🐛 fix(scripts): force LF for generated text files

tests/test_script_line_endings.py

@@ -0,0 +1,79 @@
+import ast
+import unittest
+from pathlib import Path
+
+
+ROOT = Path(__file__).resolve().parents[1]
+SCRIPT_PATHS = sorted((ROOT / "scripts").glob("*.py")) + sorted(
+    (ROOT / ".gitea" / "ci").glob("*.py")
+)
+
+
+class ScriptLineEndingTests(unittest.TestCase):
+    def test_script_text_writes_pin_lf_newlines(self):
+        offenders: list[str] = []
+        for path in SCRIPT_PATHS:
+            tree = ast.parse(path.read_text(encoding="utf-8"))
+            for node in ast.walk(tree):
+                if not isinstance(node, ast.Call):
+                    continue
+                if is_write_text_without_lf_newline(node):
+                    offenders.append(f"{path.relative_to(ROOT)}:{node.lineno}")
+                elif is_text_open_for_writing_without_newline(node):
+                    offenders.append(f"{path.relative_to(ROOT)}:{node.lineno}")
+
+        self.assertEqual(offenders, [])
+
+
+def has_lf_newline_keyword(node: ast.Call) -> bool:
+    newline = next(
+        (keyword for keyword in node.keywords if keyword.arg == "newline"),
+        None,
+    )
+    return (
+        newline is not None
+        and isinstance(newline.value, ast.Constant)
+        and newline.value.value == "\n"
+    )
+
+
+def is_write_text_without_lf_newline(node: ast.Call) -> bool:
+    func = node.func
+    return (
+        isinstance(func, ast.Attribute)
+        and func.attr == "write_text"
+        and not has_lf_newline_keyword(node)
+    )
+
+
+def is_text_open_for_writing_without_newline(node: ast.Call) -> bool:
+    func = node.func
+    if isinstance(func, ast.Name):
+        is_open = func.id == "open"
+    elif isinstance(func, ast.Attribute):
+        is_open = func.attr == "open"
+    else:
+        is_open = False
+    if not is_open:
+        return False
+
+    mode_node = None
+    if len(node.args) >= 2:
+        mode_node = node.args[1]
+    for keyword in node.keywords:
+        if keyword.arg == "mode":
+            mode_node = keyword.value
+            break
+
+    if mode_node is None:
+        return False
+    if not isinstance(mode_node, ast.Constant) or not isinstance(mode_node.value, str):
+        return False
+
+    mode = mode_node.value
+    writes_text = any(flag in mode for flag in ("w", "a", "x")) and "b" not in mode
+    return writes_text and not has_lf_newline_keyword(node)
+
+
+if __name__ == "__main__":
+    unittest.main()