[FE Fix]: Keep evaluator chain connected on app-revision change

[ardaerzin]

Summary

tba...

Testing

Verified locally

Added or updated tests

QA follow-up

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• I have included a video or screen recording for UI changes, or marked Demo as N/A
• Relevant tests pass locally
• Relevant linting and formatting pass locally
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Project	Deployment	Actions	Updated (UTC)
agenta-documentation	Ready	Preview, Comment	May 29, 2026 6:19pm

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No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro Plus

Run ID: 40466567-738d-4ebb-959a-822df244a3e0

📥 Commits

Reviewing files that changed from the base of the PR and between a2df5cb and 752d3db.

📒 Files selected for processing (3)

• web/packages/agenta-playground/src/state/controllers/playgroundController.ts
• web/packages/agenta-playground/src/state/helpers/connectionGraph.ts
• web/packages/agenta-playground/tests/unit/connectionGraph.test.ts

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📝 Walkthrough

Summary by CodeRabbit

• Bug Fixes

  • Switching primary nodes now preserves valid downstream connections instead of clearing all connections. Invalid connections pointing to removed nodes are automatically cleaned up.

• Tests

  • Added unit test coverage for connection validation and pruning operations.

Walkthrough

This PR improves connection preservation when switching primary nodes in the Agenta Playground. A new pruneDanglingConnections utility filters output connections to those with valid endpoints, replacing the prior approach that cleared all connections on primary node swap. The controller imports and applies this helper to retain valid downstream connections while removing only those pointing to missing nodes.

Changes

Preserve Downstream Connections on Primary Node Switch

Layer / File(s)	Summary
Connection pruning utility and tests src/state/helpers/connectionGraph.ts, tests/unit/connectionGraph.test.ts	pruneDanglingConnections(connections, nodes) filters output connections to retain only those whose source and target node IDs both exist in the provided nodes array. Unit tests cover primary node in-place swap, missing source/target nodes, and empty inputs.
Primary node switching logic update src/state/controllers/playgroundController.ts	changePrimaryNodeAtom now imports and calls pruneDanglingConnections to preserve valid downstream connections when switching primary nodes, instead of unconditionally clearing all connections.

🎯 2 (Simple) | ⏱️ ~10 minutes

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 inconclusive)

Check name	Status	Explanation	Resolution
Description check	❓ Inconclusive	The description template is present but largely empty with 'tba...' placeholder, though the PR objectives provide context about the bug fix related to evaluator chain connectivity.	Complete the Summary section with a clear explanation of the problem being fixed and the solution implemented, rather than leaving it as 'tba...'.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly identifies the main change: preserving evaluator chain connections when the app-revision changes by keeping nodes connected on primary node switching.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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✨ Finishing Touches

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🧪 Generate unit tests (beta)

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• Commit unit tests in branch fe-fix/evaluator-chain-run-reliability

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Updated at 2026-05-29T18:27:29.095Z