lint: check @view_config.renderer filenames (#18366)

Author: miketheman

dev/flake8/checkers.py

@@ -8,6 +8,8 @@
 """
 
 import ast
+from pathlib import Path
+from textwrap import dedent  # for testing
 
 from collections.abc import Generator
 from typing import Any
@@ -17,6 +19,7 @@
     "WH002 Prefer `sqlalchemy.orm.relationship(back_populates=...)` "
     "over `sqlalchemy.orm.relationship(backref=...)`"
 )
+WH003_msg = "WH003 `@view_config.renderer` configured template file not found"
 
 
 class WarehouseVisitor(ast.NodeVisitor):
@@ -47,6 +50,24 @@ def _check_keywords(keywords: list[ast.keyword]) -> None:
             ):
                 _check_keywords(node.value.keywords)
 
+    def template_exists(self, template_name: str) -> bool:
+        settings = {}
+        # TODO: Replace with actual configuration retrieval if it makes sense
+        # Get Jinja2 search paths from warehouse config
+        # settings = configure().get_settings()
+        search_paths = settings.get("jinja2.searchpath", [])
+        # If not set, fallback to default templates path
+        if not search_paths:
+            repo_root = Path(__file__).parent.parent.parent
+            search_paths = [
+                str(repo_root / "warehouse" / "templates"),
+                str(repo_root / "warehouse" / "admin" / "templates"),
+            ]
+        for path in search_paths:
+            if Path(path, template_name).is_file():
+                return True
+        return False
+
     def visit_Name(self, node: ast.Name) -> None:  # noqa: N802
         if node.id == "urlparse":
             self.errors.append((node.lineno, node.col_offset, WH001_msg))
@@ -71,6 +92,25 @@ def visit_AnnAssign(self, node: ast.AnnAssign) -> None:  # noqa: N802
         self.check_for_backref(node)
         self.generic_visit(node)
 
+    def visit_FunctionDef(self, node: ast.FunctionDef) -> None:  # noqa: N802
+        for decorator in node.decorator_list:
+            if (
+                isinstance(decorator, ast.Call)
+                and getattr(decorator.func, "id", None) == "view_config"
+            ):
+                for kw in decorator.keywords:
+                    if (
+                        kw.arg == "renderer"
+                        and isinstance(kw.value, ast.Constant)
+                        # TODO: Is there a "string-that-looks-like-a-filename"?
+                        and kw.value.value not in ["json", "xmlrpc", "string"]
+                    ):
+                        if not self.template_exists(kw.value.value):
+                            self.errors.append(
+                                (kw.value.lineno, kw.value.col_offset, WH003_msg)
+                            )
+        self.generic_visit(node)
+
 
 class WarehouseCheck:
     def __init__(self, tree: ast.AST, filename: str) -> None:
@@ -83,3 +123,29 @@ def run(self) -> Generator[tuple[int, int, str, type[Any]]]:
 
         for e in visitor.errors:
             yield *e, type(self)
+
+
+# Testing
+def test_wh003_renderer_template_not_found():
+    # Simulate a Python file with a @view_config decorator and a non-existent template
+    code = dedent(
+        """
+    from pyramid.view import view_config
+
+    @view_config(renderer="non_existent_template.html")
+    def my_view(request):
+        pass
+    """
+    )
+    tree = ast.parse(code)
+    visitor = WarehouseVisitor(filename="test_file.py")
+    visitor.visit(tree)
+
+    # Assert that the WH003 error is raised
+    assert len(visitor.errors) == 1
+    assert visitor.errors[0][2] == WH003_msg
+
+
+if __name__ == "__main__":
+    test_wh003_renderer_template_not_found()
+    print("Test passed!")

setup.cfg

@@ -1,6 +1,6 @@
 [flake8]
 max-line-length = 88
-exclude = *.egg,*/interfaces.py,node_modules,.state
+exclude = *.egg,*/interfaces.py,node_modules,.state,.venv
 ignore = W503,E203,E701
 select = E,W,F,N,P
 per-file-ignores =