drop python3.9, add+fix testing for 3.14

.github/workflows/ci.yml

@@ -13,9 +13,9 @@ jobs:
     pyright:
         runs-on: ubuntu-latest
         steps:
-            - uses: actions/checkout@v4
+            - uses: actions/checkout@v5
             - name: Set up Python
-              uses: actions/setup-python@v5
+              uses: actions/setup-python@v6
               with:
                   cache: pip
             - name: Install typing dependencies
@@ -30,14 +30,15 @@ jobs:
         runs-on: ubuntu-latest
         strategy:
             matrix:
-                python-version: ['3.9', '3.10', '3.11', '3.12', '3.13']
+                python-version: ['3.10', '3.11', '3.12', '3.13', '3.14']
             fail-fast: false
         steps:
-            - uses: actions/checkout@v4
+            - uses: actions/checkout@v5
             - name: Set up Python ${{ matrix.python-version }}
-              uses: actions/setup-python@v5
+              uses: actions/setup-python@v6
               with:
                   python-version: ${{ matrix.python-version }}
+                  allow-prereleases: true
             - name: Install dependencies
               run: python -m pip install --upgrade pip setuptools tox
             - name: Run tests with flake8
@@ -50,11 +51,11 @@ jobs:
         strategy:
             fail-fast: false
         steps:
-            - uses: actions/checkout@v4
-            - name: Set up Python 3.13
-              uses: actions/setup-python@v5
+            - uses: actions/checkout@v5
+            - name: Set up Python 3.14
+              uses: actions/setup-python@v6
               with:
-                  python-version: 3.13
+                  python-version: 3.14
             - name: Install dependencies
               run: |
                   python -m pip install --upgrade pip setuptools tox
@@ -67,9 +68,9 @@ jobs:
         needs: [pyright, test]
         if: github.repository == 'python-trio/flake8-async' && github.ref == 'refs/heads/main'
         steps:
-            - uses: actions/checkout@v4
-            - name: Set up Python 3
-              uses: actions/setup-python@v5
+            - uses: actions/checkout@v5
+            - name: Set up Python
+              uses: actions/setup-python@v6
             - name: Install tools
               run: python -m pip install --upgrade build pip setuptools wheel twine gitpython
             - name: Upload new release

.pre-commit-config.yaml

@@ -29,8 +29,9 @@ repos:
       rev: v3.21.0
       hooks:
           - id: pyupgrade
-            args: [--py39-plus]
-            exclude: tests/eval_files/async103.py
+            args: [--py310-plus]
+            # async232 explicitly tests Optional[]
+            exclude: tests/eval_files/async(103|232|232_asyncio).py
 
     - repo: https://github.com/pycqa/isort
       rev: 7.0.0
@@ -41,8 +42,8 @@ repos:
       rev: v1.18.2
       hooks:
           - id: mypy
-            # uses py311 syntax, mypy configured for py39
-            exclude: tests/(eval|autofix)_files/.*_py(310|311).py
+            # uses py311 syntax, mypy configured for py310
+            exclude: tests/(eval|autofix)_files/.*_py311.py
 
     - repo: https://github.com/RobertCraigie/pyright-python
       rev: v1.1.407

flake8_async/__init__.py

@@ -151,7 +151,9 @@ def from_source(
     ) -> Plugin:
         plugin = Plugin.__new__(cls)
         super(Plugin, plugin).__init__()
-        plugin._tree = ast.parse(source)
+        plugin._tree = ast.parse(
+            source, filename=str(filename) if filename is not None else "<unknown>"
+        )
         plugin.filename = str(filename) if filename else None
         plugin.module = cst_parse_module_native(source)
         return plugin

flake8_async/visitors/flake8asyncvisitor.py

@@ -4,7 +4,7 @@
 
 import ast
 from abc import ABC
-from typing import TYPE_CHECKING, Any, Union
+from typing import TYPE_CHECKING, Any
 
 import libcst as cst
 from libcst.metadata import PositionProvider
@@ -16,7 +16,7 @@
 
     from ..runner import SharedState
 
-    HasLineCol = Union[ast.expr, ast.stmt, ast.arg, ast.excepthandler, Statement]
+    HasLineCol = ast.expr | ast.stmt | ast.arg | ast.excepthandler | Statement
 
 
 class Flake8AsyncVisitor(ast.NodeVisitor, ABC):

flake8_async/visitors/helpers.py

@@ -9,7 +9,7 @@
 from collections.abc import Sized
 from dataclasses import dataclass
 from fnmatch import fnmatch
-from typing import TYPE_CHECKING, Generic, TypeVar, Union
+from typing import TYPE_CHECKING, Generic, TypeVar
 
 import libcst as cst
 import libcst.matchers as m
@@ -35,11 +35,9 @@
 
     T = TypeVar("T", bound=Flake8AsyncVisitor)
     T_CST = TypeVar("T_CST", bound=Flake8AsyncVisitor_cst)
-    T_EITHER = TypeVar(
-        "T_EITHER", bound=Union[Flake8AsyncVisitor, Flake8AsyncVisitor_cst]
-    )
+    T_EITHER = TypeVar("T_EITHER", bound=Flake8AsyncVisitor | Flake8AsyncVisitor_cst)
 
-T_Call = TypeVar("T_Call", bound=Union[cst.Call, ast.Call])
+T_Call = TypeVar("T_Call", bound=cst.Call | ast.Call)
 
 
 def error_class(error_class: type[T]) -> type[T]:

flake8_async/visitors/visitor91x.py

@@ -166,17 +166,12 @@ class LoopState:
         default_factory=set[Statement]
     )
     uncheckpointed_before_break: set[Statement] = field(default_factory=set[Statement])
-    # pyright emits reportUnknownVariableType, requiring the generic to default_factory
-    # to be specified.
-    # But for these we require a union, and `|` doesn't work on py39, and uses of
-    # `Union` gets autofixed by ruff.
-    # So.... let's just ignore the error for now
-    artificial_errors: set[  # pyright: ignore[reportUnknownVariableType]
-        cst.Return | cst.Yield
-    ] = field(default_factory=set)
-    nodes_needing_checkpoints: list[  # pyright: ignore[reportUnknownVariableType]
-        cst.Return | cst.Yield | ArtificialStatement
-    ] = field(default_factory=list)
+    artificial_errors: set[cst.Return | cst.Yield] = field(
+        default_factory=set[cst.Return | cst.Yield]
+    )
+    nodes_needing_checkpoints: list[cst.Return | cst.Yield | ArtificialStatement] = (
+        field(default_factory=list[cst.Return | cst.Yield | ArtificialStatement])
+    )
 
     def copy(self):
         return LoopState(

flake8_async/visitors/visitors.py

@@ -128,8 +128,7 @@ def visit_With(self, node: ast.With | ast.AsyncWith):
                 nursery_type = "task group"
                 start_methods = ("create_task",)
             else:
-                # incorrectly marked as not covered on py39
-                continue  # pragma: no cover  # https://github.com/nedbat/coveragepy/issues/198
+                continue
 
             body_call = node.body[0].value
             if isinstance(body_call, ast.Await):

pyproject.toml

@@ -54,7 +54,7 @@ skip_glob = "tests/*_files/*"
 [tool.mypy]
 check_untyped_defs = true
 disable_error_code = ["no-untyped-def", "misc", "no-untyped-call", "no-any-return"]
-python_version = "3.9"
+python_version = "3.10"
 strict = true
 warn_unreachable = true
 warn_unused_ignores = false
@@ -84,7 +84,7 @@ extend-exclude = [
   "tests/autofix_files/*"
 ]
 line-length = 90
-target-version = "py39"
+target-version = "py310"
 
 [tool.ruff.lint]
 ignore = [

tests/autofix_files/async910.py

@@ -430,23 +430,24 @@ async def try_bare_except_reraises():
         ...
 
 
-async def return_in_finally_bare_except_checkpoint():
-    try:
-        await trio.sleep(0)
-    except:
-        await trio.sleep(0)
-    finally:
-        return
-
-
-async def return_in_finally_bare_except_empty():
-    try:
-        await trio.sleep(0)
-    except:
-        ...
-    finally:
-        await trio.lowlevel.checkpoint()
-        return  # error: 8, 'return', Statement('function definition', lineno-6)
+# return in finally is a SyntaxError on py314. We currently don't have
+# test infra to set a max python version for an eval file.
+# async def return_in_finally_bare_except_checkpoint():
+#     try:
+#         await trio.sleep(0)
+#     except:
+#         await trio.sleep(0)
+#     finally:
+#         return
+#
+#
+# async def return_in_finally_bare_except_empty():
+#     try:
+#         await trio.sleep(0)
+#     except:
+#         ...
+#     finally:
+#         return  # error: 8, 'return', Statement('function definition', lineno-6)
 
