<!--IssueSummary start--> <details> <summary> Everyone can contribute. [Help move this issue forward](https://handbook.gitlab.com/handbook/marketing/developer-relations/contributor-success/community-contributors-workflows/#contributor-links) while earning points, leveling up and collecting rewards. </summary> - [Work on this issue](https://contributors.gitlab.com/manage-issue?action=work&projectId=278964&issueIid=388354) - [Close this issue](https://contributors.gitlab.com/manage-issue?action=close&projectId=278964&issueIid=388354) </details> <!--IssueSummary end--> This issue came out of this discussion https://gitlab.com/gitlab-org/gitlab/-/issues/384226#note_1241527987. When the GitLab for Slack app is completely uninstalled from a workspace we should purge all related Slack-related data (`ChatName`, `SlackIntegration` at time of writing). We would subscribe to the `app_uninstalled` event https://api.slack.com/events/app_uninstalled and handle it within `Integrations::SlackEventService`. This request was also made by the Slack app Review team on 24 Jan 2023: > It looks like when the app is currently uninstalled, the connection still remains within the web app. I believe this can be handled by subscribing to the `app_uninstalled` event, mentioned here: https://api.slack.com/events/app_uninstalled. ### Availability & Testing Risks include * Accidentally purging a ChatName for a different workspace * Accidentally leaving orphaned project integrations Suggestions: * feature tests that mock the Slack subscription and validate that the above do not happen. <!-- This section needs to be retained and filled in during the workflow planning breakdown phase of this feature proposal, if not earlier. What risks does this change pose to our availability? How might it affect the quality of the product? What additional test coverage or changes to tests will be needed? Will it require cross-browser testing? Please list the test areas (unit, integration and end-to-end) that needs to be added or updated to ensure that this feature will work as intended. Please use the list below as guidance. * Unit test changes * Integration test changes * End-to-end test change See the Quality Engineering quad planning and test planning processes and reach out to your counterpart Software Engineer in Test for assistance. Quad Planning: https://about.gitlab.com/handbook/engineering/quality/quality-engineering/quad-planning Test Planning: https://about.gitlab.com/handbook/engineering/quality/quality-engineering/test-engineering/#test-planning -->