Move permissions_for to PermissionsHelper

In preparation for using this helper in the /account pages.

There's nothing specific to batch invitations in this method and moving
it won't break any existing functionality because we currently include
all helpers into every view.

app/helpers/batch_invitation_permissions_helper.rb

@@ -6,11 +6,4 @@ def formatted_permission_name(application_name, permission_name)
       permission_name
     end
   end
-
-  def permissions_for(application)
-    all_permissions = application.supported_permissions.grantable_from_ui
-    signin, others = all_permissions.partition(&:signin?)
-
-    signin + others.sort_by(&:name)
-  end
 end

app/helpers/permissions_helper.rb

@@ -0,0 +1,8 @@
+module PermissionsHelper
+  def permissions_for(application)
+    all_permissions = application.supported_permissions.grantable_from_ui
+    signin, others = all_permissions.partition(&:signin?)
+
+    signin + others.sort_by(&:name)
+  end
+end

test/helpers/batch_invitation_permissions_helper_test.rb

@@ -10,29 +10,4 @@ class BatchInvitationPermissionsHelperTest < ActionView::TestCase
       assert_equal "Has access to Whitehall?", formatted_permission_name("Whitehall", SupportedPermission::SIGNIN_NAME)
     end
   end
-
-  context "#permissions_for" do
-    should "return all of the supported permissions that are grantable from the ui" do
-      application = create(:application,
-                           name: "Whitehall",
-                           with_supported_permissions: ["Editor", SupportedPermission::SIGNIN_NAME],
-                           with_supported_permissions_not_grantable_from_ui: ["Not grantable"])
-
-      permission_names = permissions_for(application).map(&:name)
-
-      assert permission_names.include?("Editor")
-      assert permission_names.include?(SupportedPermission::SIGNIN_NAME)
-      assert_not permission_names.include?("Not grantable")
-    end
-
-    should "sort the permissions alphabetically by name, but with the signin permission first" do
-      application = create(:application,
-                           name: "Whitehall",
-                           with_supported_permissions: ["Writer", "Editor", SupportedPermission::SIGNIN_NAME])
-
-      permission_names = permissions_for(application).map(&:name)
-
-      assert_equal [SupportedPermission::SIGNIN_NAME, "Editor", "Writer"], permission_names
-    end
-  end
 end

test/helpers/permissions_helper_test.rb

@@ -0,0 +1,28 @@
+require "test_helper"
+
+class PermissionsHelperTest < ActionView::TestCase
+  context "#permissions_for" do
+    should "return all of the supported permissions that are grantable from the ui" do
+      application = create(:application,
+                           name: "Whitehall",
+                           with_supported_permissions: ["Editor", SupportedPermission::SIGNIN_NAME],
+                           with_supported_permissions_not_grantable_from_ui: ["Not grantable"])
+
+      permission_names = permissions_for(application).map(&:name)
+
+      assert permission_names.include?("Editor")
+      assert permission_names.include?(SupportedPermission::SIGNIN_NAME)
+      assert_not permission_names.include?("Not grantable")
+    end
+
+    should "sort the permissions alphabetically by name, but with the signin permission first" do
+      application = create(:application,
+                           name: "Whitehall",
+                           with_supported_permissions: ["Writer", "Editor", SupportedPermission::SIGNIN_NAME])
+
+      permission_names = permissions_for(application).map(&:name)
+
+      assert_equal [SupportedPermission::SIGNIN_NAME, "Editor", "Writer"], permission_names
+    end
+  end
+end