refactor: enforce 800 line source limits

server/tests/test_code_size_limits.py

@@ -0,0 +1,34 @@
+from __future__ import annotations
+
+import ast
+from pathlib import Path
+
+
+MAX_CLASS_LINES = 800
+SERVER_SOURCE_ROOT = Path(__file__).resolve().parents[1] / "src" / "app"
+
+
+def iter_python_source_files(root: Path) -> list[Path]:
+    ignored_parts = {"__pycache__", "x_financial_server.egg-info"}
+    return sorted(
+        path
+        for path in root.rglob("*.py")
+        if not ignored_parts.intersection(path.parts)
+    )
+
+
+def test_python_classes_do_not_exceed_800_lines() -> None:
+    oversized_classes: list[str] = []
+
+    for path in iter_python_source_files(SERVER_SOURCE_ROOT):
+        tree = ast.parse(path.read_text(encoding="utf-8"))
+        for node in ast.walk(tree):
+            if isinstance(node, ast.ClassDef) and node.end_lineno is not None:
+                line_count = node.end_lineno - node.lineno + 1
+                if line_count > MAX_CLASS_LINES:
+                    relative_path = path.relative_to(SERVER_SOURCE_ROOT.parents[1])
+                    oversized_classes.append(
+                        f"{relative_path}:{node.lineno} {node.name} ({line_count} lines)"
+                    )
+
+    assert oversized_classes == []