Fix single line formatting of call to action component

We use the default mechanism for parsing so that the parser can handle
abbreviations and footnotes inside call to action component.

Since this change (#292)  we have had a regression where defining a call to
action on a single line does not work as expected (e.g., `$CTA Click here to
start the program $CTA`). The closing `div` is evaluated as markdown and the
call to action component therefore runs on until the next closing `div`.

This can be fixed by adding in some new lines between the div tags.

CHANGELOG.md

@@ -1,3 +1,7 @@
+## Unreleased
+
+* Fix single line formatting of call to action component
+
 ## 8.3.2
 
 * Various bug fixes related to legislative list components ([#298](https://github.com/alphagov/govspeak/pull/298))

lib/govspeak.rb

@@ -277,7 +277,9 @@ def render_image(image)
 
     extension("call-to-action", surrounded_by("$CTA")) do |body|
       <<~BODY
-        <div class="call-to-action" markdown="1">#{body}</div>
+        <div class="call-to-action" markdown="1">
+        #{body.strip}
+        </div>
       BODY
     end
 

test/govspeak_test.rb

@@ -425,6 +425,18 @@ class GovspeakTest < Minitest::Test
     assert_text_output "Click here to start the tool"
   end
 
+  test_given_govspeak "
+    $CTA Click here to start the program $CTA
+
+    Here is some text" do
+    assert_html_output %(
+      <div class="call-to-action">
+        <p>Click here to start the program</p>
+      </div>
+
+      <p>Here is some text</p>)
+  end
+
   test_given_govspeak "
     Here is some text\n
 
@@ -453,7 +465,6 @@ class GovspeakTest < Minitest::Test
     $CTA" do
     assert_html_output %(
         <div class="call-to-action">
-
           <p>This is a test:</p>
 
           <ol class="steps">