doc updates. don't trigger on open_nursery in 102 (it didn't work anyway). async112 error message now specifies if its nursery or taskgroup.

Author: jakkdl

docs/rules.rst

@@ -55,6 +55,8 @@ ASYNC112 : useless-nursery
 
 _`ASYNC113` : start-soon-in-aenter
     Using :meth:`~trio.Nursery.start_soon`/:meth:`~anyio.abc.TaskGroup.start_soon` in ``__aenter__`` doesn't wait for the task to begin.
+    This will only warn about built-in functions and those listed in _`ASYNC114`.
+    If you're starting a function that does not define `task_status`, then neither will trigger.
     Consider replacing with :meth:`~trio.Nursery.start`/:meth:`~anyio.abc.TaskGroup.start`.
 
 _`ASYNC114` : startable-not-in-config

docs/usage.rst

@@ -265,8 +265,9 @@ Example
 ``startable-in-context-manager``
 --------------------------------
 
-Comma-separated list of methods which should be used with :meth:`trio.Nursery.start`/:meth:`anyio.abc.TaskGroup.start` when opening a context manager,
-in addition to the default :func:`trio.run_process`, :func:`trio.serve_tcp`, :func:`trio.serve_ssl_over_tcp`, and :func:`trio.serve_listeners`.
+Comma-separated list of methods which should be used with :meth:`trio.Nursery.start`/:meth:`anyio.abc.TaskGroup.start` when opening a context manager.
+This includes startable functions in the trio and anyio standard library by default, namely :func:`trio.run_process`, :func:`trio.serve_tcp`, :func:`trio.serve_ssl_over_tcp`, :func:`trio.serve_listeners`, :func:`trio.serve`, :func:`anyio.run_process`, :func:`anyio.serve_tcp`, :func:`anyio.serve_ssl_over_tcp`, :func:`anyio.serve_listeners`, and :func:`anyio.serve`.
+
 Names must be valid identifiers as per :meth:`str.isidentifier`.
 Used by :ref:`ASYNC113 <async113>`, and :ref:`ASYNC114 <async114>` will warn when encountering methods not in the list.
 

flake8_async/visitors/visitor102.py

@@ -87,9 +87,7 @@ def visit_With(self, node: ast.With | ast.AsyncWith):
 
         # Check for a `with trio.<scope_creator>`
         for item in node.items:
-            call = get_matching_call(
-                item.context_expr, "open_nursery", *cancel_scope_names
-            )
+            call = get_matching_call(item.context_expr, *cancel_scope_names)
             if call is None:
                 continue
 

flake8_async/visitors/visitors.py

@@ -95,7 +95,7 @@ def visit_While(self, node: ast.While):
 class Visitor112(Flake8AsyncVisitor):
     error_codes: Mapping[str, str] = {
         "ASYNC112": (
-            "Redundant nursery {}, consider replacing with directly awaiting "
+            "Redundant {1} {0}, consider replacing with directly awaiting "
             "the function call."
         ),
     }
@@ -113,19 +113,21 @@ def visit_With(self, node: ast.With | ast.AsyncWith):
                 continue
             var_name = item.optional_vars.id
 
-            # check for trio.open_nursery and anyio.create_task_group
-            nursery = get_matching_call(
-                item.context_expr, "open_nursery", base="trio"
-            ) or get_matching_call(item.context_expr, "create_task_group", base="anyio")
             start_methods: tuple[str, ...] = ("start", "start_soon")
-            if nursery is None:
-                # check for asyncio.TaskGroup
-                nursery = get_matching_call(
-                    item.context_expr, "TaskGroup", base="asyncio"
-                )
-                if nursery is None:
-                    continue
+            # check for trio.open_nursery and anyio.create_task_group
+            if get_matching_call(item.context_expr, "open_nursery", base="trio"):
+                nursery_type = "nursery"
+
+            elif get_matching_call(
+                item.context_expr, "create_task_group", base="anyio"
+            ):
+                nursery_type = "taskgroup"
+            # check for asyncio.TaskGroup
+            elif get_matching_call(item.context_expr, "TaskGroup", base="asyncio"):
+                nursery_type = "taskgroup"
                 start_methods = ("create_task",)
+            else:
+                continue
 
             body_call = node.body[0].value
             if isinstance(body_call, ast.Await):
@@ -142,7 +144,7 @@ def visit_With(self, node: ast.With | ast.AsyncWith):
                     for n in self.walk(*body_call.args, *body_call.keywords)
                 )
             ):
-                self.error(item.context_expr, var_name)
+                self.error(item.context_expr, var_name, nursery_type)
 
     visit_AsyncWith = visit_With
 

tests/eval_files/async102.py

@@ -111,7 +111,9 @@ async def foo():
         myvar = True
         with trio.open_nursery(10) as s:
             s.shield = myvar
-            await foo()  # safe in theory, error: 12, Statement("try/finally", lineno-6)
+            # this is not safe in theory - because `trio.open_nursery` is an async cm,
+            # so it's not possible to open a nursery at all.
+            await foo()  # error: 12, Statement("try/finally", lineno-8)
     try:
         pass
     finally: