Fix visual bug with contents list manually numbered headings

If the headings had trailing spaces, the regex would not fire

CHANGELOG.md

@@ -7,6 +7,10 @@
   useful summary for people upgrading their application, not a replication
   of the commit log.
 
+## Unreleased
+
+* Fix visual bug with contents list manually numbered headings ([PR #3694](https://github.com/alphagov/govuk_publishing_components/pull/3694))
+
 ## 35.21.0
 
 * Add metadata inverse no padding option ([PR #3689](https://github.com/alphagov/govuk_publishing_components/pull/3689))

lib/govuk_publishing_components/presenters/contents_list_helper.rb

@@ -24,13 +24,13 @@ def list_item_classes(list_item, nested)
 
       def wrap_numbers_with_spans(content_item_link)
         content_item_text = strip_tags(content_item_link) # just the text of the link
-
+        content_item_text_stripped = content_item_text.strip # strip trailing spaces for the regex. Keep original content_item_text for the string replacement.
         # Must start with a number
         # Number must be between 1 and 999 (ie not 2014)
         # Must be followed by a space
         # May contain a period `1.`
         # May be a decimal `1.2`
-        number = /^\d{1,3}(\.?|\.\d{1,2})(?=\s)/.match(content_item_text)
+        number = /^\d{1,3}(\.?|\.\d{1,2})(?=\s)/.match(content_item_text_stripped)
 
         if number
           words = content_item_text.sub(number.to_s, "").strip # remove the number from the text

spec/lib/govuk_publishing_components/components/contents_list_helper_spec.rb

@@ -11,6 +11,12 @@
       assert_split_number_and_text("100. Thing", "100.", "Thing")
     end
 
+    it "accounts for trailing spaces in the heading" do
+      assert_split_number_and_text(" 1. Thing", "1.", "Thing")
+      assert_split_number_and_text(" 10. Thing ", "10.", "Thing")
+      assert_split_number_and_text("100. Thing ", "100.", "Thing")
+    end
+
     it "keeps a space between number and text for screen reader pronunciation" do
       cl = GovukPublishingComponents::Presenters::ContentsListHelper.new({})
       # 1.Thing can be pronounced "1 dot Thing"