isolate git config in tests (#449)

Author: skshetry

.github/workflows/check-test-release.yml

@@ -41,14 +41,7 @@ jobs:
 
     - run: pip install .[dev]
     - uses: pre-commit/[email protected]
-    - name: Run tests
-      run: |
-        git config --global user.email "[email protected]"
-        git config --global user.name "Olivaw"
-        pytest
-      env:
-        GITHUB_MATRIX_OS: ${{ matrix.os }}
-        GITHUB_MATRIX_PYTHON: ${{ matrix.python }}
+    - run: pytest
 
     - name: "Upload coverage to Codecov"
       uses: codecov/codecov-action@v4

pyproject.toml

@@ -40,6 +40,7 @@ Source = "https://github.com/iterative/gto"
 [project.optional-dependencies]
 tests = [
     "freezegun",
+    "pygit2",
     "pytest",
     "pytest-cov",
     "pytest-mock",
@@ -104,7 +105,7 @@ extend-select = ["I", "B", "C4", "C90", "T10", "Q"]
 known-first-party = ["gto", "tests"]
 
 [tool.pylint.master]
-extension-pkg-whitelist = ["pydantic", "pytest-lazy-fixture", "pytest"]
+extension-pkg-whitelist = ["pydantic", "pytest-lazy-fixture", "pygit2", "pytest"]
 load-plugins= ["pylint.extensions.no_self_use"]
 
 [tool.pylint.message_control]

tests/conftest.py

@@ -1,8 +1,10 @@
 # pylint: disable=redefined-outer-name
+import os
 import sys
 from time import sleep
-from typing import Tuple
+from typing import Iterator, Tuple
 
+import pygit2
 import pytest
 from click.testing import Result
 from pytest_test_utils import TmpDir
@@ -27,6 +29,34 @@ def runner() -> Runner:
     return Runner()
 
 
+@pytest.fixture(scope="session", autouse=True)
+def isolate(tmp_path_factory: pytest.TempPathFactory) -> Iterator[None]:
+    path = tmp_path_factory.mktemp("mock")
+    home_dir = path / "home"
+    home_dir.mkdir()
+
+    monkeypatch = pytest.MonkeyPatch()
+    if sys.platform == "win32":
+        home_drive, home_path = os.path.splitdrive(home_dir)
+        monkeypatch.setenv("USERPROFILE", str(home_dir))
+        monkeypatch.setenv("HOMEDRIVE", home_drive)
+        monkeypatch.setenv("HOMEPATH", home_path)
+    else:
+        monkeypatch.setenv("HOME", str(home_dir))
+
+    monkeypatch.setenv("GIT_CONFIG_NOSYSTEM", "1")
+    contents = b"""
+[user]
+name=GTO Tester
+[email protected]
+"""
+    (home_dir / ".gitconfig").write_bytes(contents)
+    pygit2.settings.search_path[pygit2.GIT_CONFIG_LEVEL_GLOBAL] = str(home_dir)
+
+    yield
+    monkeypatch.undo()
+
+
 @pytest.fixture
 def scm(tmp_dir: TmpDir) -> Git:
     scm_instance = Git.init(tmp_dir)