add tests about parenthesized context managers

Author: isidentical

tests/data/parenthesized_context_managers.py

@@ -0,0 +1,21 @@
+with (CtxManager() as example):
+    ...
+
+with (CtxManager1(), CtxManager2()):
+    ...
+
+with (CtxManager1() as example, CtxManager2()):
+    ...
+
+with (CtxManager1(), CtxManager2() as example):
+    ...
+
+with (CtxManager1() as example1, CtxManager2() as example2):
+    ...
+
+with (
+    CtxManager1() as example1,
+    CtxManager2() as example2,
+    CtxManager3() as example3,
+):
+    ...

tests/test_format.py

@@ -70,7 +70,11 @@
     "percent_precedence",
 ]
 
-PY310_CASES = ["pattern_matching_simple", "pattern_matching_complex"]
+PY310_CASES = [
+    "pattern_matching_simple",
+    "pattern_matching_complex",
+    "parenthesized_context_managers",
+]
 
 SOURCES = [
     "src/black/__init__.py",