Fixups and improvements to git info retrieval (#991)

# Pull Request

## Title

Fixups and improvements to git info retrieval

______________________________________________________________________

## Description

Various fixups and improvements to git info retrieval:

Test and handle cases where the local git repo has no upstream or the
upstream is not "origin".

______________________________________________________________________

## Type of Change

- 🛠️ Bug fix
- 🔄 Refactor
- 🧪 Tests

______________________________________________________________________

## Testing

- CI
- New unit tests

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## Additional Notes (optional)

To be merged before #985 

______________________________________________________________________

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

Author: bpkroth

mlos_bench/mlos_bench/storage/base_storage.py

@@ -194,7 +194,7 @@ def __init__(  # pylint: disable=too-many-arguments
             self._tunables = tunables.copy()
             self._trial_id = trial_id
             self._experiment_id = experiment_id
-            (self._git_repo, self._git_commit, self._root_env_config) = get_git_info(
+            (self._git_repo, self._git_commit, self._root_env_config, _future_pr) = get_git_info(
                 root_env_config
             )
             self._description = description

mlos_bench/mlos_bench/tests/util_git_test.py

@@ -3,14 +3,95 @@
 # Licensed under the MIT License.
 #
 """Unit tests for get_git_info utility function."""
+import os
 import re
+import tempfile
+from pathlib import Path
+from subprocess import CalledProcessError
+from subprocess import check_call as run
 
-from mlos_bench.util import get_git_info
+import pytest
+
+from mlos_bench.util import get_git_info, get_git_root, path_join
 
 
 def test_get_git_info() -> None:
-    """Check that we can retrieve git info about the current repository correctly."""
-    (git_repo, git_commit, rel_path) = get_git_info(__file__)
+    """Check that we can retrieve git info about the current repository correctly from a
+    file.
+    """
+    (git_repo, git_commit, rel_path, abs_path) = get_git_info(__file__)
     assert "mlos" in git_repo.lower()
     assert re.match(r"[0-9a-f]{40}", git_commit) is not None
     assert rel_path == "mlos_bench/mlos_bench/tests/util_git_test.py"
+    assert abs_path == path_join(__file__, abs_path=True)
+
+
+def test_get_git_info_dir() -> None:
+    """Check that we can retrieve git info about the current repository correctly from a
+    directory.
+    """
+    dirname = os.path.dirname(__file__)
+    (git_repo, git_commit, rel_path, abs_path) = get_git_info(dirname)
+    assert "mlos" in git_repo.lower()
+    assert re.match(r"[0-9a-f]{40}", git_commit) is not None
+    assert rel_path == "mlos_bench/mlos_bench/tests"
+    assert abs_path == path_join(dirname, abs_path=True)
+
+
+def test_non_git_dir() -> None:
+    """Check that we can handle a non-git directory."""
+    with tempfile.TemporaryDirectory() as non_git_dir:
+        with pytest.raises(CalledProcessError):
+            # This should raise an error because the directory is not a git repository.
+            get_git_root(non_git_dir)
+
+
+def test_non_upstream_git() -> None:
+    """Check that we can handle a git directory without an upstream."""
+    with tempfile.TemporaryDirectory() as local_git_dir:
+        local_git_dir = path_join(local_git_dir, abs_path=True)
+        # Initialize a new git repository.
+        run(["git", "init", local_git_dir, "-b", "main"])
+        run(["git", "-C", local_git_dir, "config", "--local", "user.email", "pytest@example.com"])
+        run(["git", "-C", local_git_dir, "config", "--local", "user.name", "PyTest User"])
+        Path(local_git_dir).joinpath("README.md").touch()
+        run(["git", "-C", local_git_dir, "add", "README.md"])
+        run(["git", "-C", local_git_dir, "commit", "-m", "Initial commit"])
+        # This should have slightly different behavior when there is no upstream.
+        (git_repo, _git_commit, rel_path, abs_path) = get_git_info(local_git_dir)
+        assert git_repo == f"file://{local_git_dir}"
+        assert abs_path == local_git_dir
+        assert rel_path == "."
+
+
+@pytest.mark.skipif(
+    os.environ.get("GITHUB_ACTIONS") != "true",
+    reason="Not running in GitHub Actions CI.",
+)
+def test_github_actions_git_info() -> None:
+    """
+    Test that get_git_info matches GitHub Actions environment variables if running in
+    CI.
+
+    Examples
+    --------
+    Test locally with the following command:
+
+    .. code-block:: shell
+
+        export GITHUB_ACTIONS=true
+        export GITHUB_SHA=$(git rev-parse HEAD)
+        # GITHUB_REPOSITORY should be in "owner/repo" format.
+        # e.g., GITHUB_REPOSITORY="bpkroth/MLOS" or "microsoft/MLOS"
+        export GITHUB_REPOSITORY=$(git rev-parse --abbrev-ref --symbolic-full-name HEAD@{u} | cut -d/ -f1 | xargs git remote get-url | grep https://github.com | cut -d/ -f4-)
+        pytest -n0 mlos_bench/mlos_bench/tests/util_git_test.py
+    """  # pylint: disable=line-too-long # noqa: E501
+    repo_env = os.environ.get("GITHUB_REPOSITORY")  # "owner/repo" format
+    sha_env = os.environ.get("GITHUB_SHA")
+    assert repo_env, "GITHUB_REPOSITORY not set in environment."
+    assert sha_env, "GITHUB_SHA not set in environment."
+    git_repo, git_commit, _rel_path, _abs_path = get_git_info(__file__)
+    assert git_repo.endswith(repo_env), f"git_repo '{git_repo}' does not end with '{repo_env}'"
+    assert (
+        git_commit == sha_env
+    ), f"git_commit '{git_commit}' does not match GITHUB_SHA '{sha_env}'"

