From c7bb973f851d8e532fe9d7c35aa61bf96ff72046 Mon Sep 17 00:00:00 2001
From: jakkdl <h6+github@pm.me>
Date: Fri, 17 Mar 2023 13:53:26 +0100
Subject: [PATCH] add tests for autofix files, fix 91x autofix, and rejig test
 files to accomodate the new tests

---
 CONTRIBUTING.md                               |   6 +-
 flake8_trio/visitors/visitor91x.py            | 309 +++++++++---------
 tests/autofix_files/trio100.py                |  16 +-
 tests/autofix_files/trio100.py.diff           |   6 +-
 tests/autofix_files/trio100_simple_autofix.py |   8 +-
 .../trio100_simple_autofix.py.diff            |   3 +-
 tests/autofix_files/trio910.py                |   1 +
 tests/autofix_files/trio910.py.diff           |  38 +--
 tests/autofix_files/trio911.py                |  43 +--
 tests/autofix_files/trio911.py.diff           | 153 ++++-----
 tests/autofix_files/trio91x_autofix.py        |  39 +--
 tests/autofix_files/trio91x_autofix.py.diff   |   8 +-
 tests/eval_files/trio100.py                   |  16 +-
 tests/eval_files/trio100_noautofix.py         |  24 ++
 tests/eval_files/trio100_simple_autofix.py    |   8 +-
 tests/eval_files/trio910.py                   |   1 +
 tests/eval_files/trio911.py                   |  37 +--
 tests/eval_files/trio91x_autofix.py           |  39 +--
 tests/eval_files/trio91x_noautofix.py         |  71 ++++
 tests/test_flake8_trio.py                     |  40 ++-
 20 files changed, 420 insertions(+), 446 deletions(-)
 create mode 100644 tests/eval_files/trio100_noautofix.py
 create mode 100644 tests/eval_files/trio91x_noautofix.py

diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 8abd2cc1..cb86fc78 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -32,8 +32,10 @@ To check that all codes are tested and documented there's a test that error code
 ## Test generator
 Tests are automatically generated for files in the `tests/eval_files/` directory, with the code that it's testing interpreted from the file name. The file extension is split off, if there's a match for for `_py\d*` it strips that off and uses it to determine if there's a minimum python version for which the test should only run.
 
-### autofix files
-Checks that have autofixing can have a file in the `tests/autofix_files` directory matching the filename in `tests/eval_files`. The result of running the checker on the eval file with autofix enabled will then be compared to the content of the autofix file and will print a diff (if `-s` is on) and assert that the content is the same. `--generate-autofix` is added as a pytest flag to ease development, which will print a diff (with `-s`) and overwrite the content of the autofix file. Also see the magic line marker `pass # AUTOFIX_LINE ` below
+### `# AUTOFIX`
+Files in `tests/eval_files` with this marker will have two files in `tests/autofix_files/`. One with the same name containing the code after being autofixed, and a diff file between those two.  
+During tests the result of running the checker on the eval file with autofix enabled will be compared to the content of the autofix file and will print a diff (if `-s` is on) and assert that the content is the same. `--generate-autofix` is added as a pytest flag to ease development, which will print a diff (with `-s`) and overwrite the content of the autofix file.  
+Files without this marker will be checked that they *don't* modify the file content.
 
 ### `error:`
 Lines containing `error:` are parsed as expecting an error of the code matching the file name, with everything on the line after the colon `eval`'d and passed as arguments to `flake8_trio.Error_codes[<error_code>].str_format`. The `globals` argument to `eval` contains a `lineno` variable assigned the current line number, and the `flake8_trio.Statement` namedtuple. The first element after `error:` *must* be an integer containing the column where the error on that line originates.
diff --git a/flake8_trio/visitors/visitor91x.py b/flake8_trio/visitors/visitor91x.py
index 64d24d15..a11ef79d 100644
--- a/flake8_trio/visitors/visitor91x.py
+++ b/flake8_trio/visitors/visitor91x.py
@@ -7,6 +7,7 @@
 
 from __future__ import annotations
 
+from abc import ABC, abstractmethod
 from dataclasses import dataclass, field
 from typing import TYPE_CHECKING, Any
 
@@ -32,7 +33,7 @@
 
 
 def func_empty_body(node: cst.FunctionDef) -> bool:
-    # Does the function body consist solely of `pass`, `...`, and (doc)string literals?
+    """Check if function body consist of `pass`, `...`, and/or (doc)string literals."""
     empty_statement = m.Pass() | m.Expr(m.Ellipsis() | m.SimpleString())
     return m.matches(
         node.body,
@@ -90,9 +91,125 @@ def checkpoint_statement(library: str) -> cst.SimpleStatementLine:
     )
 
 
+class CommonVisitors(cst.CSTTransformer, ABC):
+    """Base class for InsertCheckpointsInLoopBody and Visitor91X.
+
+    Contains the transform methods used to actually insert the checkpoints, as well
+    as making sure that the library used will get imported. Adding the library import
+    is done in Visitor91X.
+    """
+
+    def __init__(self):
+        super().__init__()
+        self.noautofix: bool = False
+        self.add_statement: cst.SimpleStatementLine | None = None
+
+        self.explicitly_imported_library: dict[str, bool] = {
+            "trio": False,
+            "anyio": False,
+        }
+        self.add_import: set[str] = set()
+
+        self.__booldepth = 0
+
+    @property
+    @abstractmethod
+    def library(self) -> tuple[str, ...]:
+        ...
+
+    # instead of trying to exclude yields found in all the weird places from
+    # setting self.add_statement, we instead clear it upon each new line.
+    # Several of them *could* be handled, e.g. `if ...: yield`, but
+    # that's uncommon enough we don't care about it.
+    def visit_SimpleStatementLine(self, node: cst.SimpleStatementLine):
+        self.add_statement = None
+
+    # insert checkpoint before yield with a flattensentinel, if indicated
+    def leave_SimpleStatementLine(
+        self,
+        original_node: cst.SimpleStatementLine,
+        updated_node: cst.SimpleStatementLine,
+    ) -> cst.SimpleStatementLine | cst.FlattenSentinel[cst.SimpleStatementLine]:
+        # possible TODO: generate an error if transforming+visiting is done in a
+        # single pass and emit-error-on-transform can be enabled/disabled. The error can't
+        # be generated in the yield/return since it doesn't know if it will be autofixed.
+        if self.add_statement is None:
+            return updated_node
+        curr_add_statement = self.add_statement
+        self.add_statement = None
+
+        # multiple statements on a single line is not handled
+        if len(updated_node.body) > 1:
+            return updated_node
+
+        self.ensure_imported_library()
+        return cst.FlattenSentinel([curr_add_statement, updated_node])
+
+    def visit_BooleanOperation(self, node: cst.BooleanOperation):
+        self.__booldepth += 1
+        self.noautofix = True
+
+    def leave_BooleanOperation(
+        self, original_node: cst.BooleanOperation, updated_node: cst.BooleanOperation
+    ):
+        assert self.__booldepth
+        self.__booldepth -= 1
+        if not self.__booldepth:
+            self.noautofix = False
+        return updated_node
+
+    def ensure_imported_library(self) -> None:
+        """Mark library for import.
+
+        Check that the library we'd use to insert checkpoints
+        is imported - if not, mark it to be inserted later.
+        """
+        assert self.library
+        if not self.explicitly_imported_library[self.library[0]]:
+            self.add_import.add(self.library[0])
+
+
+class InsertCheckpointsInLoopBody(CommonVisitors):
+    """Insert checkpoints in loop bodies.
+
+    This inserts checkpoints that it was not known on the first pass whether a
+    checkpoint would be necessary, i.e. no uncheckpointed statements as we started to
+    parse the loop, but then there's uncheckpointed statements on continue or as loop
+    body finishes.
+    Called from `leave_While` and `leave_For` in Visitor91X.
+    """
+
+    def __init__(
+        self,
+        nodes_needing_checkpoint: Sequence[cst.Yield | cst.Return],
+        library: tuple[str, ...],
+    ):
+        super().__init__()
+        self.nodes_needing_checkpoint = nodes_needing_checkpoint
+        self.__library = library
+
+    @property
+    def library(self) -> tuple[str, ...]:
+        return self.__library if self.__library else ("trio",)
+
+    def leave_Yield(
+        self,
+        original_node: cst.Yield,
+        updated_node: cst.Yield,
+    ) -> cst.Yield:
+        # Needs to be passed *original* node, since updated node is a copy
+        # which loses identity equality
+        if original_node in self.nodes_needing_checkpoint and not self.noautofix:
+            self.add_statement = checkpoint_statement(self.library[0])
+        return updated_node
+
+    # returns handled same as yield, but ofc needs to ignore types
+    leave_Return = leave_Yield  # type: ignore
+
+
 @error_class_cst
 @disabled_by_default
-class Visitor91X(Flake8TrioVisitor_cst):
+class Visitor91X(Flake8TrioVisitor_cst, CommonVisitors):
     error_codes = {
         "TRIO910": (
             "{0} from async function with no guaranteed checkpoint or exception "
@@ -112,69 +229,18 @@ def __init__(self, *args: Any, **kwargs: Any):
         self.uncheckpointed_statements: set[Statement] = set()
         self.comp_unknown = False
 
