make delegating generators say they running (closes #14220)

1 files changed, 72 insertions, 0 deletions

diff --git a/Lib/test/test_pep380.py b/Lib/test/test_pep380.py
index 3a1db29..bdcfacd 100644
--- a/Lib/test/test_pep380.py
+++ b/Lib/test/test_pep380.py
@@ -847,6 +847,78 @@ class TestPEP380Operation(unittest.TestCase):
             yield from ()
         self.assertRaises(StopIteration, next, g())
 
+    def test_delegating_generators_claim_to_be_running(self):
+        # Check with basic iteration
+        def one():
+            yield 0
+            yield from two()
+            yield 3
+        def two():
+            yield 1
+            try:
+                yield from g1
+            except ValueError:
+                pass
+            yield 2
+        g1 = one()
+        self.assertEqual(list(g1), [0, 1, 2, 3])
+        # Check with send
+        g1 = one()
+        res = [next(g1)]
+        try:
+            while True:
+                res.append(g1.send(42))
+        except StopIteration:
+            pass
+        self.assertEqual(res, [0, 1, 2, 3])
+        # Check with throw
+        class MyErr(Exception):
+            pass
+        def one():
+            try:
+                yield 0
+            except MyErr:
+                pass
+            yield from two()
+            try:
+                yield 3
+            except MyErr:
+                pass
+        def two():
+            try:
+                yield 1
+            except MyErr:
+                pass
+            try:
+                yield from g1
+            except ValueError:
+                pass
+            try:
+                yield 2
+            except MyErr:
+                pass
+        g1 = one()
+        res = [next(g1)]
+        try:
+            while True:
+                res.append(g1.throw(MyErr))
+        except StopIteration:
+            pass
+        # Check with close
+        class MyIt(object):
+            def __iter__(self):
+                return self
+            def __next__(self):
+                return 42
+            def close(self_):
+                self.assertTrue(g1.gi_running)
+                self.assertRaises(ValueError, next, g1)
+        def one():
+            yield from MyIt()
+        g1 = one()
+        next(g1)
+        g1.close()
+
 
 def test_main():
     from test import support