Explode loudly when a Python type makes it into Sass-land.

2 files changed, 13 insertions, 8 deletions

diff --git a/scss/rule.py b/scss/rule.py
index ea54873..8f84c9b 100644
--- a/scss/rule.py
+++ b/scss/rule.py
@@ -5,6 +5,7 @@ import six
 import logging
 
 from scss.cssdefs import _has_placeholder_re
+from scss.types import Value
 
 
 log = logging.getLogger(__name__)
@@ -88,8 +89,8 @@ class Namespace(object):
 
     def set_variable(self, name, value):
         name = normalize_var(name)
-        assert not (isinstance(value, six.string_types) and value.startswith('$'))
-        #assert isinstance(value, Value)
+        if not isinstance(value, Value):
+            raise TypeError("Expected a Sass type, got %r" % (item,))
         self._variables[name] = value
 
     def _get_callable(self, chainmap, name, arity):
diff --git a/scss/types.py b/scss/types.py
index 40aa595..4a1cf50 100644
--- a/scss/types.py
+++ b/scss/types.py
@@ -453,14 +453,18 @@ class List(Value):
 
     sass_type_name = u'list'
 
-    def __init__(self, tokens, separator=None, use_comma=None):
-        if isinstance(tokens, List):
-            tokens = tokens.value
+    def __init__(self, iterable, separator=None, use_comma=None):
+        if isinstance(iterable, List):
+            iterable = iterable.value
 
-        if not isinstance(tokens, (list, tuple)):
-            raise TypeError("Expected list, got %r" % (tokens,))
+        if not isinstance(iterable, (list, tuple)):
+            raise TypeError("Expected list, got %r" % (iterable,))
 
-        self.value = list(tokens)
+        self.value = list(iterable)
+
+        for item in self.value:
+            if not isinstance(item, Value):
+                raise TypeError("Expected a Sass type, got %r" % (item,))
 
         # TODO remove separator argument entirely
         if use_comma is None: