Restore editor history after reload

src/frontend/utils/circuit-editor-history.ts

@@ -0,0 +1,27 @@
+import type {
+  CircuitTreeResponseDto,
+  ProjectHistoryStateDto,
+} from "../types";
+
+export interface CircuitEditorSnapshot {
+  tree: CircuitTreeResponseDto;
+  history: ProjectHistoryStateDto;
+}
+
+export async function loadCircuitEditorSnapshot(
+  readTree: () => Promise<CircuitTreeResponseDto>,
+  readHistory: () => Promise<ProjectHistoryStateDto>,
+  maxAttempts = 3
+): Promise<CircuitEditorSnapshot> {
+  for (let attempt = 0; attempt < maxAttempts; attempt += 1) {
+    const tree = await readTree();
+    const history = await readHistory();
+    if (tree.currentRevision === history.currentRevision) {
+      return { tree, history };
+    }
+  }
+
+  throw new Error(
+    "Der Projektstand hat sich während des Ladens geändert. Bitte erneut versuchen."
+  );
+}