remove closures from mutateElement, get rid of the element spreading (#902)

src/element/mutateElement.ts

@@ -1,26 +1,42 @@
-import {
-  MutableExcalidrawElement,
-  MutableExcalidrawTextElement,
-} from "./types";
+import { ExcalidrawElement, ExcalidrawTextElement } from "./types";
+
+type ElementUpdate<TElement extends ExcalidrawElement> = Omit<
+  Partial<TElement>,
+  "id" | "seed"
+>;
 
 // This function tracks updates of text elements for the purposes for collaboration.
 // The version is used to compare updates when more than one user is working in
 // the same drawing.
 export function mutateElement(
-  element: MutableExcalidrawElement,
-  callback: (mutatableElement: MutableExcalidrawElement) => void,
-): void {
-  element.version++;
-  callback(element);
+  element: ExcalidrawElement,
+  updates: ElementUpdate<ExcalidrawElement>,
+) {
+  Object.assign(element, updates);
+  (element as any).version++;
+}
+
+export function newElementWith(
+  element: ExcalidrawElement,
+  updates: ElementUpdate<ExcalidrawElement>,
+): ExcalidrawElement {
+  return { ...element, ...updates, version: element.version + 1 };
 }
 
 // This function tracks updates of text elements for the purposes for collaboration.
 // The version is used to compare updates when more than one user is working in
 // the same document.
 export function mutateTextElement(
-  element: MutableExcalidrawTextElement,
-  callback: (mutatableElement: MutableExcalidrawTextElement) => void,
+  element: ExcalidrawTextElement,
+  updates: ElementUpdate<ExcalidrawTextElement>,
 ): void {
-  element.version++;
-  callback(element);
+  Object.assign(element, updates);
+  (element as any).version++;
+}
+
+export function newTextElementWith(
+  element: ExcalidrawTextElement,
+  updates: ElementUpdate<ExcalidrawTextElement>,
+): ExcalidrawTextElement {
+  return { ...element, ...updates, version: element.version + 1 };
 }