tests: add simple test of formdata password field

tests/test_formdata.py

@@ -144,3 +144,14 @@ def test_get_last_update_time():
     # check with missing 'evolution' values
     formdata.evolution = None
     assert formdata.last_update_time == formdata.receipt_time
+
+def test_password_field():
+    formdef.data_class().wipe()
+    formdef.fields = [fields.PasswordField(id='0', label='pwd')]
+    formdef.store()
+    formdata = formdef.data_class()()
+    formdata.data = {'0': {'cleartext': 'foo'}}
+    formdata.store()
+
+    formdata2 = formdata.get(formdata.id)
+    assert formdata2.data == {'0': {'cleartext': 'foo'}}