-        # these are file-wide, so intentionally not save-stated upon entry/exit
-        # of functions/loops/etc
-        self.explicitly_imported_library: dict[str, bool] = {
-            "trio": False,
-            "anyio": False,
-        }
-        self.add_import: set[str] = set()
-
-        # this one is not save-stated, but I fail to come up with any scenario
-        # where that matters
-        self.add_statement: cst.SimpleStatementLine | None = None
-
         self.loop_state = LoopState()
         self.try_state = TryState()
 
-    @property
-    def infinite_loop(self) -> bool:
-        return self.loop_state.infinite_loop
-
-    @infinite_loop.setter
-    def infinite_loop(self, value: bool):
-        self.loop_state.infinite_loop = value
-
-    @property
-    def body_guaranteed_once(self) -> bool:
-        return self.loop_state.body_guaranteed_once
-
-    @body_guaranteed_once.setter
-    def body_guaranteed_once(self, value: bool):
-        self.loop_state.body_guaranteed_once = value
-
-    @property
-    def has_break(self) -> bool:
-        return self.loop_state.has_break
-
-    @has_break.setter
-    def has_break(self, value: bool):
-        self.loop_state.has_break = value
-
-    @property
-    def uncheckpointed_before_continue(self) -> set[Statement]:
-        return self.loop_state.uncheckpointed_before_continue
-
-    @uncheckpointed_before_continue.setter
-    def uncheckpointed_before_continue(self, value: set[Statement]):
-        self.loop_state.uncheckpointed_before_continue = value
-
-    @property
-    def uncheckpointed_before_break(self) -> set[Statement]:
-        return self.loop_state.uncheckpointed_before_break
-
-    @uncheckpointed_before_break.setter
-    def uncheckpointed_before_break(self, value: set[Statement]):
-        self.loop_state.uncheckpointed_before_break = value
-
     def checkpoint_statement(self) -> cst.SimpleStatementLine:
-        self.ensure_imported_library()
         return checkpoint_statement(self.library[0])
 
-    def visit_FunctionDef(self, node: cst.FunctionDef) -> None:
+    def visit_FunctionDef(self, node: cst.FunctionDef) -> bool:
         # don't lint functions whose bodies solely consist of pass or ellipsis
+        # @overload functions are also guaranteed to be empty
+        # we also ignore pytest fixtures
         if func_has_decorator(node, "overload", "fixture") or func_empty_body(node):
-            return
+            return False  # subnodes can be ignored
 
         self.save_state(
             node,
@@ -197,12 +263,15 @@ def visit_FunctionDef(self, node: cst.FunctionDef) -> None:
             )
         )
         if not self.async_function:
-            return
+            # only visit subnodes if there is an async function defined inside
+            # this should improve performance on codebases with many sync functions
+            return any(m.findall(node, m.FunctionDef(asynchronous=m.Asynchronous())))
 
         pos = self.get_metadata(PositionProvider, node).start
         self.uncheckpointed_statements = {
             Statement("function definition", pos.line, pos.column)
         }
+        return True
 
     def leave_FunctionDef(
         self, original_node: cst.FunctionDef, updated_node: cst.FunctionDef
@@ -248,7 +317,7 @@ def check_function_exit(
             # Add this as a node potentially needing checkpoints only if it
             # missing checkpoints solely depends on whether the artificial statement is
             # "real"
-            if len(self.uncheckpointed_statements) == 1:
+            if len(self.uncheckpointed_statements) == 1 and not self.noautofix:
                 self.loop_state.nodes_needing_checkpoints.append(original_node)
                 return False
 
@@ -274,38 +343,6 @@ def leave_Return(
         assert original_node.deep_equals(updated_node)
         return original_node
 
-    # TODO: generate an error in these two if transforming+visiting is done in a single
-    # pass and emit-error-on-transform can be enabled/disabled. The error can't be
-    # generated in the yield/return since it doesn't know if it will be autofixed.
-
-    # SimpleStatementSuite and multi-statement lines can probably be autofixed, but
-    # for now just don't insert checkpoints in the wrong place.
-    def leave_SimpleStatementSuite(
-        self,
-        original_node: cst.SimpleStatementSuite,
-        updated_node: cst.SimpleStatementSuite,
-    ) -> cst.SimpleStatementSuite:
-        self.add_statement = None
-        return updated_node
-
-    # insert checkpoint before yield with a flattensentinel, if indicated
-    def leave_SimpleStatementLine(
-        self,
-        original_node: cst.SimpleStatementLine,
-        updated_node: cst.SimpleStatementLine,
-    ) -> cst.SimpleStatementLine | cst.FlattenSentinel[cst.SimpleStatementLine]:
-        if self.add_statement is None:
-            return updated_node
-
-        # multiple statements on a single line is not handled
-        if len(updated_node.body) > 1:
-            self.add_statement = None
-            return updated_node
-
-        res = cst.FlattenSentinel([self.add_statement, updated_node])
-        self.add_statement = None
-        return res  # noqa: R504
-
     def error_91x(
         self,
         node: cst.Return | cst.FunctionDef | cst.Yield,
@@ -356,7 +393,7 @@ def leave_Yield(
             return updated_node
         self.has_yield = True
 
-        if self.check_function_exit(original_node):
+        if self.check_function_exit(original_node) and not self.noautofix:
             self.add_statement = self.checkpoint_statement()
 
         # mark as requiring checkpoint after
@@ -482,7 +519,7 @@ def visit_IfExp(self, node: cst.IfExp) -> bool:
         self.leave_If_body(node)
         _ = node.orelse.visit(self)
         self.leave_If(node, node)  # type: ignore
-        return False
+        return False  # libcst shouldn't visit subnodes again
 
     def visit_While(self, node: cst.While | cst.For):
         self.save_state(
@@ -491,7 +528,7 @@ def visit_While(self, node: cst.While | cst.For):
             copy=True,
         )
         self.loop_state = LoopState()
-        self.infinite_loop = self.body_guaranteed_once = False
+        self.loop_state.infinite_loop = self.loop_state.body_guaranteed_once = False
 
     visit_For = visit_While
 
@@ -505,10 +542,10 @@ def visit_While_test(self, node: cst.While):
         if (m.matches(node.test, m.Name("True"))) or (
             getattr(node.test, "evaluated_value", False)
         ):
-            self.infinite_loop = self.body_guaranteed_once = True
+            self.loop_state.infinite_loop = self.loop_state.body_guaranteed_once = True
 
     def visit_For_iter(self, node: cst.For):
-        self.body_guaranteed_once = iter_guaranteed_once_cst(node.iter)
+        self.loop_state.body_guaranteed_once = iter_guaranteed_once_cst(node.iter)
 
     def visit_While_body(self, node: cst.For | cst.While):
         if not self.async_function:
@@ -528,8 +565,8 @@ def visit_While_body(self, node: cst.For | cst.While):
         else:
             self.uncheckpointed_statements = {ARTIFICIAL_STATEMENT}
 
