[packages] Resolve git symlinks on Windows when materialized as text (#16657)

tests/unit_tests/test_git.py

@@ -4,7 +4,7 @@ from datetime import datetime, timedelta
 import os
 from pathlib import Path
 from typing import Any
-from unittest.mock import Mock
+from unittest.mock import Mock, patch
 
 import pytest
 
@@ -1001,3 +1001,304 @@ def test_refresh_picks_up_new_remote_commits(
         "--hard",
         "old_sha",
     ]
+
+
+def test_resolve_symlink_stub_returns_none_on_non_windows(
+    tmp_path: Path, mock_run_git_command: Mock
+) -> None:
+    """On non-Windows, resolve_symlink_stub returns None without calling git."""
+    repo_dir = tmp_path / "repo"
+    repo_dir.mkdir()
+    stub = repo_dir / "file.yaml"
+    stub.write_text("static/file.yaml")
+
+    with patch("esphome.git.sys.platform", "linux"):
+        result = git.resolve_symlink_stub(repo_dir, stub)
+
+    assert result is None
+    mock_run_git_command.assert_not_called()
+
+
+def test_resolve_symlink_stub_returns_target_for_mode_120000(
+    tmp_path: Path, mock_run_git_command: Mock
+) -> None:
+    """A mode-120000 file is recognised as a stub; its target Path is returned."""
+    repo_dir = tmp_path / "repo"
+    repo_dir.mkdir()
+    (repo_dir / "static").mkdir()
+
+    target = repo_dir / "static" / "real.yaml"
+    target.write_text("esphome:\n  name: real\n")
+
+    stub = repo_dir / "real.yaml"
+    stub.write_text("static/real.yaml")
+
+    mock_run_git_command.return_value = "120000 abc123 0\treal.yaml"
+
+    with patch("esphome.git.sys.platform", "win32"):
+        result = git.resolve_symlink_stub(repo_dir, stub)
+
+    assert result == target.resolve()
+    # Stub file itself was not modified — only inspected.
+    assert stub.read_text() == "static/real.yaml"
+
+
+def test_resolve_symlink_stub_resolves_relative_parent_paths(
+    tmp_path: Path, mock_run_git_command: Mock
+) -> None:
+    """Symlink targets with ``..`` segments resolve correctly within the repo."""
+    repo_dir = tmp_path / "repo"
+    (repo_dir / "subdir").mkdir(parents=True)
+    (repo_dir / "static").mkdir()
+
+    target = repo_dir / "static" / "shared.yaml"
+    target.write_text("shared content")
+
+    stub = repo_dir / "subdir" / "shared.yaml"
+    stub.write_text("../static/shared.yaml")
+
+    mock_run_git_command.return_value = "120000 abc123 0\tsubdir/shared.yaml"
+
+    with patch("esphome.git.sys.platform", "win32"):
+        result = git.resolve_symlink_stub(repo_dir, stub)
+
+    assert result == target.resolve()
+
+
+def test_resolve_symlink_stub_refuses_escape_outside_repo(
+    tmp_path: Path, mock_run_git_command: Mock
+) -> None:
+    """A symlink pointing outside the repository is not followed."""
+    outside = tmp_path / "outside.yaml"
+    outside.write_text("sensitive")
+
+    repo_dir = tmp_path / "repo"
+    repo_dir.mkdir()
+
+    stub = repo_dir / "escape.yaml"
+    stub.write_text("../outside.yaml")
+
+    mock_run_git_command.return_value = "120000 abc123 0\tescape.yaml"
+
+    with patch("esphome.git.sys.platform", "win32"):
+        result = git.resolve_symlink_stub(repo_dir, stub)
+
+    assert result is None
+
+
+def test_resolve_symlink_stub_returns_none_for_real_symlink(
+    tmp_path: Path, mock_run_git_command: Mock
+) -> None:
+    """A real symlink already opens transparently, so the helper short-circuits.
