HTML search: Ensure that checkRanking fails when the final entry …

…is not found (#12608)

The ``checkRanking`` function in our test suite has a bug; it's currently possible for the final item in the expected ranking list *not* to be found in the result-set, and yet for the function to pass.

**Expected Behaviour**
The ``checkRanking`` function should confirm that all of the items specified in the ``expectedRanking`` argument appear within the ``results`` argument, and in the list-iteration-order provided.  If they do not, then an assertion error should be raised, failing the test.

**Actual Behaviour**
If all items up until the final entry in the ``expectedRanking`` argument are found in the expected order, but the final entry itself is not found at all in the ``results``, then no assertion error is raised, and the test passes.

tests/js/searchtools.js

@@ -22,6 +22,7 @@ describe('Basic html theme search', function() {
     }
 
     expect(remainingItems.length).toEqual(0);
+    expect(nextExpected).toEqual(undefined);
   }
 
   describe('terms search', function() {
@@ -137,7 +138,7 @@ describe('Basic html theme search', function() {
 
       expectedRanking = [
         ['relevance', 'Relevance', ''],  /* main title */
-        ['index', 'relevance.Example.relevance', '#module-relevance'],  /* py:class attribute */
+        ['index', 'relevance.Example.relevance', '#relevance.Example.relevance'],  /* py:class attribute */
       ];
 
       searchParameters = Search._parseQuery('relevance');