clan-cli: add git.commit_file() to auto commit files if inside a git

- commit only if inside a git repo
- commit only the specified file and nothing else
- auto-generate commit message if not specified

pkgs/clan-cli/tests/conftest.py

@@ -1,5 +1,11 @@
 import os
+import subprocess
 import sys
+from pathlib import Path
+
+import pytest
+
+from clan_cli.nix import nix_shell
 
 sys.path.append(os.path.join(os.path.dirname(__file__), "helpers"))
 
@@ -14,3 +20,18 @@ pytest_plugins = [
     "host_group",
     "test_flake",
 ]
+
+
+# fixture for git_repo
+@pytest.fixture
+def git_repo(tmp_path: Path) -> Path:
+    # initialize a git repository
+    cmd = nix_shell(["git"], ["git", "init"])
+    subprocess.run(cmd, cwd=tmp_path, check=True)
+    # set user.name and user.email
+    cmd = nix_shell(["git"], ["git", "config", "user.name", "test"])
+    subprocess.run(cmd, cwd=tmp_path, check=True)
+    cmd = nix_shell(["git"], ["git", "config", "user.email", "test@test.test"])
+    subprocess.run(cmd, cwd=tmp_path, check=True)
+    # return the path to the git repository
+    return tmp_path