-        self.uncheckpointed_before_continue = set()
-        self.uncheckpointed_before_break = set()
+        self.loop_state.uncheckpointed_before_continue = set()
+        self.loop_state.uncheckpointed_before_break = set()
 
     visit_For_body = visit_While_body
 
@@ -545,7 +582,7 @@ def leave_While_body(self, node: cst.For | cst.While):
             for stmt in (
                 self.outer[node]["uncheckpointed_statements"]
                 | self.uncheckpointed_statements
-                | self.uncheckpointed_before_continue
+                | self.loop_state.uncheckpointed_before_continue
             ):
                 if stmt == ARTIFICIAL_STATEMENT:
                     continue
@@ -560,8 +597,8 @@ def leave_While_body(self, node: cst.For | cst.While):
         # replace artificial statements in else with prebody uncheckpointed statements
         # non-artificial stmts before continue/break/at body end will already be in them
         for stmts in (
-            self.uncheckpointed_before_continue,
-            self.uncheckpointed_before_break,
+            self.loop_state.uncheckpointed_before_continue,
+            self.loop_state.uncheckpointed_before_break,
             self.uncheckpointed_statements,
         ):
             if ARTIFICIAL_STATEMENT in stmts:
@@ -577,14 +614,14 @@ def leave_While_body(self, node: cst.For | cst.While):
             # loop body might execute fully before entering orelse
             # (current state of self.uncheckpointed_statements)
             # or not at all
-            if not self.body_guaranteed_once:
+            if not self.loop_state.body_guaranteed_once:
                 self.uncheckpointed_statements.update(
                     self.outer[node]["uncheckpointed_statements"]
                 )
             # or at a continue, unless it's an infinite loop
-            if not self.infinite_loop:
+            if not self.loop_state.infinite_loop:
                 self.uncheckpointed_statements.update(
-                    self.uncheckpointed_before_continue
+                    self.loop_state.uncheckpointed_before_continue
                 )
 
     leave_For_body = leave_While_body
@@ -594,13 +631,15 @@ def leave_While_orelse(self, node: cst.For | cst.While):
             return
         # if this is an infinite loop, with no break in it, don't raise
         # alarms about the state after it.
-        if self.infinite_loop and not self.has_break:
+        if self.loop_state.infinite_loop and not self.loop_state.has_break:
             self.uncheckpointed_statements = set()
         else:
             # We may exit from:
             # orelse (covering: no body, body until continue, and all body)
             # break
-            self.uncheckpointed_statements.update(self.uncheckpointed_before_break)
+            self.uncheckpointed_statements.update(
+                self.loop_state.uncheckpointed_before_break
+            )
 
         # reset break & continue in case of nested loops
         self.outer[node]["uncheckpointed_statements"] = self.uncheckpointed_statements
@@ -616,9 +655,8 @@ def leave_While(
         | cst.RemovalSentinel
     ):
         if self.loop_state.nodes_needing_checkpoints:
-            self.ensure_imported_library()
             transformer = InsertCheckpointsInLoopBody(
-                self.loop_state.nodes_needing_checkpoints, self.library[0]
+                self.loop_state.nodes_needing_checkpoints, self.library
             )
             # type of updated_node expanded to the return type
             updated_node = updated_node.visit(transformer)  # type: ignore
@@ -633,16 +671,20 @@ def leave_While(
     def visit_Continue(self, node: cst.Continue):
         if not self.async_function:
             return
-        self.uncheckpointed_before_continue.update(self.uncheckpointed_statements)
+        self.loop_state.uncheckpointed_before_continue.update(
+            self.uncheckpointed_statements
+        )
 
     def visit_Break(self, node: cst.Break):
-        self.has_break = True
+        self.loop_state.has_break = True
         if not self.async_function:
             return
-        self.uncheckpointed_before_break.update(self.uncheckpointed_statements)
+        self.loop_state.uncheckpointed_before_break.update(
+            self.uncheckpointed_statements
+        )
 
-    # first node in a condition is always evaluated, but may shortcut at any point
-    # after that so we track worst-case checkpoint (i.e. after yield)
+    # we visit BooleanOperation_left as usual, but ignore checkpoints in the
+    # right-hand side while still adding any yields in it.
     def visit_BooleanOperation_right(self, node: cst.BooleanOperation):
         if not self.async_function:
             return
@@ -718,7 +760,7 @@ def visit_CompFor(self, node: cst.CompFor):
         return False
 
     # We don't have any logic on if generators are guaranteed to unroll, so always
-    # ignore their content
+    # ignore their content by not visiting subnodes.
     def visit_GeneratorExp(self, node: cst.GeneratorExp):
         return False
 
@@ -735,15 +777,6 @@ def visit_Import(self, node: cst.Import):
                 assert isinstance(alias.name.value, str)
                 self.explicitly_imported_library[alias.name.value] = True
 
-    def ensure_imported_library(self) -> None:
-        """Mark library for import.
-
-        Check that the library we'd use to insert checkpoints
-        is imported - if not, mark it to be inserted later.
-        """
-        if not self.explicitly_imported_library[self.library[0]]:
-            self.add_import.add(self.library[0])
-
     def leave_Module(self, original_node: cst.Module, updated_node: cst.Module):
         """Add needed library import, if any, to the module."""
         if not self.add_import:
@@ -765,33 +798,3 @@ def leave_Module(self, original_node: cst.Module, updated_node: cst.Module):
         assert len(self.add_import) == 1
         new_body.insert(index, cst.parse_statement(f"import {self.library[0]}"))
         return updated_node.with_changes(body=new_body)
-
-
-# necessary as we don't know whether to insert checkpoints on the first pass of a loop
-# so we transform the loop body afterwards
-class InsertCheckpointsInLoopBody(cst.CSTTransformer):
-    def __init__(
-        self, nodes_needing_checkpoint: Sequence[cst.Yield | cst.Return], library: str
-    ):
-        super().__init__()
-        self.nodes_needing_checkpoint = nodes_needing_checkpoint
-        self.add_statement: cst.SimpleStatementLine | None = None
-        self.library = library
-
-    # insert checkpoint before yield with a flattensentinel, if indicated
-    # type checkers don't like going across classes, esp as the method accesses
-    # and modifies self.add_statement, but #YOLO
-    leave_SimpleStatementLine = Visitor91X.leave_SimpleStatementLine  # type: ignore
-
-    def leave_Yield(
-        self,
-        original_node: cst.Yield,
-        updated_node: cst.Yield,
-    ) -> cst.Yield:
-        # we need to check *original* node here, since updated node is a copy
-        # which loses identity equality
-        if original_node in self.nodes_needing_checkpoint:
-            self.add_statement = checkpoint_statement(self.library)
-        return updated_node
-
-    leave_Return = leave_Yield  # type: ignore
diff --git a/tests/autofix_files/trio100.py b/tests/autofix_files/trio100.py
index df7ea155..2027adce 100644
--- a/tests/autofix_files/trio100.py
+++ b/tests/autofix_files/trio100.py
@@ -1,4 +1,5 @@
 # type: ignore
+# AUTOFIX
 
 import trio
 
@@ -67,18 +68,3 @@ async def foo():
 
     async with random_ignored_library.fail_after(10):
         ...
-
-
-async def function_name2():
-    with (
-        open("") as _,
-        trio.fail_after(10),  # error: 8, "trio", "fail_after"
-    ):
-        ...
-
-    with (
-        trio.fail_after(5),  # error: 8, "trio", "fail_after"
-        open("") as _,
-        trio.move_on_after(5),  # error: 8, "trio", "move_on_after"
-    ):
-        ...
diff --git a/tests/autofix_files/trio100.py.diff b/tests/autofix_files/trio100.py.diff
index ea3f2a9a..1b9ed2c1 100644
--- a/tests/autofix_files/trio100.py.diff
+++ b/tests/autofix_files/trio100.py.diff
@@ -1,6 +1,6 @@
 ---
 +++
-@@ -2,24 +2,24 @@
+@@ -3,24 +3,24 @@
 
  import trio
 
@@ -38,7 +38,7 @@
 
      with trio.move_on_after(10):
          await trio.sleep(1)
-@@ -36,8 +36,8 @@
+@@ -37,8 +37,8 @@
      with open("filename") as _:
          ...
 
