Add 'yield' inside async function' for Python 3.5.

parso/python/normalizer.py

@@ -603,10 +603,14 @@ class ErrorFinder(Normalizer):
         elif leaf.value in ('yield', 'return'):
             if self._context.node.type != 'funcdef':
                 self._add_syntax_error("'%s' outside function" % leaf.value, leaf.parent)
-            elif self._context.is_async_funcdef() and leaf.value == 'return' \
-                    and leaf.parent.type == 'return_stmt' \
+            elif self._context.is_async_funcdef() \
                     and any(self._context.node.iter_yield_exprs()):
+                if leaf.value == 'return' and leaf.parent.type == 'return_stmt':
                     self._add_syntax_error("'return' with value in async generator", leaf.parent)
+                elif leaf.value == 'yield' \
+                        and leaf.get_next_leaf() != 'from' \
+                        and self._version == (3, 5):
+                    self._add_syntax_error("'yield' inside async function", leaf.parent)
         elif leaf.value == 'await':
             if not self._context.is_async_funcdef():
                 self._add_syntax_error("'await' outside async function", leaf.parent)

test/normalizer_issue_files/allowed_syntax_python3.5.py

@@ -4,7 +4,6 @@ Mostly allowed syntax in Python 3.5.
 
 
 async def foo():
-    yield 1
     await bar()
     #: E901
     yield from []
@@ -16,7 +15,6 @@ async def foo():
 # With decorator it's a different statement.
 @bla
 async def foo():
-    yield 1
     await bar()
     #: E901
     yield from []

test/test_python_errors.py

@@ -119,6 +119,7 @@ FAILING_EXAMPLES = [
     r'b"\x"',
     r'b"\"',
     '*a, *b = 3, 3',
+    'async def foo(): yield from []',
 
     # Parser/tokenize.c
     r'"""',
@@ -264,6 +265,17 @@ if sys.version_info >= (2, 7):
     # versions. Just skip it for 2.6.
     FAILING_EXAMPLES.append('[a, 1] += 3')
 
+if sys.version_info[:2] == (3, 5):
+    FAILING_EXAMPLES += [
+        'async def foo():\n yield x',
+        'async def foo():\n yield x',
+    ]
+else:
+    FAILING_EXAMPLES += [
+        'async def foo():\n yield x\n return 1',
+        'async def foo():\n yield x\n return 1',
+    ]
+
 
 def _get_error_list(code, version=None):
     grammar = parso.load_grammar(version=version)
@@ -378,9 +390,6 @@ def test_default_except_error_postition():
         # SyntaxError
         ('async def bla():\n def x():  await bla()', '3.5'),
         ('yield from []', '3.5'),
-        ('async def foo(): yield from []', '3.5'),
-        ('async def foo():\n yield x\n return 1', '3.6'),
-        ('async def foo():\n yield x\n return 1', '3.6'),
         ('*a = 3', '3.5'),
         ('del *a, b', '3.5'),
         ('def x(*): pass', '3.5'),