Jesus sucks

backend/frontend/node_modules/@restart/hooks/esm/useMap.js

@@ -0,0 +1,52 @@
+import useForceUpdate from './useForceUpdate';
+import useStableMemo from './useStableMemo';
+export class ObservableMap extends Map {
+  constructor(listener, init) {
+    super(init);
+    this.listener = listener;
+  }
+  set(key, value) {
+    super.set(key, value);
+    // When initializing the Map, the base Map calls this.set() before the
+    // listener is assigned so it will be undefined
+    if (this.listener) this.listener(this);
+    return this;
+  }
+  delete(key) {
+    let result = super.delete(key);
+    this.listener(this);
+    return result;
+  }
+  clear() {
+    super.clear();
+    this.listener(this);
+  }
+}
+
+/**
+ * Create and return a [Map](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map) that triggers rerenders when it's updated.
+ *
+ * ```tsx
+ * const customerAges = useMap<number>([
+ *  ['john', 24],
+ *  ['betsy', 25]
+ * ]);
+ *
+ * return (
+ *  <>
+ *    {Array.from(ids, ([name, age]) => (
+ *      <div>
+ *        {name}: {age}. <button onClick={() => ids.delete(name)}>X</button>
+ *      </div>
+ *    )}
+ *  </>
+ * )
+ * ```
+ *
+ * @param init initial Map entries
+ */
+function useMap(init) {
+  const forceUpdate = useForceUpdate();
+  return useStableMemo(() => new ObservableMap(forceUpdate, init), []);
+}
+export default useMap;