@@ -49,7 +49,7 @@
 
      send_channel, receive_channel = trio.open_memory_channel(0)
      async with trio.fail_after(10):
-@@ -48,22 +48,22 @@
+@@ -49,22 +49,22 @@
          async for _ in receive_channel:
              ...
 
diff --git a/tests/autofix_files/trio100_simple_autofix.py b/tests/autofix_files/trio100_simple_autofix.py
index 27dd18b8..7516fe64 100644
--- a/tests/autofix_files/trio100_simple_autofix.py
+++ b/tests/autofix_files/trio100_simple_autofix.py
@@ -1,3 +1,4 @@
+# AUTOFIX
 import trio
 
 # a
@@ -29,13 +30,6 @@
 # c
 # d
 
-# Doesn't autofix With's with multiple withitems
-with (
-    trio.move_on_after(10),  # error: 4, "trio", "move_on_after"
-    open("") as f,
-):
-    ...
-
 
 # multiline with, despite only being one statement
 # a
diff --git a/tests/autofix_files/trio100_simple_autofix.py.diff b/tests/autofix_files/trio100_simple_autofix.py.diff
index a8096ba0..ac5e82b7 100644
--- a/tests/autofix_files/trio100_simple_autofix.py.diff
+++ b/tests/autofix_files/trio100_simple_autofix.py.diff
@@ -1,6 +1,6 @@
 ---
 +++
-@@ -2,28 +2,29 @@
+@@ -3,50 +3,51 @@
 
  # a
  # b
@@ -45,7 +45,6 @@
  # fmt: on
  # c
  # d
-@@ -37,22 +38,22 @@
 
 
  # multiline with, despite only being one statement
diff --git a/tests/autofix_files/trio910.py b/tests/autofix_files/trio910.py
index 9a122423..a4bd9a32 100644
--- a/tests/autofix_files/trio910.py
+++ b/tests/autofix_files/trio910.py
@@ -1,3 +1,4 @@
+# AUTOFIX
 # mypy: disable-error-code="unreachable"
 import typing
 from typing import Any, overload
diff --git a/tests/autofix_files/trio910.py.diff b/tests/autofix_files/trio910.py.diff
index 167684f1..e79b955e 100644
--- a/tests/autofix_files/trio910.py.diff
+++ b/tests/autofix_files/trio910.py.diff
@@ -1,6 +1,6 @@
 ---
 +++
-@@ -44,12 +44,14 @@
+@@ -45,12 +45,14 @@
 
  async def foo1():  # error: 0, "exit", Statement("function definition", lineno)
      bar()
@@ -15,7 +15,7 @@
 
 
  async def foo_if_2():
-@@ -80,6 +82,7 @@
+@@ -81,6 +83,7 @@
 
  async def foo_ifexp_2():  # error: 0, "exit", Statement("function definition", lineno)
      print(_ if False and await foo() else await foo())
@@ -23,7 +23,7 @@
 
 
  # nested function definition
-@@ -88,6 +91,7 @@
+@@ -89,6 +92,7 @@
 
      async def foo_func_2():  # error: 4, "exit", Statement("function definition", lineno)
          bar()
@@ -31,7 +31,7 @@
 
 
  # we don't get a newline after the nested function definition before the checkpoint
-@@ -96,17 +100,21 @@
+@@ -97,17 +101,21 @@
  async def foo_func_3():  # error: 0, "exit", Statement("function definition", lineno)
      async def foo_func_4():
          await foo()
@@ -53,7 +53,7 @@
  # fmt: on
 
 
-@@ -143,11 +151,13 @@
+@@ -144,11 +152,13 @@
  async def foo_condition_2():  # error: 0, "exit", Statement("function definition", lineno)
      if False and await foo():
          ...
@@ -67,7 +67,7 @@
 
 
  async def foo_condition_4():  # safe
-@@ -169,6 +179,7 @@
+@@ -170,6 +180,7 @@
  async def foo_while_1():  # error: 0, "exit", Statement("function definition", lineno)
      while _:
          await foo()
@@ -75,7 +75,7 @@
 
 
  async def foo_while_2():  # now safe
-@@ -187,12 +198,14 @@
+@@ -188,12 +199,14 @@
  async def foo_while_4():  # error: 0, "exit", Statement("function definition", lineno)
      while False:
          await foo()
@@ -90,7 +90,7 @@
 
 
  async def foo_for_2():  # now safe
-@@ -215,6 +228,7 @@
+@@ -216,6 +229,7 @@
          break
      else:
          await foo()
@@ -98,7 +98,7 @@
 
 
  async def foo_while_break_3():  # error: 0, "exit", Statement("function definition", lineno)
-@@ -223,6 +237,7 @@
+@@ -224,6 +238,7 @@
          break
      else:
          ...
@@ -106,7 +106,7 @@
 
 
  async def foo_while_break_4():  # error: 0, "exit", Statement("function definition", lineno)
-@@ -230,6 +245,7 @@
+@@ -231,6 +246,7 @@
          break
      else:
          ...
@@ -114,7 +114,7 @@
 
 
  async def foo_while_continue_1():  # safe
-@@ -253,6 +269,7 @@
+@@ -254,6 +270,7 @@
          continue
      else:
          ...
@@ -122,7 +122,7 @@
 
 
  async def foo_while_continue_4():  # error: 0, "exit", Statement("function definition", lineno)
-@@ -260,6 +277,7 @@
+@@ -261,6 +278,7 @@
          continue
      else:
          ...
@@ -130,7 +130,7 @@
 
 
  async def foo_async_for_1():
-@@ -298,6 +316,7 @@
+@@ -299,6 +317,7 @@
          raise
      else:
          await foo()
@@ -138,7 +138,7 @@
 
 
  async def foo_try_2():  # safe
-@@ -348,6 +367,7 @@
+@@ -349,6 +368,7 @@
          pass
      else:
          pass
@@ -146,7 +146,7 @@
 
 
  async def foo_try_7():  # safe
-@@ -389,6 +409,7 @@
+@@ -390,6 +410,7 @@
          await trio.sleep(0)
      except:
          ...
@@ -154,7 +154,7 @@
 
 
  # safe
-@@ -416,16 +437,19 @@
+@@ -417,16 +438,19 @@
      except:
          ...
      finally:
@@ -174,7 +174,7 @@
          return  # error: 8, "return", Statement("function definition", lineno-2)
      await foo()
 
-@@ -434,6 +458,7 @@
+@@ -435,6 +459,7 @@
      if _:
          await foo()
          return  # safe
@@ -182,7 +182,7 @@
 
 
  # loop over non-empty static collection
-@@ -461,12 +486,14 @@
+@@ -462,12 +487,14 @@
  async def foo_range_4():  # error: 0, "exit", Statement("function definition", lineno)
      for i in range(10, 5):
          await foo()
@@ -197,7 +197,7 @@
 
 
  # https://github.com/Zac-HD/flake8-trio/issues/47
-@@ -550,6 +577,7 @@
+@@ -551,6 +578,7 @@
  # should error
  async def foo_comprehension_2():  # error: 0, "exit", Statement("function definition", lineno)
      [await foo() for x in range(10) if bar()]
diff --git a/tests/autofix_files/trio911.py b/tests/autofix_files/trio911.py
index e167b67f..a839c5fa 100644
--- a/tests/autofix_files/trio911.py
+++ b/tests/autofix_files/trio911.py
@@ -1,3 +1,4 @@
+# AUTOFIX
 from typing import Any
 
 import pytest
@@ -73,15 +74,6 @@ async def foo_async_with():
         yield
 
 
-# fmt: off
-async def foo_async_with_2():
-    # with'd expression evaluated before checkpoint
-    async with (yield):  # error: 16, "yield", Statement("function definition", lineno-2)
-        await trio.lowlevel.checkpoint()
-        yield
-# fmt: on
-
-
 async def foo_async_with_3():
     async with trio.fail_after(5):
         yield
@@ -90,11 +82,8 @@ async def foo_async_with_3():
 
 
 # async for
-async def foo_async_for():  # error: 0, "exit", Statement("yield", lineno+6)
-    async for i in (
-        yield  # error: 8, "yield", Statement("function definition", lineno-2)
-    ):
-        await trio.lowlevel.checkpoint()
+async def foo_async_for():  # error: 0, "exit", Statement("yield", lineno+4)
+    async for i in bar():
         yield  # safe
     else:
         yield  # safe
@@ -713,32 +702,6 @@ async def foo_boolops_1():  # error: 0, "exit", Stmt("yield", line+1)
     await trio.lowlevel.checkpoint()
 
