fixed up class testcase support for py3.6 due to ast differences in p…

…y3.8/3.9

py2cr/types.py

@@ -126,9 +126,15 @@ def visit_Constant(self, node):
 
     @classmethod
     def constant(cls, node, nilable=True):
-        #if not hasattr(node, "value"):
-        #    return "_"
-        const_typename = node.value.__class__.__name__
+        if isinstance(node, ast.Constant): # py3.8+
+            const_typename = node.value.__class__.__name__
+        elif isinstance(node, ast.Num):
+            const_typename = node.n.__class__.__name__
+        elif isinstance(node, ast.Str):
+            const_typename = 'str'
+        else:
+            raise Exception("Invalid constant node: %s", node)
+
         if const_typename in cls.name_map:
             crystal_typename = cls.name_map[const_typename]
             if nilable:

tests/basic/class3.py

@@ -1,7 +1,32 @@
-class A(object):
+class II(object):
     v = 1
 
-a = A()
-XX = A
-x = XX()
-print(x.v)
+class SS(object):
+    v = "abcd"
+
+class FF(object):
+    v = 1.234
+
+ii = II()
+XX = II
+xx = XX()
+print(ii.v)
+print(xx.v)
+print(XX.v)
+
+
+ss = SS()
+YY = SS
+yy = YY()
+print(ss.v)
+print(yy.v)
+print(YY.v)
+
+
+ff = FF()
+ZZ = FF
+zz = ZZ()
+print(ff.v)
+print(zz.v)
+print(ZZ.v)
+