Make zip raise any exceptions from iterators

aioitertools/builtins.py

@@ -427,11 +427,17 @@ async def zip(*itrs: AnyIterable[Any]) -> AsyncIterator[Tuple[Any, ...]]:
 
     """
     its: List[AsyncIterator[Any]] = [iter(itr) for itr in itrs]
+    ok = True
 
-    while True:
+    while ok:
         values = await asyncio.gather(
             *[it.__anext__() for it in its], return_exceptions=True
         )
-        if builtins.any(isinstance(v, AnyStop) for v in values):
-            break
-        yield builtins.tuple(values)
+        for v in values:
+            if isinstance(v, BaseException):
+                if isinstance(v, AnyStop):
+                    ok = False
+                    break
+                raise v
+        if ok:
+            yield builtins.tuple(values)

aioitertools/tests/builtins.py

@@ -370,3 +370,20 @@ class BuiltinsTest(TestCase):
         result = await ait.list(ait.zip(short, long))
         expected = [("a", 0), ("b", 1), ("c", 2)]
         self.assertListEqual(expected, result)
+
+    @async_test
+    async def test_zip_exception(self):
+        async def raise_after(x: int):
+            for i in range(x):
+                yield i
+            assert False
+
+        short = raise_after(2)
+        long = ["a", "b", "c"]
+
+        gen = ait.zip(short, long)
+        self.assertEqual((0, "a"), await ait.next(gen))
+        self.assertEqual((1, "b"), await ait.next(gen))
+
+        with self.assertRaises(AssertionError):
+            await ait.next(gen)