mutations) {
+          if (
+            mutation.attributeName === "id" &&
+            mutation.target instanceof Element &&
+            mutation.target.getAttribute("id") === id
+          ) {
+            resolve(mutation.target);
+            observer.disconnect();
+          }
+        }
+      });
 
-  observer.observe(document.body, {
-    attributeFilter: ["id"],
-    subtree: true,
+      observer.observe(document.body, {
+        attributeFilter: ["id"],
+        subtree: true,
+      });
+    } catch (e) {
+      reject(e);
+    }
   });
-  return promise;
 }