Abstract away or eliminate most of the mutation of the Elements array (#955)

src/data/json.ts

@@ -14,7 +14,7 @@ export function serializeAsJSON(
       type: "excalidraw",
       version: 1,
       source: window.location.origin,
-      elements,
+      elements: elements.filter(element => !element.isDeleted),
       appState: cleanAppStateForExport(appState),
     },
     null,

src/data/localStorage.ts

@@ -10,7 +10,10 @@ export function saveToLocalStorage(
   elements: readonly ExcalidrawElement[],
   appState: AppState,
 ) {
-  localStorage.setItem(LOCAL_STORAGE_KEY, JSON.stringify(elements));
+  localStorage.setItem(
+    LOCAL_STORAGE_KEY,
+    JSON.stringify(elements.filter(element => !element.isDeleted)),
+  );
   localStorage.setItem(
     LOCAL_STORAGE_KEY_STATE,
     JSON.stringify(clearAppStateForLocalStorage(appState)),

src/data/restore.ts

@@ -1,4 +1,4 @@
-import { Point } from "roughjs/bin/geometry";
+import { Point } from "../types";
 
 import { ExcalidrawElement } from "../element/types";
 import { AppState } from "../types";