mlos_bench/mlos_bench/util.py

@@ -153,7 +153,7 @@ def path_join(*args: str, abs_path: bool = False) -> str:
     """
     path = os.path.join(*args)
     if abs_path:
-        path = os.path.abspath(path)
+        path = os.path.realpath(path)
     return os.path.normpath(path).replace("\\", "/")
 
 
@@ -274,33 +274,150 @@ def check_required_params(config: Mapping[str, Any], required_params: Iterable[s
         )
 
 
-def get_git_info(path: str = __file__) -> tuple[str, str, str]:
+def get_git_root(path: str = __file__) -> str:
     """
-    Get the git repository, commit hash, and local path of the given file.
+    Get the root dir of the git repository.
+
+    Parameters
+    ----------
+    path : Optional[str]
+        Path to the file in git repository.
+
+    Raises
+    ------
+    subprocess.CalledProcessError
+        If the path is not a git repository or the command fails.
+
+    Returns
+    -------
+    str
+        The absolute path to the root directory of the git repository.
+    """
+    abspath = path_join(path, abs_path=True)
+    if not os.path.exists(abspath) or not os.path.isdir(abspath):
+        dirname = os.path.dirname(abspath)
+    else:
+        dirname = abspath
+    git_root = subprocess.check_output(
+        ["git", "-C", dirname, "rev-parse", "--show-toplevel"], text=True
+    ).strip()
+    return path_join(git_root, abs_path=True)
+
+
+def get_git_remote_info(path: str, remote: str) -> str:
+    """
+    Gets the remote URL for the given remote name in the git repository.
 
     Parameters
     ----------
     path : str
         Path to the file in git repository.
+    remote : str
+        The name of the remote (e.g., "origin").
+
+    Raises
+    ------
+    subprocess.CalledProcessError
+        If the command fails or the remote does not exist.
 
