test(addon): static import-hygiene check across all bridge modules

AST-only test (no import, so it also covers the bpy-importing modules that plain
unit tests can't load) asserting every `<stdlib>.<attr>` reference is backed by
an import. Catches the exact class of bug that shipped the local-bake `re.sub`
without `import re` — verified it flags the pre-fix bridge_operators.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: dmitrat

OutWit.Render.BlenderAddon/Tests/test_module_import_hygiene.py

@@ -0,0 +1,61 @@
+from __future__ import annotations
+
+import ast
+import pathlib
+import unittest
+
+
+PACKAGE_ROOT = pathlib.Path(__file__).resolve().parents[1] / "outwit_render_bridge"
+
+# Stdlib modules the addon uses via ``<module>.<attr>``. A reference to any of these without a matching
+# import is a NameError the moment that code path runs — and because several addon modules ``import bpy``
+# they cannot be imported outside Blender, so a plain unit test never exercises them (this is exactly how
+# ``bridge_operators`` shipped a ``re.sub`` call with no ``import re``, crashing the local bake). This test
+# statically (AST-only, no import) verifies every such reference is backed by an import.
+_STDLIB_MODULES = {
+    "re", "os", "json", "sys", "subprocess", "math", "time", "glob",
+    "shutil", "tempfile", "pathlib", "uuid", "datetime", "collections",
+    "itertools", "io", "zipfile",
+}
+
+
+def _imported_names(tree: ast.AST) -> set[str]:
+    names: set[str] = set()
+    for node in ast.walk(tree):
+        if isinstance(node, ast.Import):
+            for alias in node.names:
+                names.add((alias.asname or alias.name).split(".")[0])
+        elif isinstance(node, ast.ImportFrom):
+            if node.module:
+                names.add(node.module.split(".")[0])
+            for alias in node.names:
+                names.add(alias.asname or alias.name)
+    return names
+
+
+def _stdlib_modules_used(tree: ast.AST) -> set[str]:
+    used: set[str] = set()
+    for node in ast.walk(tree):
+        if isinstance(node, ast.Attribute) and isinstance(node.value, ast.Name):
+            if node.value.id in _STDLIB_MODULES:
+                used.add(node.value.id)
+    return used
+
+
+class ModuleImportHygieneTests(unittest.TestCase):
+    def test_every_stdlib_module_used_is_imported(self) -> None:
+        modules = sorted(PACKAGE_ROOT.glob("*.py"))
+        self.assertGreater(len(modules), 0, f"no addon modules found under {PACKAGE_ROOT}")
+
+        problems: list[str] = []
+        for path in modules:
+            tree = ast.parse(path.read_text(encoding="utf-8"), str(path))
+            missing = _stdlib_modules_used(tree) - _imported_names(tree)
+            for module in sorted(missing):
+                problems.append(f"{path.name}: uses '{module}.' but never imports '{module}'")
+
+        self.assertEqual(problems, [], "missing stdlib imports:\n" + "\n".join(problems))
+
+
+if __name__ == "__main__":
+    unittest.main()