add match support to 103/104

Author: jakkdl

.pre-commit-config.yaml

@@ -42,7 +42,7 @@ repos:
       hooks:
           - id: mypy
             # uses py311 syntax, mypy configured for py39
-            exclude: tests/(eval|autofix)_files/.*_py311.py
+            exclude: tests/(eval|autofix)_files/.*_py(310|311).py
 
     - repo: https://github.com/RobertCraigie/pyright-python
       rev: v1.1.396

flake8_async/visitors/visitor103_104.py

@@ -199,6 +199,25 @@ def visit_If(self, node: ast.If):
         # if body didn't raise, or it's unraised after else, set unraise
         self.unraised = not body_raised or self.unraised
 
+    def visit_Match(self, node: ast.Match):  # type: ignore[name-defined]
+        if not self.unraised:
+            return
+        self.visit(node.subject)  # this doesn't matter for 103/104, idr if it matters
+        all_cases_raise = True
+        has_fallback = False
+        for case in node.cases:
+            # check for "bare pattern", i.e `case varname:`
+            has_fallback |= (
+                case.guard is None
+                and isinstance(case.pattern, ast.MatchAs)  # type: ignore[attr-defined]
+                and case.pattern.pattern is None
+            )
+            self.visit_nodes(case.body)
+            all_cases_raise &= not self.unraised
+            self.unraised = True
+
+        self.unraised = not (all_cases_raise and has_fallback)
+
     # A loop is guaranteed to raise if:
     # condition always raises, or
     #   else always raises, and

tests/eval_files/async103_104_py310.py

@@ -0,0 +1,58 @@
+"""Test for ASYNC103/ASYNC104 with structural pattern matching
+
+ASYNC103: no-reraise-cancelled
+ASYNC104: cancelled-not-raised
+"""
+
+# ARG --enable=ASYNC103,ASYNC104
+
+
+def foo() -> Any: ...
+
+
+try:
+    ...
+except BaseException as e:  # ASYNC103_trio: 7, "BaseException"
+    match foo():
+        case True:
+            raise e
+        case False:
+            ...
+        case _:
+            raise e
+
+try:
+    ...
+except BaseException:  # ASYNC103_trio: 7, "BaseException"
+    match foo():
+        case True:
+            raise
+
+try:
+    ...
+except BaseException:  # safe
+    match foo():
+        case True:
+            raise
+        case False:
+            raise
+        case _:
+            raise
+try:
+    ...
+except BaseException:  # ASYNC103_trio: 7, "BaseException"
+    match foo():
+        case _ if foo():
+            raise
+try:
+    ...
+except BaseException:  # ASYNC103_trio: 7, "BaseException"
+    match foo():
+        case 1:
+            return  # ASYNC104: 12
+        case 2:
+            raise
+        case 3:
+            return  # ASYNC104: 12
+        case blah:
+            raise