refactor(git): extract _create_commit_cmd_string, better test coverage

commitizen/git.py

@@ -181,19 +181,22 @@ def commit(
     f.write(message.encode("utf-8"))
     f.close()
 
-    command = f'git commit {args} -F "{f.name}"'
-
-    if committer_date and os.name == "nt":  # pragma: no cover
-        # Using `cmd /v /c "{command}"` sets environment variables only for that command
-        command = f'cmd /v /c "set GIT_COMMITTER_DATE={committer_date}&& {command}"'
-    elif committer_date:
-        command = f"GIT_COMMITTER_DATE={committer_date} {command}"
-
+    command = _create_commit_cmd_string(args, committer_date, f.name)
     c = cmd.run(command)
     os.unlink(f.name)
     return c
 
 
+def _create_commit_cmd_string(args: str, committer_date: str | None, name: str) -> str:
+    command = f'git commit {args} -F "{name}"'
+    if not committer_date:
+        return command
+    if os.name != "nt":
+        return f"GIT_COMMITTER_DATE={committer_date} {command}"
+    # Using `cmd /v /c "{command}"` sets environment variables only for that command
+    return f'cmd /v /c "set GIT_COMMITTER_DATE={committer_date}&& {command}"'
+
+
 def get_commits(
     start: str | None = None,
     end: str = "HEAD",

tests/test_git.py

@@ -449,3 +449,27 @@ def test_git_commit_from_rev_and_commit():
     assert commit.author == "John Doe"
     assert commit.author_email == "john@example.com"
     assert commit.parents == []
+
+
+@pytest.mark.parametrize(
+    "os_name,committer_date,expected_cmd",
+    [
+        (
+            "nt",
+            "2024-03-20",
+            'cmd /v /c "set GIT_COMMITTER_DATE=2024-03-20&& git commit  -F "temp.txt""',
+        ),
+        (
+            "posix",
+            "2024-03-20",
+            'GIT_COMMITTER_DATE=2024-03-20 git commit  -F "temp.txt"',
+        ),
+        ("nt", None, 'git commit  -F "temp.txt"'),
+        ("posix", None, 'git commit  -F "temp.txt"'),
+    ],
+)
+def test_create_commit_cmd_string(mocker, os_name, committer_date, expected_cmd):
+    """Test the OS-specific behavior of _create_commit_cmd_string"""
+    mocker.patch("os.name", os_name)
+    result = git._create_commit_cmd_string("", committer_date, "temp.txt")
+    assert result == expected_cmd