test: itertools.chain stop iteration on error

Author: rng-dynamics

extra_tests/snippets/stdlib_itertools.py

@@ -57,6 +57,12 @@
 assert next(x) == 0
 assert next(x) == 1
 
+x = chain(1, [2])
+with assert_raises(TypeError):
+    next(x)
+with assert_raises(StopIteration):
+    next(x)
+
 # itertools.count tests
 
 # default arguments