Add unit tests for models

**Feature request**
It would be great to have notifications for parsers.

**Use case**
Many users need this functionality for production deployments.

**Implementation idea**
Add a new config option `enable_notifications` with default `false`.

Start by locating the parser configuration and the existing model unit tests. Determine what parser notifications should report and how the enable_notifications option is expected to affect them, then add coverage for the default false behavior and the enabled path. The issue does not identify files or define the notification behavior, so clarification is needed before implementation.

Written by the indexing model from the issue text.