auto-git:

[add] .prettierrc.json
 [add] eslint.config.js
 [add] index.html
 [add] package.json
 [add] playwright.config.ts
 [add] src/app/App.tsx
 [add] src/app/app.css
 [add] src/app/editor-store.ts
 [add] src/app/use-editor-store.ts
 [add] src/assets/.gitkeep
 [add] src/commands/command-history.ts
 [add] src/commands/command.ts
 [add] src/commands/set-scene-name-command.ts
 [add] src/core/ids.ts
 [add] src/core/selection.ts
 [add] src/core/tool-mode.ts
 [add] src/core/vector.ts
 [add] src/document/migrate-scene-document.ts
 [add] src/document/scene-document.ts
 [add] src/entities/.gitkeep
 [add] src/geometry/.gitkeep
 [add] src/main.tsx
 [add] src/materials/.gitkeep
 [add] src/runtime-three/.gitkeep
 [add] src/serialization/local-draft-storage.ts
 [add] src/serialization/scene-document-json.ts
 [add] src/shared-ui/Panel.tsx
 [add] src/viewport-three/ViewportCanvas.tsx
 [add] src/viewport-three/viewport-host.ts
 [add] src/vite-env.d.ts
 [add] tests/domain/create-empty-scene-document.test.ts
 [add] tests/domain/editor-store.test.ts
 [add] tests/e2e/app-smoke.e2e.ts
 [add] tests/serialization/scene-document-json.test.ts
 [add] tests/setup/vitest.setup.ts
 [add] tsconfig.json
 [add] vite.config.ts
 [add] vitest.config.ts

src/serialization/local-draft-storage.ts

@@ -0,0 +1,45 @@
+import { createEmptySceneDocument, type SceneDocument } from "../document/scene-document";
+
+import { parseSceneDocumentJson, serializeSceneDocument } from "./scene-document-json";
+
+export interface KeyValueStorage {
+  getItem(key: string): string | null;
+  setItem(key: string, value: string): void;
+  removeItem(key: string): void;
+}
+
+export const DEFAULT_SCENE_DRAFT_STORAGE_KEY = "webeditor3d.scene-document-draft";
+
+export function getBrowserStorage(): KeyValueStorage | null {
+  if (typeof window === "undefined") {
+    return null;
+  }
+
+  return window.localStorage;
+}
+
+export function saveSceneDocumentDraft(
+  storage: KeyValueStorage,
+  document: SceneDocument,
+  key = DEFAULT_SCENE_DRAFT_STORAGE_KEY
+) {
+  storage.setItem(key, serializeSceneDocument(document));
+}
+
+export function loadSceneDocumentDraft(storage: KeyValueStorage, key = DEFAULT_SCENE_DRAFT_STORAGE_KEY): SceneDocument | null {
+  const rawDocument = storage.getItem(key);
+
+  if (rawDocument === null) {
+    return null;
+  }
+
+  return parseSceneDocumentJson(rawDocument);
+}
+
+export function loadOrCreateSceneDocument(storage: KeyValueStorage | null, key = DEFAULT_SCENE_DRAFT_STORAGE_KEY): SceneDocument {
+  if (storage === null) {
+    return createEmptySceneDocument();
+  }
+
+  return loadSceneDocumentDraft(storage, key) ?? createEmptySceneDocument();
+}

src/serialization/scene-document-json.ts

@@ -0,0 +1,19 @@
+import type { SceneDocument } from "../document/scene-document";
+import { migrateSceneDocument } from "../document/migrate-scene-document";
+
+export function serializeSceneDocument(document: SceneDocument): string {
+  return JSON.stringify(document, null, 2);
+}
+
+export function parseSceneDocumentJson(source: string): SceneDocument {
+  let parsedValue: unknown;
+
+  try {
+    parsedValue = JSON.parse(source);
+  } catch (error) {
+    const cause = error instanceof Error ? error.message : "Unknown JSON parse failure.";
+    throw new Error(`Scene document JSON could not be parsed: ${cause}`);
+  }
+
+  return migrateSceneDocument(parsedValue);
+}