Add count to search field placeholder

ui/app/templates/optimize.hbs

@@ -7,7 +7,7 @@
             <SearchBox
               data-test-recommendation-summaries-search
               @searchTerm={{mut this.searchTerm}}
-              @placeholder="Search recommendations..." />
+              @placeholder="Search {{this.model.length}} {{pluralize "recommendation" this.model.length}}..." />
           {{/if}}
         </div>
         <div class="toolbar-item is-right-aligned is-mobile-full-width">

ui/tests/acceptance/optimize-test.js

@@ -383,6 +383,8 @@ module('Acceptance | optimize search and facets', function(hooks) {
 
     await Optimize.visit();
 
+    assert.equal(Optimize.search.placeholder, `Search ${Optimize.recommendationSummaries.length} recommendations...`);
+
     await Optimize.search.fillIn('ooo');
 
     assert.equal(Optimize.recommendationSummaries.length, 2);

ui/tests/pages/optimize.js

@@ -26,6 +26,7 @@ export default create({
 
   search: {
     scope: '[data-test-recommendation-summaries-search] input',
+    placeholder: attribute('placeholder'),
   },
 
   card: recommendationCard,