fix: make WuttaQuantity serialize w/ app handler, remove custom widget

turns out we need to always serialize the value via render_quantity()
and the widget becomes redundant

tests/forms/test_schema.py

@@ -1,6 +1,7 @@
 # -*- coding: utf-8; -*-
 
 import datetime
+import decimal
 from unittest import TestCase
 from unittest.mock import patch
 
@@ -15,7 +16,7 @@ from wuttaweb.forms import widgets
 from wuttaweb.testing import DataTestCase, WebTestCase
 
 
-class TestWutaDateTime(TestCase):
+class TestWuttaDateTime(TestCase):
 
     def test_deserialize(self):
         typ = mod.WuttaDateTime()
@@ -91,11 +92,25 @@ class TestWuttaMoney(WebTestCase):
 
 class TestWuttaQuantity(WebTestCase):
 
-    def test_widget_maker(self):
-        enum = self.app.enum
-        typ = mod.WuttaQuantity(self.request)
-        widget = typ.widget_maker()
-        self.assertIsInstance(widget, widgets.WuttaQuantityWidget)
+    def test_serialize(self):
+        node = colander.SchemaNode(mod.WuttaQuantity(self.request))
+        typ = node.typ
+
+        # null
+        result = typ.serialize(node, colander.null)
+        self.assertIs(result, colander.null)
+        result = typ.serialize(node, None)
+        self.assertIs(result, colander.null)
+
+        # quantity
+        result = typ.serialize(node, 42)
+        self.assertEqual(result, '42')
+        result = typ.serialize(node, 42.00)
+        self.assertEqual(result, '42')
+        result = typ.serialize(node, decimal.Decimal('42.00'))
+        self.assertEqual(result, '42')
+        result = typ.serialize(node, 42.13)
+        self.assertEqual(result, '42.13')
 
 
 class TestObjectRef(DataTestCase):