TWE-62: Add PromoBlock to ServiceAreaPage (with link optional)

Author: bmispelon

tbx/project_styleguide/templates/patterns/molecules/streamfield/blocks/promo_block.html

@@ -4,7 +4,9 @@
     <div class="promo-block__content">
         {% include "patterns/atoms/section-title/section-title.html" with title=value.title classes="promo-block__title" %}
         <p class="promo-block__description">{{ value.description }}</p>
-        <a href="{{ value.get_button_link }}" class="button promo-block__button">{{ value.button_text }}</a>
+        {% if value.button_text %}
+            <a href="{{ value.get_button_link }}" class="button promo-block__button">{{ value.button_text }}</a>
+        {% endif %}
         {% if value.secondary_link %}
             <hr class="promo-block__divider" aria-hidden="true" />
             {% with secondary_link=value.secondary_link.0.value %}

tbx/services/blocks.py

@@ -69,9 +69,23 @@ class ServiceStoryBlock(StoryBlock):
     )
 
 
+class OptionalLinkPromoBlock(PromoBlock):
+    """
+    Identical to PromoBlock in all aspects, except that button_link is optional.
+    """
+
+    button_text = blocks.CharBlock(max_length=55, required=False)
+    button_link = blocks.StreamBlock(
+        PromoBlock.declared_blocks["button_link"].child_blocks.items(),
+        required=False,
+        max_num=1,
+    )
+
+
 class ServiceAreaStoryBlock(StoryBlock):
     blog_chooser = BlogChooserBlock()
     four_photo_collage = FourPhotoCollageBlock()
     key_points = IconKeyPointsBlock(label="Key points with icons")
     link_columns = LinkColumnsBlock()
+    promo = OptionalLinkPromoBlock()
     work_chooser = WorkChooserBlock()

tbx/services/tests/__init__.py

@@ -0,0 +1,35 @@
+from django.test import SimpleTestCase
+
+from wagtail.blocks.struct_block import StructBlockValidationError
+
+from tbx.services.blocks import OptionalLinkPromoBlock, PromoBlock
+
+
+class OptionalLinkPromoBlockTestCase(SimpleTestCase):
+    def test_basic_promo_block_button_link_required(self):
+        try:
+            PromoBlock().clean({"button_link": []})
+        except StructBlockValidationError:
+            pass
+        else:
+            self.fail("PromoBlock.button_link should be required")
+
+    def test_custom_promo_block_button_link_optional(self):
+        try:
+            OptionalLinkPromoBlock().clean({"button_link": []})
+        except StructBlockValidationError as e:
+            self.fail(e.as_json_data())
+
+    def test_basic_promo_block_button_text_required(self):
+        try:
+            PromoBlock().clean({"button_text": ""})
+        except StructBlockValidationError:
+            pass
+        else:
+            self.fail("PromoBlock.button_text should be required")
+
+    def test_custom_promo_block_button_text_optional(self):
+        try:
+            OptionalLinkPromoBlock().clean({"button_text": ""})
+        except StructBlockValidationError as e:
+            self.fail(e.as_json_data())