use ids instead of role names for course roster filtering

test plan:
* create a custom course role
* delete it
* create another custom course role with the exact same name
* invite people into a course with that role
* should be able to select the role from the drop-down on the
 people page and find people

refs #CNVS-18343

Change-Id: I7f62d76984af1d92179d3541b03e41801c53327c
Reviewed-on: https://gerrit.instructure.com/48486
Reviewed-by: Dan Minkevitch <dan@instructure.com>
Product-Review: Dan Minkevitch <dan@instructure.com>
Tested-by: Jenkins
QA-Review: Jahnavi Yetukuri <jyetukuri@instructure.com>

app/views/jst/courses/roster/index.handlebars

@@ -18,7 +18,7 @@
     >
 
     <select
-      name="enrollment_role"
+      name="enrollment_role_id"
       data-view="roleSelect"
       aria-label='{{#t "role_to_search"}}Limit search to role{{/t}}'
       ></select>

app/views/jst/courses/roster/roleSelect.handlebars

@@ -1,6 +1,6 @@
 <option value="">{{#t "all_roles"}}All Roles{{/t}}</option>
     {{#each roles}}
-    <option value="{{name}}" {{#ifEqual name ../selectedRole}} selected="selected" {{/ifEqual}}>{{label}} ({{count}})</option>
+    <option value="{{id}}" {{#ifEqual id ../selectedRole}} selected="selected" {{/ifEqual}}>{{label}} ({{count}})</option>
     {{/each}}
 
 

spec/selenium/people_spec.rb

@@ -330,4 +330,23 @@ describe "people" do
       is_checked('#limit_privileges_to_course_section') == true
     end
   end
+
+  it "should filter by role ids" do
+    account_model
+    course_with_teacher_logged_in(:account => @account)
+    old_role = custom_student_role("Role")
+    old_role.deactivate!
+
+    new_role = @account.roles.new(:name => old_role.name)
+    new_role.base_role_type = "StudentEnrollment"
+    new_role.save!
+    new_role
+
+    student_in_course(:course => @course, :role => new_role, :name => "number2")
+
+    get "/courses/#{@course.id}/users"
+    click_option("select[name=enrollment_role_id]", new_role.id.to_s, :value)
+    wait_for_ajaximations
+    expect(ff('tr.rosterUser').count).to eq 1
+  end
 end