FIX: Missing action to trigger add group members modal for group owners.

https://meta.discourse.org/t/unable-to-add-members-to-a-group-as-group-owner-who-is-not-staff/85346?u=tgxworld

app/assets/javascripts/discourse/templates/group-index.hbs

@@ -10,6 +10,7 @@
           showBulkAddModal="showBulkAddModal"}}
     {{else}}
       {{d-button icon="plus"
+          action="showAddMembersModal"
           label="groups.add_members.title"
           class="group-members-add"}}
     {{/if}}

test/javascripts/acceptance/group-index-test.js.es6

@@ -1,4 +1,4 @@
-import { acceptance, logIn } from "helpers/qunit-helpers";
+import { acceptance, logIn, replaceCurrentUser } from "helpers/qunit-helpers";
 
 acceptance("Group Members");
 
@@ -22,6 +22,22 @@ QUnit.test("Viewing Members as anon user", assert => {
   });
 });
 
+QUnit.test("Viewing Members as a group owner", assert => {
+  logIn();
+  Discourse.reset();
+  replaceCurrentUser({ admin: false, staff: false });
+
+  visit("/groups/discourse");
+  click('.group-members-add');
+
+  andThen(() => {
+    assert.equal(
+      find('#group-add-members-user-selector').length, 1,
+      'it should display the add members modal'
+    );
+  });
+});
+
 QUnit.test("Viewing Members as an admin user", assert => {
   logIn();
   Discourse.reset();