Use helper method to set filtered search input attributes

The list of attributes for the filtered search input was getting long, so use a
helper method to fill that hash.

Also, for multiple issue assignees, a helper is more convenient because it would
allow EE to override the behavior if MIA is supported.

app/assets/javascripts/filtered_search/filtered_search_token_keys_issues_ee.js

@@ -26,9 +26,11 @@ class FilteredSearchTokenKeysIssuesEE extends gl.FilteredSearchTokenKeys {
   static get() {
     const tokenKeys = Array.from(super.get());
 
-    // Enable multiple assignees
-    const assigneeTokenKey = tokenKeys.find(tk => tk.key === 'assignee');
-    if (this.availableFeatures && this.availableFeatures.multipleAssignees) assigneeTokenKey.type = 'array';
+    // Enable multiple assignees when available
+    if (this.availableFeatures && this.availableFeatures.multipleAssignees) {
+      const assigneeTokenKey = tokenKeys.find(tk => tk.key === 'assignee');
+      assigneeTokenKey.type = 'array';
+    }
 
     tokenKeys.push(weightTokenKey);
     return tokenKeys;

app/helpers/ee/search_helper.rb

+module EE
+  module SearchHelper
+    def search_filter_input_options(type)
+      options = super
+      options[:data][:'multiple-assignees'] = 'true' if (type == :issues) && @project.feature_available?(:multiple_issue_assignees)
+
+      options
+    end
+  end
+end

app/helpers/search_helper.rb

 module SearchHelper
+  prepend EE::SearchHelper
+
   def search_autocomplete_opts(term)
     return unless current_user
 
@@ -134,6 +136,18 @@ module SearchHelper
     search_path(options)
   end
 
+  def search_filter_input_options(type)
+    {
+      id: "filtered-search-#{type}",
+      placeholder: 'Search or filter results...',
+      data: {
+        'project-id' => @project.id,
+        'username-params' => @users.to_json(only: [:id, :username]),
+        'base-endpoint' => project_path(@project)
+      }
+    }
+  end
+
   # Sanitize a HTML field for search display. Most tags are stripped out and the
   # maximum length is set to 200 characters.
   def search_md_sanitize(object, field)

app/views/shared/issuable/_search_bar.html.haml

 - type = local_assigns.fetch(:type)
 - board = local_assigns.fetch(:board, nil)
 - block_css_class = type != :boards_modal ? 'row-content-block second-block' : ''
-- can_multiple_assignees = @project.feature_available?(:"multiple_#{type.to_s}_assignees")
 
 .issues-filters
   .issues-details-filters.filtered-search-block{ class: block_css_class, "v-pre" => type == :boards_modal }
@@ -28,7 +27,7 @@
             .scroll-container
               %ul.tokens-container.list-unstyled
                 %li.input-token
-                  %input.form-control.filtered-search{ id: "filtered-search-#{type.to_s}", placeholder: 'Search or filter results...', data: { 'project-id' => @project.id, 'username-params' => @users.to_json(only: [:id, :username]), 'base-endpoint' => project_path(@project), 'multiple-assignees' => can_multiple_assignees } }
+                  %input.form-control.filtered-search{ search_filter_input_options(type) }
               = icon('filter')
             #js-dropdown-hint.filtered-search-input-dropdown-menu.dropdown-menu.hint-dropdown
               %ul{ data: { dropdown: true } }

spec/javascripts/filtered_search/filtered_search_token_keys_with_weights_spec.js → spec/javascripts/filtered_search/filtered_search_token_keys_issues_ee_spec.js

@@ -15,6 +15,9 @@ import '~/filtered_search/filtered_search_token_keys_issues_ee';
       let tokenKeys;
 
       beforeEach(() => {
+        gl.FilteredSearchTokenKeysIssuesEE.init({
+          multipleAssignees: true,
+        });
         tokenKeys = gl.FilteredSearchTokenKeysIssuesEE.get();
       });