Exclude source from displayed highlights

Why these changes are being introduced:

The 'source' field is now redundant with the
search tab names.

Relevant ticket(s):

- [USE-362](https://mitlibraries.atlassian.net/browse/USE-362)

How this addresses that need:

This adds 'source' to the `displayed_fields`
method in the Search Helper, thus excluding it
from displayed highlights.

Side effects of this change:

None.

Author: jazairi

app/helpers/search_helper.rb

@@ -1,8 +1,9 @@
 module SearchHelper
   # These fields are used to filter out highlights that are already displayed in the main result view. Keep in mind these values need to be the names of fields in TIMDEX, not the normalized record keys.
+  # Source is included because the selected search tab indicates the source.
   def displayed_fields
     ['title', 'title.exact_value', 'content_type', 'dates.value', 'contributors.value', 'summary', 'citation',
-     'subjects.value']
+     'subjects.value', 'source']
   end
 
   def trim_highlights(result)

test/helpers/search_helper_test.rb

@@ -8,7 +8,8 @@ class SearchHelperTest < ActionView::TestCase
                            { 'matchedField' => 'title.exact_value', 'matchedPhrases' => 'Very important data' },
                            { 'matchedField' => 'content_type', 'matchedPhrases' => 'Dataset' },
                            { 'matchedField' => 'dates.value', 'matchedPhrases' => '2022' },
-                           { 'matchedField' => 'contributors.value', 'matchedPhrases' => 'Jane Datascientist' }] }
+                           { 'matchedField' => 'contributors.value', 'matchedPhrases' => 'Jane Datascientist' },
+                           { 'matchedField' => 'source', 'matchedPhrases' => 'mit archivesspace' }] }
     assert_empty trim_highlights(result)
   end
 
@@ -21,7 +22,8 @@ class SearchHelperTest < ActionView::TestCase
     result = { highlight: [{ 'matchedField' => 'title', 'matchedPhrases' => 'Very important data' },
                            { 'matchedField' => 'content_type', 'matchedPhrases' => 'Dataset' },
                            { 'matchedField' => 'numbering', 'matchedPhrases' => '2022' },
-                           { 'matchedField' => 'notes', 'matchedPhrases' => 'Datascientist, Jane' }] }
+                           { 'matchedField' => 'notes', 'matchedPhrases' => 'Datascientist, Jane' },
+                           { 'matchedField' => 'source', 'matchedPhrases' => 'mit archivesspace' }] }
     assert_equal [{ 'matchedField' => 'numbering', 'matchedPhrases' => '2022' },
                   { 'matchedField' => 'notes', 'matchedPhrases' => 'Datascientist, Jane' }], trim_highlights(result)
   end