Add success banner when users are granted access to an app

This was a lot more complex than I'd hoped due to the difficulties in
cleanly distinguishing between a user having the Signin permission
granted vs having all permissions other than the Signin permission
removed.

I hope this is reasonably clear and duplication-free. I'd rather have
avoided passing the `granting_access` flag if possible and opting for
something slightly more extendable in future, but it won out over the
following alternative approaches:

1. Performing a lot of this logic in the view - harder to test, a bit
   too much duplication and adding too much logic to a rendering
   template.
2. Refactoring the `ApplicationPermissionsHelper` to support a new path
   for granting access - this had a lot of fairly complex branching
   logic in it and felt fairly geared towards "permissions" rather than
   "access" so I've opted against extending it further.

I've opted against writing controller tests for this behaviour. Although
we have some where we test for the presence of `flash[:application_id]`,
this feels a bit over the top, and I think it's sufficiently covered
with integration tests that are testing the view.

app/controllers/account/signin_permissions_controller.rb

@@ -7,6 +7,8 @@ def create
     params = { supported_permission_ids: current_user.supported_permissions.map(&:id) + [application.signin_permission.id] }
     UserUpdate.new(current_user, params, current_user, user_ip_address).call
 
+    flash[:application_id] = application.id
+    flash[:granting_access] = true
     redirect_to account_applications_path
   end
 

app/controllers/users/signin_permissions_controller.rb

@@ -10,6 +10,8 @@ def create
     params = { supported_permission_ids: @user.supported_permissions.map(&:id) + [application.signin_permission.id] }
     UserUpdate.new(@user, params, current_user, user_ip_address).call
 
+    flash[:application_id] = application.id
+    flash[:granting_access] = true
     redirect_to user_applications_path(@user)
   end
 

app/helpers/application_access_helper.rb

@@ -0,0 +1,10 @@
+module ApplicationAccessHelper
+  def access_granted_message(application_id, user = current_user)
+    application = Doorkeeper::Application.find_by(id: application_id)
+    return nil unless application
+
+    return "You have been granted access to #{application.name}." if user == current_user
+
+    "#{user.name} has been granted access to #{application.name}."
+  end
+end

app/helpers/success_alert_helper.rb

@@ -0,0 +1,15 @@
+module SuccessAlertHelper
+  def access_and_permissions_granted_params(application_id, granting_access:, user: current_user)
+    if granting_access
+      {
+        message: "Access granted",
+        description: access_granted_message(application_id, user),
+      }
+    else
+      {
+        message: "Permissions updated",
+        description: message_for_success(application_id, user),
+      }
+    end
+  end
+end

app/views/account/applications/index.html.erb

@@ -18,10 +18,9 @@
 
 <% if flash[:application_id] %>
   <% content_for(:custom_alerts) do %>
-    <%= render "govuk_publishing_components/components/success_alert", {
-        message: "Permissions updated",
-        description: message_for_success(flash[:application_id]),
-    } %>
+    <%= render "govuk_publishing_components/components/success_alert",
+      access_and_permissions_granted_params(flash[:application_id], granting_access: flash[:granting_access])
+    %>
   <% end %>
 <% end %>
 

app/views/users/applications/index.html.erb

@@ -23,11 +23,9 @@
 
 <% if flash[:application_id] %>
   <% content_for(:custom_alerts) do %>
-    <%= render "govuk_publishing_components/components/success_alert", {
-        message: "Permissions updated",
-        description: message_for_success(flash[:application_id], @user),
-    } %>
-  <% end %>
+    <%= render "govuk_publishing_components/components/success_alert",
+      access_and_permissions_granted_params(flash[:application_id], granting_access: flash[:granting_access], user: @user)
+    %>  <% end %>
 <% end %>
 
 <%= render "components/table", {

test/helpers/application_access_helper_test.rb

@@ -0,0 +1,29 @@
+require "test_helper"
+
+class ApplicationAccessHelperTest < ActionView::TestCase
+  setup do
+    @application = create(:application, name: "Whitehall")
+    stubs(:current_user).returns(create(:user))
+  end
+
+  context "#access_granted_message" do
+    context "when the user is setting their own permissions" do
+      should "return a message informing them that they have access to an application" do
+        assert_equal "You have been granted access to Whitehall.", access_granted_message(@application)
+      end
+    end
+
+    context "when the user is setting another's permissions" do
+      should "return a message informing them that the other user have access to an application" do
+        user = create(:user, name: "Gerald")
+        assert_equal "Gerald has been granted access to Whitehall.", access_granted_message(@application, user)
+      end
+    end
+
+    context "when the application does not exist" do
+      should "return nil" do
+        assert_nil access_granted_message(:made_up_id)
+      end
+    end
+  end
+end

test/helpers/success_alert_helper_test.rb

@@ -0,0 +1,28 @@
+require "test_helper"
+
+class SuccessAlertHelperTest < ActionView::TestCase
+  context "#access_and_permissions_granted_params" do
+    setup do
+      @application = create(:application)
+      stubs(:current_user).returns(create(:user))
+    end
+
+    context "when granting access" do
+      should "return success alert params with the `access_granted_message` text" do
+        stubs(:access_granted_message).returns("Granted access")
+
+        expected = { message: "Access granted", description: "Granted access" }
+        assert_equal expected, access_and_permissions_granted_params(@application.id, granting_access: true)
+      end
+    end
+
+    context "when updating permissions" do
+      should "return success alert params with the `message_for_success` text" do
+        stubs(:message_for_success).returns("Added permissions")
+
+        expected = { message: "Permissions updated", description: "Added permissions" }
+        assert_equal expected, access_and_permissions_granted_params(@application.id, granting_access: false)
+      end
+    end
+  end
+end

test/support/granting_access_helpers.rb

@@ -29,6 +29,9 @@ def assert_grant_access(application, grantee, grantee_is_self: false)
 
     assert app_with_access_table.has_content?(application.name)
     assert grantee.has_access_to?(application)
+    success_banner_caption = grantee_is_self ? "You have been granted access to #{application.name}." : "#{grantee.name} has been granted access to #{application.name}."
+    assert_flash_content("Access granted")
+    assert_flash_content(success_banner_caption)
   end
 
   def refute_grant_access(application)