chore: import upstream snapshot with attribution

tests/test_ps1_encoding.py

@@ -0,0 +1,54 @@
+"""Regression tests for PowerShell 5.1 compatibility (GitHub issue #2680).
+
+PowerShell 5.1 (built-in on Windows) defaults to the system's legacy encoding
+when reading .ps1 files.  Non-ASCII characters in UTF-8-encoded scripts cause
+parse errors because multi-byte sequences are misinterpreted as individual bytes.
+
+These tests ensure that all shipped .ps1 files remain ASCII-only so they work
+on both PowerShell 5.1 and 7+.
+"""
+
+from pathlib import Path
+
+import pytest
+
+REPO_ROOT = Path(__file__).resolve().parent.parent
+
+# All directories that contain shipped PowerShell scripts.
+_PS1_DIRS = [
+    REPO_ROOT / "scripts" / "powershell",
+    REPO_ROOT / "extensions" / "git" / "scripts" / "powershell",
+]
+
+
+def _collect_ps1_files():
+    """Yield all .ps1 files under the known script directories."""
+    for d in _PS1_DIRS:
+        if d.is_dir():
+            yield from sorted(d.rglob("*.ps1"))
+
+
+_PS1_FILES = list(_collect_ps1_files())
+
+
+@pytest.mark.parametrize("ps1_file", _PS1_FILES, ids=lambda p: str(p.relative_to(REPO_ROOT)))
+def test_ps1_file_is_ascii_only(ps1_file: Path):
+    """Every .ps1 file must contain only ASCII characters (PS 5.1 compat)."""
+    content = ps1_file.read_bytes()
+    non_ascii = [
+        (i + 1, byte)
+        for i, byte in enumerate(content)
+        if byte > 127
+    ]
+    assert not non_ascii, (
+        f"{ps1_file.relative_to(REPO_ROOT)} contains non-ASCII bytes "
+        f"(PowerShell 5.1 incompatible): "
+        f"first at byte offset {non_ascii[0][0]} (0x{non_ascii[0][1]:02x})"
+    )
+
+
+def test_ps1_files_discovered():
+    """Sanity check: at least the known script files are found."""
+    names = {p.name for p in _PS1_FILES}
+    assert "common.ps1" in names
+    assert "initialize-repo.ps1" in names