 
-# may shortcut after any of the yields
-async def foo_boolops_2():  # error: 0, "exit", Stmt("yield", line+4) # error: 0, "exit", Stmt("yield", line+6)
-    await trio.lowlevel.checkpoint()
-    # known false positive - but chained yields in bool should be rare
-    _ = (
-        await foo()
-        and (yield)
-        and await foo()
-        and (yield)  # error: 13, "yield", Stmt("yield", line-2, 13)
-    )
-    await trio.lowlevel.checkpoint()
-
-
-# fmt: off
-async def foo_boolops_3():  # error: 0, "exit", Stmt("yield", line+1) # error: 0, "exit", Stmt("yield", line+4) # error: 0, "exit", Stmt("yield", line+5)
-    await trio.lowlevel.checkpoint()
-    _ = (await foo() or (yield) or await foo()) or (
-        ...
-        or (
-            (yield)  # error: 13, "yield", Stmt("yield", line-3)
-            and (yield))  # error: 17, "yield", Stmt("yield", line-1)
-    )
-    await trio.lowlevel.checkpoint()
-# fmt: on
-
-
 # loop over non-empty static collection
 async def foo_loop_static():
     # break/else behaviour on guaranteed body execution
diff --git a/tests/autofix_files/trio911.py.diff b/tests/autofix_files/trio911.py.diff
index c9b54841..d9c63d51 100644
--- a/tests/autofix_files/trio911.py.diff
+++ b/tests/autofix_files/trio911.py.diff
@@ -1,6 +1,6 @@
 ---
 +++
-@@ -23,7 +23,9 @@
+@@ -24,7 +24,9 @@
 
 
  async def foo_yield_2():
@@ -10,7 +10,7 @@
      yield  # error: 4, "yield", Statement("yield", lineno-1)
      await foo()
 
-@@ -31,22 +33,29 @@
+@@ -32,22 +34,29 @@
  async def foo_yield_3():  # error: 0, "exit", Statement("yield", lineno+2)
      await foo()
      yield
@@ -41,14 +41,6 @@
 
 
 @@ -68,6 +77,7 @@
- async def foo_async_with_2():
-     # with'd expression evaluated before checkpoint
-     async with (yield):  # error: 16, "yield", Statement("function definition", lineno-2)
-+        await trio.lowlevel.checkpoint()
-         yield
- # fmt: on
-
-@@ -75,6 +85,7 @@
  async def foo_async_with_3():
      async with trio.fail_after(5):
          yield
@@ -56,11 +48,7 @@
          yield  # error: 8, "yield", Statement("yield", lineno-1)
 
 
-@@ -83,9 +94,11 @@
-     async for i in (
-         yield  # error: 8, "yield", Statement("function definition", lineno-2)
-     ):
-+        await trio.lowlevel.checkpoint()
+@@ -77,6 +87,7 @@
          yield  # safe
      else:
          yield  # safe
@@ -68,7 +56,7 @@
 
 
  # await anext(iter) is not called on break
-@@ -94,6 +107,7 @@
+@@ -85,6 +96,7 @@
          yield
          if ...:
              break
@@ -76,7 +64,7 @@
 
 
  async def foo_async_for_3():  # safe
-@@ -111,13 +125,16 @@
+@@ -102,13 +114,16 @@
  async def foo_for():  # error: 0, "exit", Statement("yield", lineno+3)
      await foo()
      for i in "":
@@ -93,7 +81,7 @@
 
 
  # while
-@@ -130,13 +147,16 @@
+@@ -121,13 +136,16 @@
      else:
          await foo()  # will always run
      yield  # safe
@@ -110,7 +98,7 @@
 
 
  # no checkpoint after yield if else is entered
-@@ -145,39 +165,52 @@
+@@ -136,39 +154,52 @@
          await foo()
          yield
      else:
@@ -163,7 +151,7 @@
 
      await foo()
 
-@@ -187,16 +220,19 @@
+@@ -178,16 +209,19 @@
  async def foo_while_continue_1():  # error: 0, "exit", Statement("yield", lineno+3)
      await foo()
      while foo():
@@ -183,7 +171,7 @@
          yield  # error: 8, "yield", Statement("yield", lineno)
          if foo():
              continue
-@@ -206,6 +242,7 @@
+@@ -197,6 +231,7 @@
          while foo():
              yield  # safe
              await foo()
@@ -191,7 +179,7 @@
 
 
  # --- while + break ---
-@@ -216,7 +253,9 @@
+@@ -207,7 +242,9 @@
              break
      else:
          await foo()
@@ -201,7 +189,7 @@
 
 
  # no checkpoint on break
-@@ -227,6 +266,7 @@
+@@ -218,6 +255,7 @@
          if ...:
              break
          await foo()
@@ -209,7 +197,7 @@
 
 
  # guaranteed if else and break
-@@ -238,6 +278,7 @@
+@@ -229,6 +267,7 @@
      else:
          await foo()  # runs if 0-iter
      yield  # safe
@@ -217,7 +205,7 @@
 
 
  # break at non-guaranteed checkpoint
-@@ -248,7 +289,9 @@
+@@ -239,7 +278,9 @@
          await foo()  # might not run
      else:
          await foo()  # might not run
@@ -227,7 +215,7 @@
 
 
  # check break is reset on nested
-@@ -264,7 +307,9 @@
+@@ -255,7 +296,9 @@
              await foo()
          yield  # safe
          await foo()
@@ -237,7 +225,7 @@
 
 
  # check multiple breaks
-@@ -279,7 +324,9 @@
+@@ -270,7 +313,9 @@
          await foo()
          if ...:
              break
@@ -247,7 +235,7 @@
 
 
  async def foo_while_break_7():  # error: 0, "exit", Statement("function definition", lineno)# error: 0, "exit", Statement("yield", lineno+5)
-@@ -289,6 +336,7 @@
+@@ -280,6 +325,7 @@
              break
          yield
          break
@@ -255,7 +243,7 @@
 
 
  async def foo_while_endless_1():
-@@ -301,6 +349,7 @@
+@@ -292,6 +338,7 @@
      while foo():
          await foo()
          yield
@@ -263,7 +251,7 @@
 
 
  async def foo_while_endless_3():
-@@ -322,9 +371,11 @@
+@@ -313,9 +360,11 @@
  # try
  async def foo_try_1():  # error: 0, "exit", Statement("function definition", lineno) # error: 0, "exit", Statement("yield", lineno+2)
      try:
@@ -275,7 +263,7 @@
 
 
  # no checkpoint after yield in ValueError
-@@ -332,12 +383,14 @@
+@@ -323,12 +372,14 @@
      try:
          await foo()
      except ValueError:
@@ -290,7 +278,7 @@
 
 
  async def foo_try_3():  # error: 0, "exit", Statement("yield", lineno+6)
-@@ -346,13 +399,16 @@
+@@ -337,13 +388,16 @@
      except:
          await foo()
      else:
@@ -307,7 +295,7 @@
          yield  # error: 8, "yield", Statement("function definition", lineno-4)
      finally:
          await foo()
-@@ -362,6 +418,7 @@
+@@ -353,6 +407,7 @@
      try:
          await foo()
      finally:
@@ -315,7 +303,7 @@
          # try might crash before checkpoint
          yield  # error: 8, "yield", Statement("function definition", lineno-5)
          await foo()
-@@ -372,7 +429,9 @@
+@@ -363,7 +418,9 @@
          await foo()
      except ValueError:
          pass
@@ -325,7 +313,7 @@
 
 
  async def foo_try_7():  # error: 0, "exit", Statement("yield", lineno+17)
-@@ -385,6 +444,7 @@
+@@ -376,6 +433,7 @@
          yield
          await foo()
      except SyntaxError:
@@ -333,7 +321,7 @@
          yield  # error: 8, "yield", Statement("yield", lineno-7)
          await foo()
      finally:
-@@ -393,6 +453,7 @@
+@@ -384,6 +442,7 @@
      # by any of the excepts, jumping straight to the finally.
      # Then the error will be propagated upwards
      yield  # safe
@@ -341,7 +329,7 @@
 
 
  ## safe only if (try or else) and all except bodies either await or raise
-@@ -408,6 +469,7 @@
+@@ -399,6 +458,7 @@
          raise
      else:
          await foo()
@@ -349,7 +337,7 @@
 
 
  # no checkpoint after yield in else
-@@ -418,6 +480,7 @@
+@@ -409,6 +469,7 @@
          await foo()
      else:
          yield
@@ -357,7 +345,7 @@
 
 
  # bare except means we'll jump to finally after full execution of either try or the except
-@@ -448,6 +511,7 @@
+@@ -439,6 +500,7 @@
      except ValueError:
          await foo()
      finally:
@@ -365,7 +353,7 @@
          yield  # error: 8, "yield", Statement("function definition", lineno-6)
          await foo()
 
