Fix `as_string` for one element tuples.

2 files changed, 11 insertions, 0 deletions

diff --git a/as_string.py b/as_string.py
index b7e62571..72c5b6c3 100644
--- a/as_string.py
+++ b/as_string.py
@@ -399,6 +399,8 @@ class AsStringVisitor(object):
 
     def visit_tuple(self, node):
         """return an astroid.Tuple node as string"""
+        if len(node.elts) == 1:
+            return '(%s, )' % node.elts[0].accept(self) 
         return '(%s)' % ', '.join([child.accept(self) for child in node.elts])
 
     def visit_unaryop(self, node):
diff --git a/test/unittest_nodes.py b/test/unittest_nodes.py
index 14813bb8..514487c0 100644
--- a/test/unittest_nodes.py
+++ b/test/unittest_nodes.py
@@ -35,6 +35,15 @@ abuilder = builder.AstroidBuilder()
 
 class AsString(testlib.TestCase):
 
+    def test_tuple_as_string(self):
+        def build(string):
+            return abuilder.string_build(string).body[0].value
+
+        self.assertEqual(build('1,').as_string(), '(1, )')
+        self.assertEqual(build('1, 2, 3').as_string(), '(1, 2, 3)')
+        self.assertEqual(build('(1, )').as_string(), '(1, )')
+        self.assertEqual(build('1, 2, 3').as_string(), '(1, 2, 3)')
+
     def test_varargs_kwargs_as_string(self):
         ast = abuilder.string_build( 'raise_string(*args, **kwargs)').body[0]
         self.assertEqual(ast.as_string(), 'raise_string(*args, **kwargs)')