Merge pull request #25834 from guardian/pf/refactor-contributor-index

admin/app/jobs/RebuildIndexJob.scala

@@ -96,7 +96,17 @@ class RebuildIndexJob(contentApiClient: ContentApiClient)(implicit executionCont
       contributors <- contentApiTagsEnumerator.enumerateTagType("contributor")
     } yield {
       val contributorsByNameOrder: Map[String, Set[Tag]] = contributors.toSet
-        .groupBy(tag => tagPages.alphaIndexKey(tag.lastName orElse tag.firstName getOrElse tag.webTitle))
+        .groupBy(tag => {
+
+          /**
+            * The alphaIndexKey function looks at the first alphanumeric character in the string passed to it.
+            * Concatenating these three strings therefore allows us to use firstName and webTitle as fallbacks
+            * if lastName is None or "".
+            * */
+          val indexString =
+            tag.lastName.getOrElse("").trim.concat(tag.firstName.getOrElse("").trim).concat(tag.webTitle)
+          tagPages.alphaIndexKey(indexString)
+        })
 
       blocking {
         saveToS3("contributors", tagPages.toPages(contributorsByNameOrder)(alphaTitle, tagPages.nameOrder))