style: add _LatentStyle.delete()

Author: Steve Canny

docx/oxml/styles.py

@@ -85,6 +85,12 @@ class CT_LsdException(BaseOxmlElement):
     uiPriority = OptionalAttribute('w:uiPriority', ST_DecimalNumber)
     unhideWhenUsed = OptionalAttribute('w:unhideWhenUsed', ST_OnOff)
 
+    def delete(self):
+        """
+        Remove this `w:lsdException` element from the XML document.
+        """
+        self.getparent().remove(self)
+
     def on_off_prop(self, attr_name):
         """
         Return the boolean value of the attribute having *attr_name*, or

docx/styles/latent.py

@@ -136,6 +136,16 @@ class _LatentStyle(ElementProxy):
 
     __slots__ = ()
 
+    def delete(self):
+        """
+        Remove this latent style definition such that the defaults defined in
+        the containing |LatentStyles| object provide the effective value for
+        each of its attributes. Attempting to access any attributes on this
+        object after calling this method will raise |AttributeError|.
+        """
+        self._element.delete()
+        self._element = None
+
     @property
     def hidden(self):
         """

features/sty-latent-add-del.feature

@@ -11,7 +11,6 @@ Feature: Add or delete a latent style
       And latent_styles['Foobar'] is a latent style
 
 
-  @wip
   Scenario: Delete a latent style
     Given a document having known styles
      When I delete a latent style

tests/styles/test_latent.py

@@ -17,6 +17,12 @@
 
 class DescribeLatentStyle(object):
 
+    def it_can_delete_itself(self, delete_fixture):
+        latent_style, latent_styles, expected_xml = delete_fixture
+        latent_style.delete()
+        assert latent_styles.xml == expected_xml
+        assert latent_style._element is None
+
     def it_knows_its_name(self, name_get_fixture):
         latent_style, expected_value = name_get_fixture
         assert latent_style.name == expected_value
@@ -42,6 +48,13 @@ def it_can_change_its_on_off_properties(self, on_off_set_fixture):
 
     # fixtures -------------------------------------------------------
 
+    @pytest.fixture
+    def delete_fixture(self):
+        latent_styles = element('w:latentStyles/w:lsdException{w:name=Foo}')
+        latent_style = _LatentStyle(latent_styles[0])
+        expected_xml = xml('w:latentStyles')
+        return latent_style, latent_styles, expected_xml
+
     @pytest.fixture(params=[
         ('w:lsdException{w:name=Foobar}', 'Foobar'),
     ])