Remove value enumeration when validating empty list

tox.ini

@@ -18,7 +18,7 @@ commands =
         --with-coverage3 \
             --cover3-package=voluptuous \
             --cover3-branch \
-        --verbose
+        --verbose {posargs}
 
 [testenv:flake8]
 deps = flake8

voluptuous/schema_builder.py

@@ -615,11 +615,11 @@ def validate_sequence(path, data):
             if not isinstance(data, seq_type):
                 raise er.SequenceTypeInvalid('expected a %s' % seq_type_name, path)
 
-            # Empty seq schema, allow any data.
+            # Empty seq schema, reject any data.
             if not schema:
                 if data:
                     raise er.MultipleInvalid([
-                        er.ValueInvalid('not a valid value', [value]) for value in data
+                        er.ValueInvalid('not a valid value', path if path else data)
                     ])
                 return data
 

voluptuous/tests/tests.py

@@ -1528,3 +1528,17 @@ def test_any_with_discriminant():
         assert_equal(str(e), 'expected bool for dictionary value @ data[\'implementation\'][\'c-value\']')
     else:
         assert False, "Did not raise correct Invalid"
+
+
+def test_empty_list_raises_error_of_key_not_values():
+    """ https://github.com/alecthomas/voluptuous/issues/397 """
+    schema = Schema({
+        Required('variables', default=[]): []
+    })
+
+    try:
+        schema({'variables': ['x']})
+    except MultipleInvalid as e:
+        assert_equal(str(e), "not a valid value for dictionary value @ data['variables']")
+    else:
+        assert False, "Did not raise correct Invalid"