From 17ba51697dd277a177cfc49e8108b6591d88d699 Mon Sep 17 00:00:00 2001
From: Dave Pearson <davep@davep.org>
Date: Mon, 26 Feb 2024 09:31:30 +0000
Subject: [PATCH 1/2] Fix DirectoryTree.path no longer reacting to new values

Fixes #4208
---
 CHANGELOG.md                           | 1 +
 src/textual/widgets/_directory_tree.py | 1 +
 2 files changed, 2 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index a3534132aa..2df2b1993d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -13,6 +13,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 - Fixed `Sparkline` not working with data in a `deque` https://github.com/Textualize/textual/issues/3899
 - Tooltips are now cleared when the related widget is no longer under them https://github.com/Textualize/textual/issues/3045
 - Simplified tree-sitter highlight queries for HTML, which also seems to fix segfault issue https://github.com/Textualize/textual/pull/4195
+- Fixed `DirectoryTree.path` no longer reacting to new values https://github.com/Textualize/textual/issues/4208
 
 ## [0.52.1] - 2024-02-20
 
diff --git a/src/textual/widgets/_directory_tree.py b/src/textual/widgets/_directory_tree.py
index fbddcb75d9..16f9d0a100 100644
--- a/src/textual/widgets/_directory_tree.py
+++ b/src/textual/widgets/_directory_tree.py
@@ -332,6 +332,7 @@ async def watch_path(self) -> None:
         If the path is changed the directory tree will be repopulated using
         the new value as the root.
         """
+        self.reset_node(self.root, str(self.path), DirEntry(self.PATH(self.path)))
         await self.reload()
 
     def process_label(self, label: TextType) -> Text:

From a9c51612e713e540325f7c129438d10edc3b24e4 Mon Sep 17 00:00:00 2001
From: Dave Pearson <davep@davep.org>
Date: Mon, 26 Feb 2024 10:01:41 +0000
Subject: [PATCH 2/2] Add a unit test for changing DirecotryTree.path

---
 tests/directory_tree/test_change_path.py | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)
 create mode 100644 tests/directory_tree/test_change_path.py

diff --git a/tests/directory_tree/test_change_path.py b/tests/directory_tree/test_change_path.py
new file mode 100644
index 0000000000..1b73f3c09d
--- /dev/null
+++ b/tests/directory_tree/test_change_path.py
@@ -0,0 +1,20 @@
+from pathlib import Path
+
+from textual.app import App, ComposeResult
+from textual.widgets import DirectoryTree
+
+
+class DirectoryTreeApp(App[None]):
+
+    def compose(self) -> ComposeResult:
+        yield DirectoryTree(".")
+
+
+async def test_change_directory_tree_path(tmpdir: Path) -> None:
+    """The DirectoryTree should react to the path changing."""
+
+    async with DirectoryTreeApp().run_test() as pilot:
+        assert pilot.app.query_one(DirectoryTree).root.data.path == Path(".")
+        pilot.app.query_one(DirectoryTree).path = tmpdir
+        await pilot.pause()
+        assert pilot.app.query_one(DirectoryTree).root.data.path == tmpdir