fs: auto-close Dir async iterator on exit

src/js/node/fs.ts

@@ -1126,12 +1126,20 @@ class Dir {
   }
 
   async *[Symbol.asyncIterator]() {
-    let entries = (this.#entries ??= (await fs.readdir(this.#path, {
-      withFileTypes: true,
-      encoding: this.#options?.encoding,
-      recursive: this.#options?.recursive,
-    })) as DirentType[]);
-    yield* entries;
+    try {
+      let entries = (this.#entries ??= (await fs.readdir(this.#path, {
+        withFileTypes: true,
+        encoding: this.#options?.encoding,
+        recursive: this.#options?.recursive,
+      })) as DirentType[]);
+      yield* entries;
+    } finally {
+      // The user may have closed the directory already. Swallow ERR_DIR_CLOSED
+      // to match Node's behavior (see lib/internal/fs/dir.js).
+      try {
+        this.closeSync();
+      } catch {}
+    }
   }
 }
 

test/regression/issue/28894.test.ts

@@ -0,0 +1,75 @@
+// https://github.com/oven-sh/bun/issues/28894
+// `fs.Dir` async iterator should close the directory handle on exit
+// (natural completion, `break`, or thrown error) to match Node.js.
+import { expect, test } from "bun:test";
+import { tempDir } from "harness";
+import { opendir as opendirPromise } from "node:fs/promises";
+
+test("Dir async iterator closes handle on break", async () => {
+  using dir = tempDir("dir-iter-break", {
+    "a.txt": "",
+    "b.txt": "",
+    "c.txt": "",
+  });
+  const d = await opendirPromise(String(dir));
+
+  const names: string[] = [];
+  for await (const entry of d) {
+    names.push(entry.name);
+    break;
+  }
+  expect(names).toHaveLength(1);
+
+  // The iterator should have closed the handle. A second close must throw.
+  expect(() => d.closeSync()).toThrow("Directory handle was closed");
+});
+
+test("Dir async iterator closes handle on natural completion", async () => {
+  using dir = tempDir("dir-iter-complete", {
+    "x.txt": "",
+    "y.txt": "",
+  });
+  const d = await opendirPromise(String(dir));
+
+  const names: string[] = [];
+  for await (const entry of d) {
+    names.push(entry.name);
+  }
+  expect(names.sort()).toEqual(["x.txt", "y.txt"]);
+
+  expect(() => d.closeSync()).toThrow("Directory handle was closed");
+});
+
+test("Dir async iterator closes handle when body throws", async () => {
+  using dir = tempDir("dir-iter-throw", {
+    "a.txt": "",
+    "b.txt": "",
+  });
+  const d = await opendirPromise(String(dir));
+
+  await expect(
+    (async () => {
+      for await (const _entry of d) {
+        throw new Error("boom");
+      }
+    })(),
+  ).rejects.toThrow("boom");
+
+  expect(() => d.closeSync()).toThrow("Directory handle was closed");
+});
+
+test("Dir async iterator swallows ERR_DIR_CLOSED when user closed manually", async () => {
+  using dir = tempDir("dir-iter-user-closed", {
+    "a.txt": "",
+  });
+  const d = await opendirPromise(String(dir));
+
+  // Iterator must not throw even if user already closed inside the loop.
+  for await (const _entry of d) {
+    d.closeSync();
+    break;
+  }
+
+  // Still closed; second close throws.
+  expect(() => d.closeSync()).toThrow("Directory handle was closed");
+});