fix lefthook (#17023)

test/unit_test/tools/test_check_files.py

@@ -0,0 +1,31 @@
+from pathlib import Path
+from subprocess import CompletedProcess
+
+from tools.hooks import check_files
+
+
+def test_staged_paths_preserve_whitespace(monkeypatch):
+    paths = b"space name.py\0line\nbreak.go\0"
+
+    def run(command, **kwargs):
+        assert command == ["git", "diff", "--cached", "--name-only", "--diff-filter=ACMR", "-z"]
+        assert kwargs == {"check": True, "capture_output": True}
+        return CompletedProcess(command, 0, stdout=paths)
+
+    monkeypatch.setattr(check_files.subprocess, "run", run)
+
+    assert check_files._staged_paths() == [Path("space name.py"), Path("line\nbreak.go")]
+
+
+def test_case_conflicts_preserve_newlines(monkeypatch, capsys):
+    paths = b"dir/A\nfile.py\0dir/a\nfile.py\0"
+
+    def run(command, **kwargs):
+        assert command == ["git", "ls-files", "-z"]
+        assert kwargs == {"check": True, "capture_output": True}
+        return CompletedProcess(command, 0, stdout=paths)
+
+    monkeypatch.setattr(check_files.subprocess, "run", run)
+
+    assert check_files.check_case_conflicts([]) == 1
+    assert "case conflict:" in capsys.readouterr().err