fix(cli): apply index updates in place instead of fetching the whole index

The interactive mode fetched and re-parsed the full index on every
index_delta, on the loop receiving the download: 67 times in 80 s while
a node enriched a library.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

1 files changed, 43 insertions, 0 deletions

diff --git a/packages/meshbay-cli/tests/test_interactive.py b/packages/meshbay-cli/tests/test_interactive.py
index 36b7f47..9960533 100644
--- a/packages/meshbay-cli/tests/test_interactive.py
+++ b/packages/meshbay-cli/tests/test_interactive.py
@@ -444,3 +444,46 @@ async def test_put_sends_a_file_into_the_chat_folder_and_get_saves_one_here(
         await say("/get ../share/x")
         await _until(pilot, lambda: "name a file of the chat's folder" in _said(room))
         await pilot.press("escape")
+
+
+async def test_index_updates_are_applied_not_asked_for_again(world, monkeypatch):
+    """
+    A library being enriched pushes an `index_delta` about once a second, each
+    one filling in a file's fields. The panes used to answer every one with the
+    whole index — 67 full indexes in the 80 s of one download on a real node,
+    on the event loop the download was being received on. Updates are applied
+    where they land; only a delta that adds or removes a file asks again, once
+    for a burst.
+    """
+    from meshbay_cli.tui import screens
+    monkeypatch.setattr(screens, "REFRESH_AFTER_DELTA_S", 0.2)
+    hub, node, work = world
+    film = node.add("share", "film.mkv", b"F" * 5000)
+    assert await asyncio.to_thread(cli.main, ["--hub", "https://hub.test", "-u", USERNAME,
+                                              "--password", PASSPHRASE, "login"]) == 0
+    app = _app()
+    async with app.run_test(size=(140, 40)) as pilot:
+        await _until(pilot, lambda: isinstance(app.screen, MainScreen))
+        remote = app.screen.query_one(RemotePane)
+        await _open(pilot, remote, f"Family@{USERNAME}/")
+        await _open(pilot, remote, "share/")
+        await _until(pilot, lambda: "film.mkv" in _names(remote))
+        asked = node.index_syncs
+
+        for i in range(20):
+            node.push_delta(updates=[{**film, "duration": 100 + i}])
+        await pilot.pause(0.6)
+        assert node.index_syncs == asked, "an update must not fetch the whole index"
+        tree = app.screen._trees["g1"]
+        assert tree.file("share/film.mkv")["duration"] == 119
+
+        extra = [node.add("share", f"new{i}.txt", b"n%d" % i) for i in range(3)]
+        node.files = {k: v for k, v in node.files.items() if v not in extra}
+        for e in extra:
+            node.push_delta(additions=[e])
+        await _until(pilot, lambda: "new2.txt" in _names(remote))
+        await pilot.pause(0.6)
+        assert node.index_syncs == asked + 1, "a burst of additions asks again once"
+
+        node.push_delta(deletions=[film["id"]])
+        await _until(pilot, lambda: "film.mkv" not in _names(remote))