Fixes an error where optional fields had to be filled out

Closes #3

HISTORY.rst

@@ -4,6 +4,9 @@ Changelog
 Unreleased
 ~~~~~~~~~~
 
+- Fixes an error where optional fields had to be filled out.
+  [href]
+
 - Adds rudimentary syntax checking with information about which line wrong.
   [href]
 

onegov/form/parser/core.py

@@ -280,7 +280,7 @@
     TextAreaField
 )
 from wtforms.fields.html5 import DateField, DateTimeLocalField, EmailField
-from wtforms.validators import DataRequired, Length
+from wtforms.validators import DataRequired, Length, Optional
 from wtforms.widgets import TextArea
 from wtforms_components import Email, If, TimeField
 
@@ -733,6 +733,8 @@ def add_field(self, field_class, label, required,
                 validator.field_flags = ('required', )
 
                 validators.insert(0, validator)
+        else:
+            validators.insert(0, Optional())
 
         # try to find a smart field_id that contains the dependency or the
         # current fieldset name - if all fails, an error will be thrown,

onegov/form/tests/test_parser.py

@@ -6,6 +6,7 @@
 from textwrap import dedent
 from webob.multidict import MultiDict
 from wtforms import FileField
+from wtforms import validators
 from wtforms.fields.html5 import (
     DateField,
     DateTimeLocalField,
@@ -30,12 +31,16 @@ def test_parse_text():
 
     assert form.first_name.label.text == 'First name'
     assert len(form.first_name.validators) == 1
+    assert isinstance(form.first_name.validators[0], validators.DataRequired)
 
     assert form.last_name.label.text == 'Last name'
-    assert len(form.last_name.validators) == 0
+    assert len(form.last_name.validators) == 1
+    assert isinstance(form.country.validators[0], validators.Optional)
 
     assert form.country.label.text == 'Country'
-    assert len(form.country.validators) == 1
+    assert len(form.country.validators) == 2
+    assert isinstance(form.country.validators[0], validators.Optional)
+    assert isinstance(form.country.validators[1], validators.Length)
 
     assert form.comment.label.text == 'Comment'
     assert form.comment.widget(form.comment) == (
@@ -345,6 +350,27 @@ def test_stdnum_field():
     assert form.errors
 
 
+def test_optional_date():
+
+    text = "Date = YYYY.MM.DD"
+
+    form_class = parse_form(text)
+
+    form = form_class(MultiDict([
+        ('date', '30.02.2015')
+    ]))
+
+    form.validate()
+    assert form.errors == {'date': ['Not a valid date value']}
+
+    form = form_class(MultiDict([
+        ('date', '')
+    ]))
+
+    form.validate()
+    assert not form.errors
+
+
 def test_invalid_syntax():
     with pytest.raises(errors.InvalidFormSyntax) as e:
         parse_form(".")