Handle incorrect content IDs found in embeds

Previously, an uncaught error was raised if a
content block's content ID couldn't be found,
which prevented any editions being published if
they had an incorrect embed code within them.
There was no feedback for the user on Mainstream
when this happened and it looks like the edition
*has* been published, on Whitehall a nondescript
server error is shown to users when attempting to
publish.

When a Host Edition is updated at the content PUT
endpoint and embedded content links are looked
for, this change sends an exception to Sentry to
alert developers the issue has occurred, and does
not add the incorrect ID to the Links on an
Edition.

When the content is then rendered by the
`ContentEmbedPresenter`, we again check whether
the corresponding Edition exists and alert Sentry
again.

The user should be able to see their changes
published, and the embed code will appear as plain
text on the frontend, so it should be easy to spot
and change.

app/presenters/content_embed_presenter.rb

@@ -59,10 +59,17 @@ def render_embedded_editions(content)
       embedded_content_references.uniq.each do |content_reference|
         embed_code = content_reference.embed_code
         embedded_edition = embedded_editions[content_reference.content_id]
-        content = content.gsub(
-          embed_code,
-          get_content_for_edition(embedded_edition, embed_code),
-        )
+        if embedded_edition.present?
+          content = content.gsub(
+            embed_code,
+            get_content_for_edition(embedded_edition, embed_code),
+          )
+        else
+          Sentry.capture_exception(CommandError.new(
+                                     code: 422,
+                                     message: "Could not find a live edition for embedded content ID: #{content_reference.content_id}",
+                                   ))
+        end
       end
 
       content

app/services/embedded_content_finder_service.rb

@@ -4,8 +4,7 @@ def fetch_linked_content_ids(details, locale)
       find_content_references(value)
     }.flatten.compact
 
-    check_all_references_exist(content_references.uniq, locale)
-    content_references.map(&:content_id)
+    live_content_ids(content_references, locale)
   end
 
   def find_content_references(value)
@@ -23,16 +22,17 @@ def find_content_references(value)
 
 private
 
-  def check_all_references_exist(content_references, locale)
-    found_editions = live_editions(content_references, locale)
+  def live_content_ids(content_references, locale)
+    found_editions = live_editions(content_references.uniq, locale)
     not_found_content_ids = content_references.map(&:content_id) - found_editions.map(&:content_id)
 
     if not_found_content_ids.any?
-      raise CommandError.new(
-        code: 422,
-        message: "Could not find any live editions in locale #{locale} for: #{not_found_content_ids.join(', ')}, ",
-      )
+      Sentry.capture_exception(CommandError.new(
+                                 code: 422,
+                                 message: "Could not find any live editions for embedded content IDs: #{not_found_content_ids.join(', ')}",
+                               ))
     end
+    content_references.map(&:content_id) - not_found_content_ids
   end
 
   def live_editions(content_references, locale)

spec/integration/put_content/content_with_embedded_content_spec.rb

@@ -312,11 +312,11 @@
       payload.merge!(document_type: "press_release", schema_name: "news_article", details: { body: "{{embed:contact:#{fake_content_id}}}" })
     end
 
-    it "should return a 422 error" do
+    it "should not create a new Link" do
       put "/v2/content/#{content_id}", params: payload.to_json
 
-      expect(response).to be_unprocessable
-      expect(response.body).to match(/Could not find any live editions in locale en for: #{fake_content_id}/)
+      expect(response).to be_ok
+      expect(Link.find_by(target_content_id: fake_content_id)).to be_nil
     end
   end
 
@@ -330,11 +330,13 @@
       payload.merge!(document_type: "press_release", schema_name: "news_article", details: { body: "{{embed:contact:#{contact.document.content_id}}} {{embed:contact:#{first_fake_content_id}}} {{embed:contact:#{second_fake_content_id}}}" })
     end
 
-    it "should return a 422 error" do
+    it "should return a 200 with only the existing links" do
       put "/v2/content/#{content_id}", params: payload.to_json
 
-      expect(response).to be_unprocessable
-      expect(response.body).to match(/Could not find any live editions in locale en for: #{first_fake_content_id}, #{second_fake_content_id}/)
+      expect(response).to be_ok
+      expect(Link.find_by(target_content_id: first_fake_content_id)).to be_nil
+      expect(Link.find_by(target_content_id: second_fake_content_id)).to be_nil
+      expect(Link.find_by(target_content_id: contact.document.content_id)).not_to be_nil
     end
   end