Write to test updating namespaces

tests/test_attr_update.py

@@ -9,3 +9,29 @@ def test_attr_update_new(test_cache):
     it1 = test_cache.search('testattrupdate')[0]
 
     assert it1.attrs == {**attrs0, **attrs1}
+
+
+def test_update_attr_namespaces(test_cache):
+
+    attrs0 = {
+        'foo': 'bar',
+        'attrdict': {
+            'numbers': [0, 1, 2, 3, 4]
+        }
+    }
+
+    it = test_cache.best_or_new('updatenamespace', attrs = attrs0)
+    it1 = test_cache.search('updatenamespace')[0]
+
+    assert it1.attrs == attrs0
+
+    attrs1 = {
+        'foo': 'bar',
+        'attrdict': {
+            'numbers': [5, 6, 7, 8]
+        }
+    }
+    test_cache.update(it.uri, update = {'attrs': attrs1})
+    it2 = test_cache.search('updatenamespace')[0]
+
+    assert it2.attrs == attrs1