bpo-46542: test_json uses support.infinite_recursion() (GH-30972)

Fix test_json tests checking for RecursionError: modify these tests
to use support.infinite_recursion().
(cherry picked from commit e7a6285f1be18992191599792524d3aa6aedfa55)

Co-authored-by: Victor Stinner <vstinner@python.org>

2 files changed, 15 insertions, 6 deletions

diff --git a/Lib/test/test_json/test_recursion.py b/Lib/test/test_json/test_recursion.py
index 543c628..9919d7f 100644
--- a/Lib/test/test_json/test_recursion.py
+++ b/Lib/test/test_json/test_recursion.py
@@ -1,3 +1,4 @@
+from test import support
 from test.test_json import PyTest, CTest
 
 
@@ -69,11 +70,14 @@ class TestRecursion:
         # test that loading highly-nested objects doesn't segfault when C
         # accelerations are used. See #12017
         with self.assertRaises(RecursionError):
-            self.loads('{"a":' * 100000 + '1' + '}' * 100000)
+            with support.infinite_recursion():
+                self.loads('{"a":' * 100000 + '1' + '}' * 100000)
         with self.assertRaises(RecursionError):
-            self.loads('{"a":' * 100000 + '[1]' + '}' * 100000)
+            with support.infinite_recursion():
+                self.loads('{"a":' * 100000 + '[1]' + '}' * 100000)
         with self.assertRaises(RecursionError):
-            self.loads('[' * 100000 + '1' + ']' * 100000)
+            with support.infinite_recursion():
+                self.loads('[' * 100000 + '1' + ']' * 100000)
 
     def test_highly_nested_objects_encoding(self):
         # See #12051
@@ -81,9 +85,11 @@ class TestRecursion:
         for x in range(100000):
             l, d = [l], {'k':d}
         with self.assertRaises(RecursionError):
-            self.dumps(l)
+            with support.infinite_recursion():
+                self.dumps(l)
         with self.assertRaises(RecursionError):
-            self.dumps(d)
+            with support.infinite_recursion():
+                self.dumps(d)
 
     def test_endless_recursion(self):
         # See #12051
@@ -93,7 +99,8 @@ class TestRecursion:
                 return [o]
 
         with self.assertRaises(RecursionError):
-            EndlessJSONEncoder(check_circular=False).encode(5j)
+            with support.infinite_recursion():
+                EndlessJSONEncoder(check_circular=False).encode(5j)
 
 
 class TestPyRecursion(TestRecursion, PyTest): pass
diff --git a/Misc/NEWS.d/next/Tests/2022-01-28-01-17-10.bpo-46542.xRLTdj.rst b/Misc/NEWS.d/next/Tests/2022-01-28-01-17-10.bpo-46542.xRLTdj.rst
new file mode 100644
index 0000000..c6b64ce
--- /dev/null
+++ b/Misc/NEWS.d/next/Tests/2022-01-28-01-17-10.bpo-46542.xRLTdj.rst
@@ -0,0 +1,2 @@
+Fix ``test_json`` tests checking for :exc:`RecursionError`: modify these tests
+to use ``support.infinite_recursion()``. Patch by Victor Stinner.