+
+    Skipped on Windows where symlink creation requires
+    SeCreateSymbolicLinkPrivilege.
+    """
+    if os.name == "nt":
+        pytest.skip("Requires symlink-creation privilege on Windows")
+
+    repo_dir = tmp_path / "repo"
+    repo_dir.mkdir()
+    target = repo_dir / "real.yaml"
+    target.write_text("real content")
+
+    real_link = repo_dir / "link.yaml"
+    real_link.symlink_to("real.yaml")
+
+    with patch("esphome.git.sys.platform", "win32"):
+        result = git.resolve_symlink_stub(repo_dir, real_link)
+
+    assert result is None
+    # No git call needed for real symlinks.
+    mock_run_git_command.assert_not_called()
+
+
+def test_resolve_symlink_stub_returns_none_for_regular_file(
+    tmp_path: Path, mock_run_git_command: Mock
+) -> None:
+    """A regular file (mode 100644) whose content looks path-shaped is not
+    followed."""
+    repo_dir = tmp_path / "repo"
+    repo_dir.mkdir()
+
+    regular = repo_dir / "looks_like_path.txt"
+    regular.write_text("static/something.yaml")
+
+    mock_run_git_command.return_value = "100644 abc123 0\tlooks_like_path.txt"
+
+    with patch("esphome.git.sys.platform", "win32"):
+        result = git.resolve_symlink_stub(repo_dir, regular)
+
+    assert result is None
+
+
+def test_resolve_symlink_stub_returns_none_when_git_fails(
+    tmp_path: Path, mock_run_git_command: Mock
+) -> None:
+    """If ``git ls-files`` fails (e.g. not a repo), the helper returns None."""
+    repo_dir = tmp_path / "repo"
+    repo_dir.mkdir()
+
+    stub = repo_dir / "real.yaml"
+    stub.write_text("static/real.yaml")
+
+    mock_run_git_command.side_effect = GitCommandError("ls-files exploded")
+
+    with patch("esphome.git.sys.platform", "win32"):
+        result = git.resolve_symlink_stub(repo_dir, stub)
+
+    assert result is None
+
+
+def test_resolve_symlink_stub_returns_none_for_non_utf8_content(
+    tmp_path: Path, mock_run_git_command: Mock
+) -> None:
+    """A file whose bytes are not valid UTF-8 must not raise — return None."""
+    repo_dir = tmp_path / "repo"
+    repo_dir.mkdir()
+
+    stub = repo_dir / "binary.bin"
+    stub.write_bytes(b"\xff\xfe\x00\xff")
+
+    mock_run_git_command.return_value = "120000 abc123 0\tbinary.bin"
+
+    with patch("esphome.git.sys.platform", "win32"):
+        result = git.resolve_symlink_stub(repo_dir, stub)
+
+    assert result is None
+
+
+def test_resolve_symlink_stub_preserves_whitespace_in_target(
+    tmp_path: Path, mock_run_git_command: Mock
+) -> None:
+    """Only trailing CR/LF is stripped — internal whitespace is preserved."""
+    repo_dir = tmp_path / "repo"
+    repo_dir.mkdir()
+    target_dir = repo_dir / "dir with spaces"
+    target_dir.mkdir()
+    target = target_dir / "real.yaml"
+    target.write_text("hello")
+
+    stub = repo_dir / "link.yaml"
+    # Trailing newline (as git's checkout may append) is stripped, but
+    # whitespace inside the target path itself must survive.
+    stub.write_bytes(b"dir with spaces/real.yaml\n")
+
+    mock_run_git_command.return_value = "120000 abc123 0\tlink.yaml"
+
+    with patch("esphome.git.sys.platform", "win32"):
+        result = git.resolve_symlink_stub(repo_dir, stub)
+
+    assert result == target.resolve()
+
+
+def test_resolve_symlink_stub_returns_none_for_directory_target(
+    tmp_path: Path, mock_run_git_command: Mock
+) -> None:
+    """A symlink pointing at a directory has no file content to load."""
