refactor: decoupling global Scene state part-1 (#7577)

packages/excalidraw/utils.ts

@@ -650,8 +650,11 @@ export const getUpdatedTimestamp = () => (isTestEnv() ? 1 : Date.now());
  * or array of ids (strings), into a Map, keyd by `id`.
  */
 export const arrayToMap = <T extends { id: string } | string>(
-  items: readonly T[],
+  items: readonly T[] | Map<string, T>,
 ) => {
+  if (items instanceof Map) {
+    return items;
+  }
   return items.reduce((acc: Map<string, T>, element) => {
     acc.set(typeof element === "string" ? element : element.id, element);
     return acc;
@@ -1050,3 +1053,40 @@ export function getSvgPathFromStroke(points: number[][], closed = true) {
 export const normalizeEOL = (str: string) => {
   return str.replace(/\r?\n|\r/g, "\n");
 };
+
+// -----------------------------------------------------------------------------
+type HasBrand<T> = {
+  // eslint-disable-next-line @typescript-eslint/no-unused-vars
+  [K in keyof T]: K extends `~brand${infer _}` ? true : never;
+}[keyof T];
+
+type RemoveAllBrands<T> = HasBrand<T> extends true
+  ? {
+      // eslint-disable-next-line @typescript-eslint/no-unused-vars
+      [K in keyof T as K extends `~brand~${infer _}` ? never : K]: T[K];
+    }
+  : never;
+
+// adapted from https://github.com/colinhacks/zod/discussions/1994#discussioncomment-6068940
+// currently does not cover all types (e.g. tuples, promises...)
+type Unbrand<T> = T extends Map<infer E, infer F>
+  ? Map<E, F>
+  : T extends Set<infer E>
+  ? Set<E>
+  : T extends Array<infer E>
+  ? Array<E>
+  : RemoveAllBrands<T>;
+
+/**
+ * Makes type into a branded type, ensuring that value is assignable to
+ * the base ubranded type. Optionally you can explicitly supply current value
+ * type to combine both (useful for composite branded types. Make sure you
+ * compose branded types which are not composite themselves.)
+ */
+export const toBrandedType = <BrandedType, CurrentType = BrandedType>(
+  value: Unbrand<BrandedType>,
+) => {
+  return value as CurrentType & BrandedType;
+};
+
+// -----------------------------------------------------------------------------