-@@ -456,6 +520,7 @@
+@@ -447,6 +509,7 @@
      try:
          await foo()
      finally:
@@ -373,7 +361,7 @@
          # try might crash before checkpoint
          yield  # error: 8, "yield", Statement("function definition", lineno-5)
          await foo()
-@@ -464,9 +529,11 @@
+@@ -455,9 +518,11 @@
  # if
  async def foo_if_1():
      if ...:
@@ -385,7 +373,7 @@
          yield  # error: 8, "yield", Statement("function definition", lineno-5)
          await foo()
 
-@@ -477,7 +544,9 @@
+@@ -468,7 +533,9 @@
          ...
      else:
          yield
@@ -395,7 +383,7 @@
 
 
  async def foo_if_3():  # error: 0, "exit", Statement("yield", lineno+6)
-@@ -486,7 +555,9 @@
+@@ -477,7 +544,9 @@
          yield
      else:
          ...
@@ -405,7 +393,7 @@
 
 
  async def foo_if_4():  # error: 0, "exit", Statement("yield", lineno+7)
-@@ -496,7 +567,9 @@
+@@ -487,7 +556,9 @@
          await foo()
      else:
          ...
@@ -415,7 +403,7 @@
 
 
  async def foo_if_5():  # error: 0, "exit", Statement("yield", lineno+8)
-@@ -507,7 +580,9 @@
+@@ -498,7 +569,9 @@
      else:
          yield
          ...
@@ -425,7 +413,7 @@
 
 
  async def foo_if_6():  # error: 0, "exit", Statement("yield", lineno+8)
-@@ -518,7 +593,9 @@
+@@ -509,7 +582,9 @@
          yield
          await foo()
          ...
@@ -435,7 +423,7 @@
 
 
  async def foo_if_7():  # error: 0, "exit", Statement("function definition", lineno)
-@@ -526,6 +603,7 @@
+@@ -517,6 +592,7 @@
          await foo()
          yield
          await foo()
@@ -443,7 +431,7 @@
 
 
  async def foo_if_8():  # error: 0, "exit", Statement("function definition", lineno)
-@@ -535,21 +613,25 @@
+@@ -526,21 +602,25 @@
          await foo()
          yield
          await foo()
@@ -469,7 +457,7 @@
 
 
  # normal function
-@@ -594,7 +676,9 @@
+@@ -585,7 +665,9 @@
      await foo()
 
      async def foo_func_2():  # error: 4, "exit", Statement("yield", lineno+1)
@@ -479,7 +467,7 @@
 
 
  # autofix doesn't insert newline after nested function def and before checkpoint
-@@ -606,6 +690,7 @@
+@@ -597,6 +679,7 @@
 
      async def foo_func_4():
          await foo()
@@ -487,7 +475,7 @@
 
 
  async def foo_func_5():  # error: 0, "exit", Statement("yield", lineno+2)
-@@ -618,16 +703,19 @@
+@@ -609,12 +692,14 @@
          async def foo_func_7():
              await foo()
              ...
@@ -501,33 +489,8 @@
 +    await trio.lowlevel.checkpoint()
 
 
- # may shortcut after any of the yields
- async def foo_boolops_2():  # error: 0, "exit", Stmt("yield", line+4) # error: 0, "exit", Stmt("yield", line+6)
-+    await trio.lowlevel.checkpoint()
-     # known false positive - but chained yields in bool should be rare
-     _ = (
-         await foo()
-@@ -635,16 +723,19 @@
-         and await foo()
-         and (yield)  # error: 13, "yield", Stmt("yield", line-2, 13)
-     )
-+    await trio.lowlevel.checkpoint()
-
-
- # fmt: off
- async def foo_boolops_3():  # error: 0, "exit", Stmt("yield", line+1) # error: 0, "exit", Stmt("yield", line+4) # error: 0, "exit", Stmt("yield", line+5)
-+    await trio.lowlevel.checkpoint()
-     _ = (await foo() or (yield) or await foo()) or (
-         ...
-         or (
-             (yield)  # error: 13, "yield", Stmt("yield", line-3)
-             and (yield))  # error: 17, "yield", Stmt("yield", line-1)
-     )
-+    await trio.lowlevel.checkpoint()
- # fmt: on
-
-
-@@ -672,6 +763,7 @@
+ # loop over non-empty static collection
+@@ -641,6 +726,7 @@
          if ...:
              continue
          await foo()
@@ -535,7 +498,7 @@
      yield  # error: 4, "yield", Stmt("yield", line-7)
 
      # continue/else
-@@ -680,6 +772,7 @@
+@@ -649,6 +735,7 @@
              continue
          await foo()
      else:
@@ -543,7 +506,7 @@
          yield  # error: 8, "yield", Stmt("yield", line-8)
      await foo()
      yield
-@@ -724,6 +817,7 @@
+@@ -693,6 +780,7 @@
 
      for _ in ():
          await foo()
@@ -551,7 +514,7 @@
      yield  # error: 4, "yield", Stmt("yield", line-4)
 
      for _ in {1: 2, 3: 4}:
-@@ -732,14 +826,17 @@
+@@ -701,14 +789,17 @@
 
      for _ in "   ".strip():
          await foo()
@@ -569,7 +532,7 @@
      yield  # error: 4, "yield", Stmt("yield", line-4)
 
      for _ in (*(1, 2),):
-@@ -748,10 +845,12 @@
+@@ -717,10 +808,12 @@
 
      for _ in {**{}}:
          await foo()
@@ -582,7 +545,7 @@
      yield  # error: 4, "yield", Stmt("yield", line-4)
 
      for _ in {**{1: 2}}:
-@@ -777,31 +876,38 @@
+@@ -746,31 +839,38 @@
 
      for _ in {}:
          await foo()
@@ -621,7 +584,7 @@
      yield  # error: 4, "yield", Stmt("yield", line-4)
 
      # while
-@@ -815,6 +921,7 @@
+@@ -784,6 +884,7 @@
          if ...:
              break
          await foo()
@@ -629,7 +592,7 @@
      yield  # error: 4, "yield", Stmt("yield", line-6)
 
      while True:
-@@ -827,6 +934,7 @@
+@@ -796,6 +897,7 @@
 
      while False:
          await foo()  # type: ignore[unreachable]
@@ -637,7 +600,7 @@
      yield  # error: 4, "yield", Stmt("yield", line-4)
 
      while "hello":
-@@ -836,11 +944,13 @@
+@@ -805,11 +907,13 @@
      # false positive on containers
      while [1, 2]:
          await foo()
@@ -651,7 +614,7 @@
      yield  # error: 4, "yield", Stmt("yield", line-5)
 
      # range with constant arguments also handled, see more extensive tests in 910
-@@ -858,10 +968,12 @@
+@@ -827,10 +931,12 @@
 
      for i in range(1 + 1):  # not handled
          await foo()
@@ -664,7 +627,7 @@
      yield  # error: 4, "yield", Stmt("yield", line-4)
 
      for i in range(+3):
-@@ -870,6 +982,7 @@
+@@ -839,6 +945,7 @@
 
      for i in range(-3.5):  # type: ignore
          await foo()
@@ -672,7 +635,7 @@
      yield  # error: 4, "yield", Stmt("yield", line-4)
 
      # duplicated from 910 to have all range tests in one place
-@@ -893,20 +1006,24 @@
+@@ -862,20 +969,24 @@
 
      for i in range(10, 5):
          await foo()
@@ -697,7 +660,7 @@
      yield  # error: 4, "yield", Stmt("yield", line-5)
 
      await foo()
-@@ -930,6 +1047,7 @@
+@@ -899,6 +1010,7 @@
 
      # guaranteed iteration and await in value, but test is not guaranteed
      [await foo() for x in range(10) if bar()]
@@ -705,7 +668,7 @@
      yield  # error: 4, "yield", Stmt("yield", line-4)
 
      # guaranteed iteration and await in value
-@@ -938,6 +1056,7 @@
+@@ -907,6 +1019,7 @@
 
      # not guaranteed to iter
      [await foo() for x in bar()]
@@ -713,7 +676,7 @@
      yield  # error: 4, "yield", Stmt("yield", line-4)
 
