fix(file-observer): track files announced by native change events

packages/server/src/server/file-observer/internal/native-recursive.test.ts

@@ -9,66 +9,75 @@ import { createObserverPaths } from "./paths.js";
 
 // Native watchers may coalesce file removals into change notifications. Keep the
 // filesystem real while controlling which notifications reach reconciliation.
-test("shallow parent scans retain nested change scopes", async () => {
-  const root = await mkdtemp(join(tmpdir(), "native-scopes-"));
-  const paths = createObserverPaths(process.platform);
-  const removed = [
-    join(root, "root.txt"),
-    join(root, "child", "child.txt"),
-    join(root, "child", "deep", "deep.txt"),
-  ];
-  await mkdir(join(root, "child", "deep"), { recursive: true });
-  await Promise.all(removed.map((path) => writeFile(path, "before")));
-  const events: FileChange[] = [];
-  const notifications = new EventEmitter();
-  let active = true;
-  const observer = createFileObserver();
-  const backend = createNativeRecursiveBackend(
-    {
-      root,
-      metrics: observer.getDiagnostics(),
-      isActive: () => active,
-      isIgnored: () => false,
-      isPathInside: paths.isInside,
-      queueEvent: (type, path) => events.push({ type, path }),
-      fail: (error) => {
-        throw error;
-      },
-    },
-    paths,
-    (_root, listener) => {
-      notifications.on("change", listener);
-      return {
-        close: () => {
-          notifications.removeAllListeners();
+test.each(["existing", "new"])(
+  "shallow scans recover coalesced deletes of %s files in nested scopes",
+  async (population) => {
+    const root = await mkdtemp(join(tmpdir(), "native-scopes-"));
+    const paths = createObserverPaths(process.platform);
+    const removed = [
+      join(root, "root.txt"),
+      join(root, "child", "child.txt"),
+      join(root, "child", "deep", "deep.txt"),
+    ];
+    await mkdir(join(root, "child", "deep"), { recursive: true });
+    if (population === "existing") {
+      await Promise.all(removed.map((path) => writeFile(path, "before")));
+    }
+    const events: FileChange[] = [];
+    const notifications = new EventEmitter();
+    let active = true;
+    const observer = createFileObserver();
+    const backend = createNativeRecursiveBackend(
+      {
+        root,
+        metrics: observer.getDiagnostics(),
+        isActive: () => active,
+        isIgnored: () => false,
+        isPathInside: paths.isInside,
+        queueEvent: (type, path) => events.push({ type, path }),
+        fail: (error) => {
+          throw error;
         },
-        on: (event, onError) => notifications.on(event, onError),
-      };
-    },
-  );
-  try {
-    await backend.start();
-    await Promise.all(removed.map((path) => rm(path)));
-    vi.useFakeTimers({ toFake: ["setTimeout", "clearTimeout", "performance"] });
-    for (const path of removed) notifications.emit("change", "change", path);
-    await vi.advanceTimersByTimeAsync(8_000);
-    vi.useRealTimers();
-    await expect
-      .poll(() =>
-        events
-          .filter((event) => event.type === "delete")
-          .map((event) => event.path)
-          .sort(),
-      )
-      .toEqual([...removed].sort());
-  } finally {
-    vi.useRealTimers();
-    active = false;
-    await backend.close();
-    await observer.close();
-    await rm(root, { recursive: true, force: true });
-  }
-});
+      },
+      paths,
+      (_root, listener) => {
+        notifications.on("change", listener);
+        return {
+          close: () => {
+            notifications.removeAllListeners();
+          },
+          on: (event, onError) => notifications.on(event, onError),
+        };
+      },
+    );
+    try {
+      await backend.start();
+      if (population === "new") {
+        await Promise.all(removed.map((path) => writeFile(path, "before")));
+        for (const path of removed) notifications.emit("change", "change", path);
+      }
+      await Promise.all(removed.map((path) => rm(path)));
+      vi.useFakeTimers({ toFake: ["setTimeout", "clearTimeout", "performance"] });
+      for (const path of removed) notifications.emit("change", "change", path);
+      await vi.advanceTimersByTimeAsync(8_000);
+      vi.useRealTimers();
+      await expect
+        .poll(() =>
+          events
+            .filter((event) => event.type === "delete")
+            .map((event) => event.path)
+            .sort(),
+        )
+        .toEqual([...removed].sort());
+    } finally {
+      vi.useRealTimers();
+      active = false;
+      await backend.close();
+      await observer.close();
+      await rm(root, { recursive: true, force: true });
+    }
+  },
+);
 
 test("a file announced only as changed remains visible to coalesced deletion scans", async () => {
   const root = await mkdtemp(join(tmpdir(), "native-change-only-"));