Reduce stalls when opening large diffs (#4574)

* perf(app): reduce avoidable work when opening large diffs Large snapshots were recursively reconstructed for reference stability, while native scroll worklets captured complete file models. Preserve identity at the data producers and prepare text for the visible window without rebuilding unchanged files. * test(app): await commit diff query completion without polling * chore(app): remove profiling artifacts from the source tree
2026-10-27 11:42:52 +00:00 · 2026-09-09 16:05:44 +02:00
parent 0b3d82a469
commit d311797653
21 changed files with 816 additions and 163 deletions
@@ -0,0 +1,76 @@
+import { QueryClient, QueryObserver } from "@tanstack/react-query";
+import { describe, expect, it } from "vitest";
+import { fetchQueryOptions } from "@/data/query";
+import { commitFileDiffQueryOptions } from "./commit-file-diff-query";
+
+const file = { path: "a.ts", isNew: true, isDeleted: false, additions: 0, deletions: 0, hunks: [] };
+
+describe("commit file diff fetching", () => {
+  it("reuses a cached commit body on remount and fetches on explicit refresh", async () => {
+    const queryClient = new QueryClient();
+    let calls = 0;
+    const options = fetchQueryOptions(
+      commitFileDiffQueryOptions({
+        serverId: "host",
+        cwd: "/repo",
+        sha: "abc",
+        path: "a.ts",
+        enabled: true,
+        client: {
+          async getCommitFileDiff() {
+            calls++;
+            return { file };
+          },
+        },
+      }),
+    );
+    queryClient.setQueryData(
+      options.queryKey,
+      { file },
+      { updatedAt: Date.now() - 24 * 60 * 60 * 1000 },
+    );
+    const observer = new QueryObserver(queryClient, options);
+    const detach = observer.subscribe(() => {});
+    try {
+      await Promise.resolve();
+      expect(calls).toBe(0);
+      expect(observer.getCurrentResult().data?.file).toBe(file);
+      await observer.refetch();
+      expect(calls).toBe(1);
+    } finally {
+      detach();
+      queryClient.clear();
+    }
+  });
+
+  it("retries a cached null result when reopened", async () => {
+    const queryClient = new QueryClient();
+    const options = fetchQueryOptions(
+      commitFileDiffQueryOptions({
+        serverId: "host",
+        cwd: "/repo",
+        sha: "abc",
+        path: "a.ts",
+        enabled: true,
+        client: {
+          async getCommitFileDiff() {
+            return { file };
+          },
+        },
+      }),
+    );
+    queryClient.setQueryData(options.queryKey, { file: null });
+    const observer = new QueryObserver(queryClient, options);
+    const settled = Promise.withResolvers<void>();
+    const detach = observer.subscribe((result) => {
+      if (result.fetchStatus === "idle") settled.resolve();
+    });
+    try {
+      await settled.promise;
+      expect(observer.getCurrentResult().data?.file).toEqual(file);
+    } finally {
+      detach();
+      queryClient.clear();
+    }
+  });
+});