fix: PS 5.1 compat — replace non-ASCII chars in shipped PowerShell scripts (#2709)

* Initial plan

* fix: replace non-ASCII chars in PS1 files, add encoding regression tests, fix ANSI stripping in tests, update docs

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>

tests/integrations/test_cli.py

@@ -335,10 +335,11 @@ class TestInitIntegrationFlag:
         _install_shared_infra(project, "sh", force=False)
 
         captured = capsys.readouterr()
-        assert "already exist and were not updated" in captured.out
-        assert "specify init --here --force" in captured.out
+        plain = strip_ansi(captured.out)
+        assert "already exist and were not updated" in plain
+        assert "specify init --here --force" in plain
         # Rich may wrap long lines; normalize whitespace for the second command
-        normalized = " ".join(captured.out.split())
+        normalized = " ".join(plain.split())
         assert "specify integration upgrade --force" in normalized
 
     def test_shared_infra_warns_when_manifest_cannot_be_loaded(self, tmp_path, capsys):

tests/integrations/test_integration_subcommand.py

@@ -7,6 +7,7 @@ import pytest
 from typer.testing import CliRunner
 
 from specify_cli import app
+from tests.conftest import strip_ansi
 
 
 runner = CliRunner()
@@ -49,7 +50,8 @@ def _write_invalid_manifest(project, key):
 
 
 def _integration_list_row_cells(output: str, key: str) -> list[str]:
-    row = next(line for line in output.splitlines() if line.startswith(f"│ {key}"))
+    plain = strip_ansi(output)
+    row = next(line for line in plain.splitlines() if line.startswith(f"│ {key}"))
     return [cell.strip() for cell in row.split("│")[1:-1]]
 
 
@@ -160,8 +162,9 @@ class TestIntegrationInstall:
         finally:
             os.chdir(old_cwd)
         assert result.exit_code == 0
-        assert "already installed" in result.output
-        normalized = " ".join(result.output.split())
+        plain = strip_ansi(result.output)
+        assert "already installed" in plain
+        normalized = " ".join(plain.split())
         assert "specify integration upgrade copilot" in normalized
         assert "already the default integration" in normalized
         assert "No files were changed" in normalized
@@ -197,9 +200,10 @@ class TestIntegrationInstall:
         finally:
             os.chdir(old_cwd)
         assert result.exit_code != 0
-        assert "Installed integrations: copilot" in result.output
-        assert "Default integration: copilot" in result.output
-        normalized = " ".join(result.output.split())
+        plain = strip_ansi(result.output)
+        assert "Installed integrations: copilot" in plain
+        assert "Default integration: copilot" in plain
+        normalized = " ".join(plain.split())
         assert "To replace the default integration" in normalized
         assert "specify integration switch claude" in normalized
         assert "To install 'claude' alongside" in normalized
@@ -309,9 +313,10 @@ class TestIntegrationInstall:
         finally:
             os.chdir(old_cwd)
         assert result.exit_code != 0
-        assert "Installed integrations: copilot" in result.output
-        assert "multi-install safe" in result.output
-        normalized = " ".join(result.output.split())
+        plain = strip_ansi(result.output)
+        assert "Installed integrations: copilot" in plain
+        assert "multi-install safe" in plain
+        normalized = " ".join(plain.split())
         assert "To replace the default integration" in normalized
         assert "specify integration switch claude" in normalized
         assert "To install 'claude' alongside" in normalized

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