Add unit tests for filetree lookup exclude handling

tests/unit/plugins/lookup/test_filetree.py

@@ -0,0 +1,81 @@
+# Copyright (c) 2026, Ansible Project
+# GNU General Public License v3.0+ (see LICENSES/GPL-3.0-or-later.txt or https://www.gnu.org/licenses/gpl-3.0.txt)
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+from __future__ import annotations
+
+import os
+import shutil
+import tempfile
+import unittest
+from unittest.mock import patch
+
+from ansible.errors import AnsibleLookupError
+from ansible.plugins.loader import lookup_loader
+from ansible.template import Templar
+
+from ansible_collections.community.internal_test_tools.tests.unit.mock.loader import DictDataLoader
+
+
+class TestFiletreeLookup(unittest.TestCase):
+    def setUp(self):
+        self.loader = DictDataLoader({})
+        self.templar = Templar(loader=self.loader, variables={})
+        self.lookup = lookup_loader.get(
+            "community.general.filetree",
+            loader=self.loader,
+            templar=self.templar,
+        )
+        self.tmpdir = tempfile.mkdtemp(prefix="ansible_test_filetree_")
+        self.tree_root = os.path.join(self.tmpdir, "data")
+        os.makedirs(os.path.join(self.tree_root, ".git"))
+        os.makedirs(os.path.join(self.tree_root, "subdir"))
+        with open(os.path.join(self.tree_root, "app.conf"), "w", encoding="utf-8") as handle:
+            handle.write("content\n")
+        with open(os.path.join(self.tree_root, "subdir", "nested.conf"), "w", encoding="utf-8") as handle:
+            handle.write("nested\n")
+
+    def tearDown(self):
+        shutil.rmtree(self.tmpdir)
+
+    def _run_lookup(self, **kwargs):
+        with (
+            patch.object(self.lookup, "get_basedir", return_value=self.tmpdir),
+            patch.object(self.loader, "path_dwim_relative", return_value=self.tmpdir),
+        ):
+            return self.lookup.run(["data"], {}, **kwargs)
+
+    def test_invalid_exclude_regex_raises_lookup_error(self):
+        with self.assertRaises(AnsibleLookupError) as ctx:
+            self._run_lookup(exclude="temp[1")
+
+        self.assertIn("Invalid exclude regular expression", str(ctx.exception))
+        self.assertIn("temp[1", str(ctx.exception))
+
+    def test_valid_exclude_skips_matching_basenames(self):
+        result = self._run_lookup(exclude=r"^\.git$")
+
+        paths = {entry["path"] for entry in result}
+        self.assertIn("app.conf", paths)
+        self.assertIn(os.path.join("subdir", "nested.conf"), paths)
+        self.assertNotIn(".git", paths)
+
+    def test_lookup_without_exclude_lists_entries(self):
+        result = self._run_lookup()
+
+        paths = {entry["path"] for entry in result}
+        self.assertIn("app.conf", paths)
+        self.assertIn(".git", paths)
+        self.assertIn("subdir", paths)
+        self.assertIn(os.path.join("subdir", "nested.conf"), paths)
+
+    def test_file_entry_includes_expected_properties(self):
+        result = self._run_lookup()
+        app_conf = next(entry for entry in result if entry["path"] == "app.conf")
+
+        self.assertEqual(app_conf["state"], "file")
+        self.assertEqual(app_conf["root"], self.tree_root)
+        self.assertEqual(app_conf["src"], os.path.join(self.tree_root, "app.conf"))
+        self.assertIn("mode", app_conf)
+        self.assertIn("owner", app_conf)
+        self.assertIn("group", app_conf)