      # await statement in loop expression
-@@ -949,10 +1068,12 @@
+@@ -918,10 +1031,12 @@
      yield  # safe
 
      {await foo() for x in bar()}
@@ -726,7 +689,7 @@
      yield  # error: 4, "yield", Stmt("yield", line-4)
 
      # other than `await` can be in both key&val
-@@ -964,9 +1085,11 @@
+@@ -933,9 +1048,11 @@
 
      # generator expressions are never treated as safe
      (await foo() for x in range(10))
@@ -738,7 +701,7 @@
      yield  # error: 4, "yield", Stmt("yield", line-3)
 
      # async for always safe
-@@ -979,27 +1102,33 @@
+@@ -948,27 +1065,33 @@
 
      # other than in generator expression
      (... async for x in bar())
@@ -772,7 +735,7 @@
      yield  # error: 4, "yield", Stmt("yield", line-2)
 
      # multiple ifs
-@@ -1007,6 +1136,7 @@
+@@ -976,6 +1099,7 @@
      yield
 
      [... for x in range(10) for y in bar() if await foo() if await foo()]
diff --git a/tests/autofix_files/trio91x_autofix.py b/tests/autofix_files/trio91x_autofix.py
index cb4868ba..a0bc3d06 100644
--- a/tests/autofix_files/trio91x_autofix.py
+++ b/tests/autofix_files/trio91x_autofix.py
@@ -1,3 +1,4 @@
+# AUTOFIX
 from __future__ import annotations
 
 """Docstring for file
@@ -107,25 +108,21 @@ async def bar():
             await foo()
 
 
-# not handled, but at least doesn't insert an unnecessary checkpoint
-async def foo_singleline():
-    await foo()
-    # fmt: off
-    yield; yield  # TRIO911: 11, "yield", Statement("yield", lineno, 4)
-    # fmt: on
-    await foo()
-
-
-# not autofixed
-async def foo_singleline2():
-    # fmt: off
-    yield; await foo()  # TRIO911: 4, "yield", Statement("function definition", lineno-2)
-    # fmt: on
+# Code coverage: visitors run when inside a sync function that has an async function.
+# When sync funcs don't contain an async func the body is not visited.
+def sync_func():
+    async def async_func():
+        ...
 
-
-# not autofixed
-async def foo_singleline3():
-    # fmt: off
-    if ...: yield  # TRIO911: 12, "yield", Statement("function definition", lineno-2)
-    # fmt: on
-    await foo()
+    try:
+        ...
+    except:
+        ...
+    if ... and ...:
+        ...
+    while ...:
+        if ...:
+            continue
+        break
+    [... for i in range(5)]
+    return
diff --git a/tests/autofix_files/trio91x_autofix.py.diff b/tests/autofix_files/trio91x_autofix.py.diff
index 65d90259..2ab4724d 100644
--- a/tests/autofix_files/trio91x_autofix.py.diff
+++ b/tests/autofix_files/trio91x_autofix.py.diff
@@ -1,6 +1,6 @@
 ---
 +++
-@@ -8,6 +8,7 @@
+@@ -9,6 +9,7 @@
  # ARG --enable-visitor-codes-regex=(TRIO910)|(TRIO911)
 
  from typing import Any
@@ -8,7 +8,7 @@
 
 
  def bar() -> Any:
-@@ -20,30 +21,38 @@
+@@ -21,30 +22,38 @@
 
  async def foo1():  # TRIO910: 0, "exit", Statement("function definition", lineno)
      bar()
@@ -47,7 +47,7 @@
          yield  # TRIO911: 8, "yield", Statement("yield", lineno)
 
 
-@@ -66,8 +75,10 @@
+@@ -67,8 +76,10 @@
  async def foo_while4():
      while True:
          if ...:
@@ -58,7 +58,7 @@
              yield  # TRIO911: 12, "yield", Statement("yield", lineno)  # TRIO911: 12, "yield", Statement("yield", lineno-2)  # TRIO911: 12, "yield", Statement("function definition", lineno-5) # TRIO911: 12, "yield", Statement("yield", lineno-2)
              # this warns about the yield on lineno-2 twice, since it can arrive here from it in two different ways
 
-@@ -75,15 +86,19 @@
+@@ -76,15 +87,19 @@
  # check state management of nested loops
  async def foo_nested_while():
      while True:
diff --git a/tests/eval_files/trio100.py b/tests/eval_files/trio100.py
index b63cf5ee..d22fc9c7 100644
--- a/tests/eval_files/trio100.py
+++ b/tests/eval_files/trio100.py
@@ -1,4 +1,5 @@
 # type: ignore
+# AUTOFIX
 
 import trio
 
@@ -67,18 +68,3 @@ async def foo():
 
     async with random_ignored_library.fail_after(10):
         ...
-
-
-async def function_name2():
-    with (
-        open("") as _,
-        trio.fail_after(10),  # error: 8, "trio", "fail_after"
-    ):
-        ...
-
-    with (
-        trio.fail_after(5),  # error: 8, "trio", "fail_after"
-        open("") as _,
-        trio.move_on_after(5),  # error: 8, "trio", "move_on_after"
-    ):
-        ...
diff --git a/tests/eval_files/trio100_noautofix.py b/tests/eval_files/trio100_noautofix.py
new file mode 100644
index 00000000..f16d77b1
--- /dev/null
+++ b/tests/eval_files/trio100_noautofix.py
@@ -0,0 +1,24 @@
+import trio
+
+
+# Doesn't autofix With's with multiple withitems
+async def function_name2():
+    with (
+        open("") as _,
+        trio.fail_after(10),  # error: 8, "trio", "fail_after"
+    ):
+        ...
+
+    with (
+        trio.fail_after(5),  # error: 8, "trio", "fail_after"
+        open("") as _,
+        trio.move_on_after(5),  # error: 8, "trio", "move_on_after"
+    ):
+        ...
+
+
+with (
+    trio.move_on_after(10),  # error: 4, "trio", "move_on_after"
+    open("") as f,
+):
+    ...
diff --git a/tests/eval_files/trio100_simple_autofix.py b/tests/eval_files/trio100_simple_autofix.py
index 46655c3d..2ddc609d 100644
--- a/tests/eval_files/trio100_simple_autofix.py
+++ b/tests/eval_files/trio100_simple_autofix.py
@@ -1,3 +1,4 @@
+# AUTOFIX
 import trio
 
 # a
@@ -28,13 +29,6 @@
 # c
 # d
 
-# Doesn't autofix With's with multiple withitems
-with (
-    trio.move_on_after(10),  # error: 4, "trio", "move_on_after"
-    open("") as f,
-):
-    ...
-
 
 # multiline with, despite only being one statement
 with (  # a
diff --git a/tests/eval_files/trio910.py b/tests/eval_files/trio910.py
index 10c8126d..32eed8ad 100644
--- a/tests/eval_files/trio910.py
+++ b/tests/eval_files/trio910.py
@@ -1,3 +1,4 @@
+# AUTOFIX
 # mypy: disable-error-code="unreachable"
 import typing
 from typing import Any, overload
diff --git a/tests/eval_files/trio911.py b/tests/eval_files/trio911.py
index 56a33ccd..746c5562 100644
--- a/tests/eval_files/trio911.py
+++ b/tests/eval_files/trio911.py
@@ -1,3 +1,4 @@
+# AUTOFIX
 from typing import Any
 
 import pytest
@@ -64,14 +65,6 @@ async def foo_async_with():
         yield
 
 
-# fmt: off
-async def foo_async_with_2():
-    # with'd expression evaluated before checkpoint
-    async with (yield):  # error: 16, "yield", Statement("function definition", lineno-2)
-        yield
-# fmt: on
-
-
 async def foo_async_with_3():
     async with trio.fail_after(5):
         yield
@@ -79,10 +72,8 @@ async def foo_async_with_3():
 
 
 # async for
-async def foo_async_for():  # error: 0, "exit", Statement("yield", lineno+6)
-    async for i in (
-        yield  # error: 8, "yield", Statement("function definition", lineno-2)
-    ):
+async def foo_async_for():  # error: 0, "exit", Statement("yield", lineno+4)
+    async for i in bar():
         yield  # safe
     else:
         yield  # safe
@@ -626,28 +617,6 @@ async def foo_boolops_1():  # error: 0, "exit", Stmt("yield", line+1)
     _ = await foo() and (yield) and await foo()
 
