Add stricter checking to "from ... import ..."

CHANGES

@@ -28,10 +28,12 @@ Version 2.10
 - Add ``min`` and ``max`` filters. (`#475`_)
 - Add tests for all comparison operators: ``eq``, ``ne``, ``lt``, ``le``,
   ``gt``, ``ge``. (`#665`_)
+- ``import`` statement cannot end with a trailing comma. (`#618`_)
 
 .. _#469: https://github.com/pallets/jinja/pull/469
 .. _#475: https://github.com/pallets/jinja/pull/475
 .. _#478: https://github.com/pallets/jinja/pull/478
+.. _#618: https://github.com/pallets/jinja/pull/618
 .. _#665: https://github.com/pallets/jinja/pull/665
 
 Version 2.9.6

jinja2/parser.py

@@ -334,7 +334,7 @@ def parse_context():
                 if parse_context() or self.stream.current.type != 'comma':
                     break
             else:
-                break
+                self.stream.expect('name')
         if not hasattr(node, 'with_context'):
             node.with_context = False
             self.stream.skip_if('comma')

tests/test_imports.py

@@ -11,7 +11,8 @@
 import pytest
 
 from jinja2 import Environment, DictLoader
-from jinja2.exceptions import TemplateNotFound, TemplatesNotFound
+from jinja2.exceptions import TemplateNotFound, TemplatesNotFound, \
+    TemplateSyntaxError
 
 
 @pytest.fixture
@@ -50,7 +51,24 @@ def test_context_imports(self, test_env):
         )
         assert t.render(foo=42) == '[42|23]'
 
-    def test_trailing_comma(self, test_env):
+    def test_import_needs_name(self, test_env):
+        test_env.from_string('{% from "foo" import bar %}')
+        test_env.from_string('{% from "foo" import bar, baz %}')
+
+        with pytest.raises(TemplateSyntaxError):
+            test_env.from_string('{% from "foo" import %}')
+
+    def test_no_trailing_comma(self, test_env):
+        with pytest.raises(TemplateSyntaxError):
+            test_env.from_string('{% from "foo" import bar, %}')
+
+        with pytest.raises(TemplateSyntaxError):
+            test_env.from_string('{% from "foo" import bar,, %}')
+
+        with pytest.raises(TemplateSyntaxError):
+            test_env.from_string('{% from "foo" import, %}')
+
+    def test_trailing_comma_with_context(self, test_env):
         test_env.from_string('{% from "foo" import bar, baz with context %}')
         test_env.from_string('{% from "foo" import bar, baz, with context %}')
         test_env.from_string('{% from "foo" import bar, with context %}')