 
 # early return

tests/autofix_files/async910.py.diff

@@ -154,13 +154,7 @@
 
 
  # safe
-@@ x,16 x,19 @@
-     except:
-         ...
-     finally:
-+        await trio.lowlevel.checkpoint()
-         return  # error: 8, 'return', Statement('function definition', lineno-6)
-
+@@ x,11 x,13 @@
 
  # early return
  async def foo_return_1():

tests/autofix_files/async91x_autofix.py

@@ -144,3 +144,87 @@ async def no_checkpoint():  # ASYNC910: 0, "exit", Statement("function definitio
         except TypeError:
             ...
     await trio.lowlevel.checkpoint()
+
+
+# structural pattern matching
+async def match_subject() -> None:
+    match await foo():
+        case False:
+            pass
+
+
+async def match_not_all_cases() -> (  # ASYNC910: 0, "exit", Statement("function definition", lineno)
+    None
+):
+    match foo():
+        case 1:
+            ...
+        case _:
+            await foo()
+    await trio.lowlevel.checkpoint()
+
+
+async def match_no_fallback() -> (  # ASYNC910: 0, "exit", Statement("function definition", lineno)
+    None
+):
+    match bar():
+        case 1:
+            await foo()
+        case 2:
+            await foo()
+        case _ if True:
+            await foo()
+    await trio.lowlevel.checkpoint()
+
+
+async def match_fallback_is_guarded() -> (  # ASYNC910: 0, "exit", Statement("function definition", lineno)
+    None
+):
+    match bar():
+        case 1:
+            await foo()
+        case 2:
+            await foo()
+        case _ if foo():
+            await foo()
+    await trio.lowlevel.checkpoint()
+
+
+async def match_all_cases() -> None:
+    match bar():
+        case 1:
+            await foo()
+        case 2:
+            await foo()
+        case _:
+            await foo()
+
+
+async def match_fallback_await_in_guard() -> None:
+    # The case guard is only executed if the pattern matches, so we can mostly treat
+    # it as part of the body, except for a special case for fallback+checkpointing guard.
+    match foo():
+        case 1 if await foo():
+            ...
+        case _ if await foo():
+            ...
+
+
+async def match_checkpoint_guard() -> None:
+    # The above pattern is quite cursed, but this seems fairly reasonable to do.
+    match foo():
+        case 1 if await foo():
+            ...
+        case _:
+            await foo()
+
+
+async def match_not_checkpoint_in_all_guards() -> (  # ASYNC910: 0, "exit", Statement("function definition", lineno)
+    None
+):
+    match foo():
+        case 1:
+            ...
+        case _ if await foo():
+            ...
+    await trio.lowlevel.checkpoint()

tests/autofix_files/async91x_autofix.py.diff

@@ -78,8 +78,40 @@
          yield  # ASYNC911: 8, "yield", Statement("function definition", lineno-2) # ASYNC911: 8, "yield", Statement("yield", lineno)
 
          async def bar():
-@@ x,3 x,4 @@
+@@ x,6 x,7 @@
              await foo("1")  # type: ignore[call-arg]
          except TypeError:
              ...
 +    await trio.lowlevel.checkpoint()
+
+
+ # structural pattern matching
+@@ x,6 x,7 @@
+             ...
+         case _:
+             await foo()
++    await trio.lowlevel.checkpoint()
+
+
+ async def match_no_fallback() -> (  # ASYNC910: 0, "exit", Statement("function definition", lineno)
+@@ x,6 x,7 @@
+             await foo()
+         case _ if True:
+             await foo()
++    await trio.lowlevel.checkpoint()
+
+
+ async def match_fallback_is_guarded() -> (  # ASYNC910: 0, "exit", Statement("function definition", lineno)
+@@ x,6 x,7 @@
+             await foo()
+         case _ if foo():
+             await foo()
++    await trio.lowlevel.checkpoint()
+
+
+ async def match_all_cases() -> None:
+@@ x,3 x,4 @@
+             ...
+         case _ if await foo():
+             ...
++    await trio.lowlevel.checkpoint()