Story (Required)

• Add end-to-end (e2e) tests for the progressive sync feature in upstream. While investigating deletion order issues, it became clear that no e2e tests currently exist for this alpha feature. This story aims to fill that critical testing gap to ensure the progressive sync feature's stability and correctness, especially as it moves towards broader adoption.
• As an engineer working on the progressive sync feature, I want comprehensive end-to-end tests for progressive sync, so that I can confidently verify its behavior across various scenarios, prevent regressions, and ensure data integrity.

Background and Approach (Required)

• During recent work on deletion order, a significant gap was identified: the complete absence of end-to-end tests for this feature. This lack of e2e coverage makes it challenging to validate the entire flow, detect subtle bugs or regressions introduced during development, and confidently evolve the feature. Without these tests, we risk deploying issues that could lead to unexpected behavior for users.
• The approach for this story is to establish a foundational set of e2e tests for progressive sync. This will involve:

Scenario Identification: Defining core e2e scenarios for progressive sync that can be tested.

Test Environment Preparation: setting up a dedicated test environment that closely mimics the actual deployment environment for progressive sync, allowing for realistic testing. And integrating these new tests into our existing e2e test framework 

Can use sync waves test - https://github.com/argoproj/argo-cd/blob/master/test/e2e/sync_waves_test.go as a guide.

Out of Scope

• Downstream e2e tests for progressive sync
• Performance, load, or stress testing of progressive sync.
• Refactoring or redesign of the progressive sync feature's core logic.
• Adding unit or integration tests for specific components of progressive sync (this story focuses on the end-to-end flow).

Dependencies

• No dependecies

Acceptance Criteria (Mandatory)

• upstream has e2e tests added here - https://github.com/argoproj/argo-cd/tree/master/test/e2e 

Definition of Done

• Code Complete:
  • All code has been written, reviewed, and approved.
• Tested:
  • Unit tests have been written and passed.
  • Ensure code coverage is not reduced with the changes.
  • Integration tests have been automated.
  • System tests have been conducted, and all critical bugs have been fixed.
  • Tested and merged on OpenShift either upstream or downstream on a local build.
• Documentation:
  • User documentation or release notes have been written (if applicable).
• Build:
  • Code has been successfully built and integrated into the main repository / project.
  • Midstream changes (if applicable) are done, reviewed, approved and merged.
• Review:
  • Code has been peer-reviewed and meets coding standards.
  • All acceptance criteria defined in the user story have been met.
  • Tested by reviewer on OpenShift.
• Deployment:
  • The feature has been deployed on OpenShift cluster for testing.