 
-# may shortcut after any of the yields
-async def foo_boolops_2():  # error: 0, "exit", Stmt("yield", line+4) # error: 0, "exit", Stmt("yield", line+6)
-    # known false positive - but chained yields in bool should be rare
-    _ = (
-        await foo()
-        and (yield)
-        and await foo()
-        and (yield)  # error: 13, "yield", Stmt("yield", line-2, 13)
-    )
-
-
-# fmt: off
-async def foo_boolops_3():  # error: 0, "exit", Stmt("yield", line+1) # error: 0, "exit", Stmt("yield", line+4) # error: 0, "exit", Stmt("yield", line+5)
-    _ = (await foo() or (yield) or await foo()) or (
-        ...
-        or (
-            (yield)  # error: 13, "yield", Stmt("yield", line-3)
-            and (yield))  # error: 17, "yield", Stmt("yield", line-1)
-    )
-# fmt: on
-
-
 # loop over non-empty static collection
 async def foo_loop_static():
     # break/else behaviour on guaranteed body execution
diff --git a/tests/eval_files/trio91x_autofix.py b/tests/eval_files/trio91x_autofix.py
index c1f09607..ca46596f 100644
--- a/tests/eval_files/trio91x_autofix.py
+++ b/tests/eval_files/trio91x_autofix.py
@@ -1,3 +1,4 @@
+# AUTOFIX
 from __future__ import annotations
 
 """Docstring for file
@@ -92,25 +93,21 @@ async def bar():
             await foo()
 
 
-# not handled, but at least doesn't insert an unnecessary checkpoint
-async def foo_singleline():
-    await foo()
-    # fmt: off
-    yield; yield  # TRIO911: 11, "yield", Statement("yield", lineno, 4)
-    # fmt: on
-    await foo()
-
-
-# not autofixed
-async def foo_singleline2():
-    # fmt: off
-    yield; await foo()  # TRIO911: 4, "yield", Statement("function definition", lineno-2)
-    # fmt: on
+# Code coverage: visitors run when inside a sync function that has an async function.
+# When sync funcs don't contain an async func the body is not visited.
+def sync_func():
+    async def async_func():
+        ...
 
-
-# not autofixed
-async def foo_singleline3():
-    # fmt: off
-    if ...: yield  # TRIO911: 12, "yield", Statement("function definition", lineno-2)
-    # fmt: on
-    await foo()
+    try:
+        ...
+    except:
+        ...
+    if ... and ...:
+        ...
+    while ...:
+        if ...:
+            continue
+        break
+    [... for i in range(5)]
+    return
diff --git a/tests/eval_files/trio91x_noautofix.py b/tests/eval_files/trio91x_noautofix.py
new file mode 100644
index 00000000..1c7eee16
--- /dev/null
+++ b/tests/eval_files/trio91x_noautofix.py
@@ -0,0 +1,71 @@
+# ARG --enable-visitor-codes-regex=(TRIO910)|(TRIO911)
+from typing import Any
+
+
+async def foo() -> Any:
+    await foo()
+
+
+# not handled, but at least doesn't insert an unnecessary checkpoint
+async def foo_singleline():
+    await foo()
+    # fmt: off
+    yield; yield  # TRIO911: 11, "yield", Statement("yield", lineno, 4)
+    # fmt: on
+    await foo()
+
+
+# not autofixed
+async def foo_singleline2():
+    # fmt: off
+    yield; await foo()  # TRIO911: 4, "yield", Statement("function definition", lineno-2)
+    # fmt: on
+
+
+# not autofixed
+async def foo_singleline3():
+    # fmt: off
+    if ...: yield  # TRIO911: 12, "yield", Statement("function definition", lineno-2)
+    # fmt: on
+    await foo()
+
+
+# fmt: off
+async def foo_async_with_2():
+    # with'd expression evaluated before checkpoint
+    async with (yield):  # TRIO911: 16, "yield", Statement("function definition", lineno-2)
+        yield
+# fmt: on
+
+# fmt: off
+async def foo_boolops_3():
+    _ = (await foo() or (yield) or await foo()) or (
+        ...
+        or (
+            (yield)  # TRIO911: 13, "yield", Stmt("yield", line-3)
+            and (yield))  # TRIO911: 17, "yield", Stmt("yield", line-1)
+    )
+    await foo()
+# fmt: on
+
+
+async def foo_async_for():
+    async for i in (
+        yield  # TRIO911: 8, "yield", Statement("function definition", lineno-2)
+    ):
+        yield  # safe
+    else:
+        yield  # safe
+    await foo()
+
+
+# may shortcut after any of the yields
+async def foo_boolops_2():
+    # known false positive - but chained yields in bool should be rare
+    _ = (
+        await foo()
+        and (yield)
+        and await foo()
+        and (yield)  # TRIO911: 13, "yield", Stmt("yield", line-2, 13)
+    )
+    await foo()
diff --git a/tests/test_flake8_trio.py b/tests/test_flake8_trio.py
index 94aca2ff..35e51ecf 100644
--- a/tests/test_flake8_trio.py
+++ b/tests/test_flake8_trio.py
@@ -32,14 +32,13 @@
 
     from flake8_trio.visitors.flake8triovisitor import Flake8TrioVisitor
 
+AUTOFIX_DIR = Path(__file__).parent / "autofix_files"
 
 test_files: list[tuple[str, Path]] = sorted(
     (f.stem.upper(), f) for f in (Path(__file__).parent / "eval_files").iterdir()
 )
 autofix_files: dict[str, Path] = {
-    f.stem.upper(): f
-    for f in (Path(__file__).parent / "autofix_files").iterdir()
-    if f.suffix == ".py"
+    f.stem.upper(): f for f in AUTOFIX_DIR.iterdir() if f.suffix == ".py"
 }
 # check that there's an eval file for each autofix file
 assert set(autofix_files.keys()) - {f[0] for f in test_files} == set()
@@ -110,18 +109,22 @@ def check_autofix(
     generate_autofix: bool,
     anyio: bool = False,
 ):
-    if test not in autofix_files:
-        return
     # the source code after it's been visited by current transformers
     visited_code = plugin.module.code
+
+    if "# AUTOFIX" not in unfixed_code:
+        assert unfixed_code == visited_code
+        return
+
     # the full generated source code, saved from a previous run
+    if test not in autofix_files:
+        autofix_files[test] = AUTOFIX_DIR / (test.lower() + ".py")
+        autofix_files[test].write_text("")
     previous_autofixed = autofix_files[test].read_text()
 
     # file contains a previous diff showing what's added/removed by the autofixer
     # i.e. a diff between "eval_files/{test}.py" and "autofix_files/{test}.py"
-    autofix_diff_file = (
-        Path(__file__).parent / "autofix_files" / f"{test.lower()}.py.diff"
-    )
+    autofix_diff_file = AUTOFIX_DIR / f"{test.lower()}.py.diff"
     if not autofix_diff_file.exists():
         assert generate_autofix, "autofix diff file doesn't exist"
         # if generate_autofix is set, the diff content isn't used and the file
@@ -219,6 +222,26 @@ def test_eval_anyio(test: str, path: Path, generate_autofix: bool):
     check_autofix(test, plugin, content, generate_autofix, anyio=True)
 
 
+# check that autofixed files raise no errors and doesn't get autofixed (again)
+@pytest.mark.parametrize("test", autofix_files)
+def test_autofix(test: str):
+    content = autofix_files[test].read_text()
+    if "# NOTRIO" in content:
+        pytest.skip("file marked with NOTRIO")
+
+    _, parsed_args = _parse_eval_file(test, content)
+    parsed_args.append("--autofix")
+
+    plugin = Plugin.from_source(content)
+    # not passing any expected errors
+    _ = assert_expected_errors(plugin, args=parsed_args)
+
+    diff = diff_strings(plugin.module.code, content)
+    if diff:
+        print(diff)
+    assert plugin.module.code == content, "autofixed file changed when autofixed again"
+
+
 def _parse_eval_file(test: str, content: str) -> tuple[list[Error], list[str]]:
     # version check
     check_version(test)
@@ -298,6 +321,7 @@ def _parse_eval_file(test: str, content: str) -> tuple[list[Error], list[str]]:
                 )
                 raise ParseError(msg) from e
 
+    assert visitor_codes_regex, "no visitors enabled"
     for error in expected:
         assert re.match(
             visitor_codes_regex, error.code