+    repo_dir = tmp_path / "repo"
+    repo_dir.mkdir()
+    (repo_dir / "dir_target").mkdir()
+
+    stub = repo_dir / "link_to_dir"
+    stub.write_text("dir_target")
+
+    mock_run_git_command.return_value = "120000 abc123 0\tlink_to_dir"
+
+    with patch("esphome.git.sys.platform", "win32"):
+        result = git.resolve_symlink_stub(repo_dir, stub)
+
+    assert result is None
+
+
+def test_resolve_symlink_stub_returns_none_when_resolve_raises(
+    tmp_path: Path, mock_run_git_command: Mock
+) -> None:
+    """Path.resolve() raising (e.g. on a malformed target) must not propagate."""
+    repo_dir = tmp_path / "repo"
+    repo_dir.mkdir()
+
+    stub = repo_dir / "broken.yaml"
+    stub.write_text("ignored")
+
+    mock_run_git_command.return_value = "120000 abc123 0\tbroken.yaml"
+
+    with (
+        patch("esphome.git.sys.platform", "win32"),
+        patch.object(Path, "resolve", side_effect=OSError("bad path")),
+    ):
+        result = git.resolve_symlink_stub(repo_dir, stub)
+
+    assert result is None
+
+
+def test_resolve_symlink_stub_returns_none_when_file_missing(
+    tmp_path: Path, mock_run_git_command: Mock
+) -> None:
+    """A file path that doesn't exist is rejected before git is consulted."""
+    repo_dir = tmp_path / "repo"
+    repo_dir.mkdir()
+
+    missing = repo_dir / "ghost.yaml"  # not created
+
+    with patch("esphome.git.sys.platform", "win32"):
+        result = git.resolve_symlink_stub(repo_dir, missing)
+
+    assert result is None
+    mock_run_git_command.assert_not_called()
+
+
+def test_resolve_symlink_stub_returns_none_when_path_outside_repo(
+    tmp_path: Path, mock_run_git_command: Mock
+) -> None:
+    """A file path that isn't under repo_dir is rejected (ValueError from relative_to)."""
+    repo_dir = tmp_path / "repo"
+    repo_dir.mkdir()
+
+    outside = tmp_path / "stray.yaml"
+    outside.write_text("something")
+
+    with patch("esphome.git.sys.platform", "win32"):
+        result = git.resolve_symlink_stub(repo_dir, outside)
+
+    assert result is None
+    mock_run_git_command.assert_not_called()
+
+
+def test_resolve_symlink_stub_returns_none_when_untracked(
+    tmp_path: Path, mock_run_git_command: Mock
+) -> None:
+    """Empty `git ls-files` output (untracked file) makes the helper return None."""
+    repo_dir = tmp_path / "repo"
+    repo_dir.mkdir()
+
+    stub = repo_dir / "untracked.yaml"
+    stub.write_text("static/foo.yaml")
+
+    mock_run_git_command.return_value = ""
+
+    with patch("esphome.git.sys.platform", "win32"):
+        result = git.resolve_symlink_stub(repo_dir, stub)
+
+    assert result is None
+
+
+def test_resolve_symlink_stub_returns_none_when_read_bytes_raises(
+    tmp_path: Path, mock_run_git_command: Mock
+) -> None:
+    """An OSError from read_bytes() (e.g. file vanished mid-call) must not propagate."""
+    repo_dir = tmp_path / "repo"
+    repo_dir.mkdir()
+
+    stub = repo_dir / "racy.yaml"
+    stub.write_text("static/racy.yaml")
+
+    mock_run_git_command.return_value = "120000 abc123 0\tracy.yaml"
+
+    with (
+        patch("esphome.git.sys.platform", "win32"),
+        patch.object(Path, "read_bytes", side_effect=OSError("vanished")),
+    ):
+        result = git.resolve_symlink_stub(repo_dir, stub)
+
+    assert result is None