     Returns
     -------
-    (git_repo, git_commit, git_path) : tuple[str, str, str]
-        Git repository URL, last commit hash, and relative file path.
+    str
+        The URL of the remote repository.
     """
-    dirname = os.path.dirname(path)
-    git_repo = subprocess.check_output(
-        ["git", "-C", dirname, "remote", "get-url", "origin"], text=True
+    return subprocess.check_output(
+        ["git", "-C", path, "remote", "get-url", remote], text=True
     ).strip()
+
+
+def get_git_repo_info(path: str) -> str:
+    """
+    Get the git repository URL for the given git repo.
+
+    Tries to get the upstream branch URL, falling back to the "origin" remote
+    if the upstream branch is not set or does not exist. If that also fails,
+    it returns a file URL pointing to the local path.
+
+    Parameters
+    ----------
+    path : str
+        Path to the git repository.
+
+    Raises
+    ------
+    subprocess.CalledProcessError
+        If the command fails or the git repository does not exist.
+
+    Returns
+    -------
+    str
+        The upstream URL of the git repository.
+    """
+    # In case "origin" remote is not set, or this branch has a different
+    # upstream, we should handle it gracefully.
+    # (e.g., fallback to the first one we find?)
+    path = path_join(path, abs_path=True)
+    cmd = ["git", "-C", path, "rev-parse", "--abbrev-ref", "--symbolic-full-name", "HEAD@{u}"]
+    try:
+        git_remote = subprocess.check_output(cmd, text=True).strip()
+        git_remote = git_remote.split("/", 1)[0]
+        git_repo = get_git_remote_info(path, git_remote)
+    except subprocess.CalledProcessError:
+        git_remote = "origin"
+        _LOG.warning(
+            "Failed to get the upstream branch for %s. Falling back to '%s' remote.",
+            path,
+            git_remote,
+        )
+        try:
+            git_repo = get_git_remote_info(path, git_remote)
+        except subprocess.CalledProcessError:
+            git_repo = "file://" + path
+            _LOG.warning(
+                "Failed to get the upstream branch for %s. Falling back to '%s'.",
+                path,
+                git_repo,
+            )
+    return git_repo
+
+
+def get_git_info(path: str = __file__) -> tuple[str, str, str, str]:
+    """
+    Get the git repository, commit hash, and local path of the given file.
+
+    Parameters
+    ----------
+    path : str
+        Path to the file in git repository.
+
+    Raises
+    ------
+    subprocess.CalledProcessError
+        If the path is not a git repository or the command fails.
+
+    Returns
+    -------
+    (git_repo, git_commit, rel_path, abs_path) : tuple[str, str, str, str]
+        Git repository URL, last commit hash, and relative file path and current
+        absolute path.
+    """
+    abspath = path_join(path, abs_path=True)
+    if os.path.exists(abspath) and os.path.isdir(abspath):
+        dirname = abspath
+    else:
+        dirname = os.path.dirname(abspath)
+    git_root = get_git_root(path=abspath)
+    git_repo = get_git_repo_info(git_root)
     git_commit = subprocess.check_output(
         ["git", "-C", dirname, "rev-parse", "HEAD"], text=True
     ).strip()
-    git_root = subprocess.check_output(
-        ["git", "-C", dirname, "rev-parse", "--show-toplevel"], text=True
-    ).strip()
-    _LOG.debug("Current git branch: %s %s", git_repo, git_commit)
-    rel_path = os.path.relpath(os.path.abspath(path), os.path.abspath(git_root))
-    return (git_repo, git_commit, rel_path.replace("\\", "/"))
+    _LOG.debug("Current git branch for %s: %s %s", git_root, git_repo, git_commit)
+    rel_path = os.path.relpath(abspath, os.path.abspath(git_root))
+    # TODO: return the branch too?
+    return (git_repo, git_commit, rel_path.replace("\\", "/"), abspath)
+
+
+# TODO: Add support for checking out the branch locally.
 
 
 # Note: to avoid circular imports, we don't specify TunableValue here.