Fix issue with creating .gitignore with venvs (#24155)

Fixes #24151

python_files/create_venv.py

@@ -78,6 +78,10 @@ def file_exists(path: Union[str, pathlib.PurePath]) -> bool:
     return pathlib.Path(path).exists()
 
 
+def is_file(path: Union[str, pathlib.PurePath]) -> bool:
+    return pathlib.Path(path).is_file()
+
+
 def venv_exists(name: str) -> bool:
     return (
         (CWD / name).exists()
@@ -134,11 +138,15 @@ def upgrade_pip(venv_path: str) -> None:
     print("CREATE_VENV.UPGRADED_PIP")
 
 
+def create_gitignore(git_ignore: Union[str, pathlib.PurePath]):
+    print("Creating:", os.fspath(git_ignore))
+    pathlib.Path(git_ignore).write_text("*")
+
+
 def add_gitignore(name: str) -> None:
     git_ignore = CWD / name / ".gitignore"
-    if git_ignore.is_file():
-        print("Creating:", os.fspath(git_ignore))
-        git_ignore.write_text("*")
+    if not is_file(git_ignore):
+        create_gitignore(git_ignore)
 
 
 def download_pip_pyz(name: str):

python_files/tests/test_create_venv.py

@@ -51,13 +51,14 @@ def test_venv_not_installed_windows():
 
 
 @pytest.mark.parametrize("env_exists", ["hasEnv", "noEnv"])
-@pytest.mark.parametrize("git_ignore", ["useGitIgnore", "skipGitIgnore"])
+@pytest.mark.parametrize("git_ignore", ["useGitIgnore", "skipGitIgnore", "gitIgnoreExists"])
 @pytest.mark.parametrize("install", ["requirements", "toml", "skipInstall"])
 def test_create_env(env_exists, git_ignore, install):
     importlib.reload(create_venv)
     create_venv.is_installed = lambda _x: True
     create_venv.venv_exists = lambda _n: env_exists == "hasEnv"
     create_venv.upgrade_pip = lambda _x: None
+    create_venv.is_file = lambda _x: git_ignore == "gitIgnoreExists"
 
     install_packages_called = False
 
@@ -84,9 +85,19 @@ def run_process(args, error_message):
     def add_gitignore(_name):
         nonlocal add_gitignore_called
         add_gitignore_called = True
+        if not create_venv.is_file(_name):
+            create_venv.create_gitignore(_name)
 
     create_venv.add_gitignore = add_gitignore
 
+    create_gitignore_called = False
+
+    def create_gitignore(_p):
+        nonlocal create_gitignore_called
+        create_gitignore_called = True
+
+    create_venv.create_gitignore = create_gitignore
+
     args = []
     if git_ignore == "useGitIgnore":
         args += ["--git-ignore"]
@@ -104,6 +115,8 @@ def add_gitignore(_name):
     # add_gitignore is called when new venv is created and git_ignore is True
     assert add_gitignore_called == ((env_exists == "noEnv") and (git_ignore == "useGitIgnore"))
 
+    assert create_gitignore_called == (add_gitignore_called and (git_ignore != "gitIgnoreExists"))
+
 
 @pytest.mark.parametrize("install_type", ["requirements", "pyproject", "both"])
 def test_install_packages(install_type):