clean poetry.vcs.git.system module and add tests (#8401)

src/poetry/vcs/git/system.py

@@ -22,21 +22,8 @@ def clone(cls, repository: str, dest: Path) -> str:
 
     @classmethod
     def checkout(cls, rev: str, target: Path | None = None) -> str:
-        args = []
-
-        if target:
-            args += [
-                "--git-dir",
-                (target / ".git").as_posix(),
-                "--work-tree",
-                target.as_posix(),
-            ]
-
         cls._check_parameter(rev)
-
-        args += ["checkout", rev]
-
-        return cls.run(*args)
+        return cls.run("checkout", rev, folder=target)
 
     @staticmethod
     def run(*args: Any, **kwargs: Any) -> str:

tests/vcs/git/test_system.py

@@ -0,0 +1,97 @@
+from __future__ import annotations
+
+import re
+import shutil
+import subprocess
+import typing
+
+import dulwich.repo
+import pytest
+
+from poetry.vcs.git.system import SystemGit
+
+
+if typing.TYPE_CHECKING:
+    from pathlib import Path
+
+
+GIT_NOT_INSTALLLED = shutil.which("git") is None
+
+
+def get_head_sha(cwd: Path) -> str:
+    return subprocess.check_output(
+        ["git", "rev-parse", "HEAD"],
+        cwd=cwd,
+        text=True,
+    ).strip()
+
+
+class TempRepoFixture(typing.NamedTuple):
+    path: Path
+    repo: dulwich.repo.Repo
+    init_commit: str
+    head_commit: str
+
+
+@pytest.fixture()
+def temp_repo(tmp_path: Path) -> TempRepoFixture:
+    """Temporary repository with 2 commits"""
+    repo = dulwich.repo.Repo.init(str(tmp_path))
+
+    # init commit
+    (tmp_path / "foo").write_text("foo")
+    repo.stage(["foo"])
+
+    init_commit = repo.do_commit(
+        committer=b"User <[email protected]>",
+        author=b"User <[email protected]>",
+        message=b"init",
+        no_verify=True,
+    )
+
+    # extra commit
+    (tmp_path / "foo").write_text("bar")
+    repo.stage(["foo"])
+
+    head_commit = repo.do_commit(
+        committer=b"User <[email protected]>",
+        author=b"User <[email protected]>",
+        message=b"extra",
+        no_verify=True,
+    )
+
+    return TempRepoFixture(
+        path=tmp_path,
+        repo=repo,
+        init_commit=init_commit.decode(),
+        head_commit=head_commit.decode(),
+    )
+
+
+@pytest.mark.skipif(GIT_NOT_INSTALLLED, reason="These tests requires git cli")
+class TestSystemGit:
+    def test_clone_success(self, tmp_path: Path, temp_repo: TempRepoFixture) -> None:
+        target_dir = tmp_path / "test-repo"
+        stdout = SystemGit.clone(temp_repo.path.as_uri(), target_dir)
+        assert re.search(r"Cloning into '.+[\\/]test-repo'...", stdout)
+        assert (target_dir / ".git").is_dir()
+
+    def test_clone_invalid_parameter(self, tmp_path: Path) -> None:
+        with pytest.raises(
+            RuntimeError, match=re.escape("Invalid Git parameter: --upload-pack")
+        ):
+            SystemGit.clone("--upload-pack=touch ./HELL", tmp_path)
+
+    def test_checkout_1(self, temp_repo: TempRepoFixture) -> None:
+        # case 1 - with 'target' arg
+        SystemGit.checkout(temp_repo.init_commit[:12], temp_repo.path)
+        assert get_head_sha(temp_repo.path) == temp_repo.init_commit
+
+    def test_checkout_2(
+        self, monkeypatch: pytest.MonkeyPatch, temp_repo: TempRepoFixture
+    ) -> None:
+        # case 2 - without 'target' arg
+        monkeypatch.chdir(temp_repo.path)
+
+        SystemGit.checkout(temp_repo.init_commit[:12])
+        assert get_head_sha(temp_repo.path) == temp_repo.init_commit