Ensure show_contents_list? returns a boolean

The original implementation could result in the method returning nil
rather than true or false. Which is unexpected, and has been a barrier
to changing when and where we display contents lists because of confusing
test failures.

app/presenters/content_item/contents_list.rb

@@ -23,14 +23,23 @@ def show_contents_list?
       return true if contents_items.count > 2
       return false if no_first_item?
 
-      first_item_has_long_content? ||
-        first_item_has_long_table? ||
-        first_item_has_image_and_long_content? ||
-        first_item_has_image_and_long_table?
+      first_item_size_requirements_met?(character_count, table_row_count)
     end
 
   private
 
+    def first_item_size_requirements_met?(char_count, table_row_count)
+      first_item_character_count > char_count || first_item_table_rows > table_row_count
+    end
+
+    def character_count
+      first_item_has_image? ? MINIMUM_CHARACTER_COUNT_IF_IMAGE_PRESENT : MINIMUM_CHARACTER_COUNT
+    end
+
+    def table_row_count
+      first_item_has_image? ? MINIMUM_TABLE_ROW_COUNT_IF_IMAGE_PRESENT : MINIMUM_TABLE_ROW_COUNT
+    end
+
     def extract_headings_with_ids
       headings = parsed_body.css("h2").map do |heading|
         id = heading.attribute("id")
@@ -39,10 +48,6 @@ def extract_headings_with_ids
       headings.compact
     end
 
-    def first_item_has_long_content?
-      first_item_character_count > MINIMUM_CHARACTER_COUNT
-    end
-
     def first_item_content
       element = first_item
       first_item_text = ""
@@ -60,10 +65,6 @@ def first_item_character_count
       @first_item_character_count ||= first_item_content.length
     end
 
-    def first_item_has_long_table?
-      first_item_table_rows > MINIMUM_TABLE_ROW_COUNT
-    end
-
     def find_first_table
       element = first_item
 
@@ -91,14 +92,6 @@ def first_item_has_image?
       end
     end
 
-    def first_item_has_image_and_long_content?
-      first_item_has_image? && first_item_character_count > MINIMUM_CHARACTER_COUNT_IF_IMAGE_PRESENT
-    end
-
-    def first_item_has_image_and_long_table?
-      first_item_has_image? && first_item_table_rows > MINIMUM_TABLE_ROW_COUNT_IF_IMAGE_PRESENT
-    end
-
     def parsed_body
       @parsed_body ||= Nokogiri::HTML(body)
     end