From 81d738d1de6e1dd8aec84660715719785ee931fc Mon Sep 17 00:00:00 2001
From: Ashit Rath <ashit@appsmith.com>
Date: Mon, 15 Jul 2024 22:34:27 +0530
Subject: [PATCH] chore: Buffer first eval action to fix race condition with
 setup worker (#34891)
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## Description
Check the issue description for the actual problem.

Solution:
To mitigate the race condition; instead of using `take` post setup
worker an `actionChannel` is used to create a queue to detect any first
eval action dispatched while the code path completes the worker setup.
This queue is then picked by and the action is processed and the
`actionChannel` is closed.

The baseline theory of the solution is to create a queue of any first
eval action dispatch throughout the lifecycle of the setup process but
act only when the setup is complete

The problem is not that evident in applications but in packages it's
highly reproducible as there are less api fetches to start eval

Fixes https://github.com/appsmithorg/appsmith/issues/34890

## Automation

/ok-to-test tags="@tag.All"

### :mag: Cypress test results
<!-- This is an auto-generated comment: Cypress test results  -->
> [!TIP]
> 🟢 🟢 🟢 All cypress tests have passed! 🎉 🎉 🎉
> Workflow run:
<https://github.com/appsmithorg/appsmith/actions/runs/9903341349>
> Commit: 999f677e9af9c1d90201fcf124d1246ecfd79ef2
> <a
href="https://internal.appsmith.com/app/cypress-dashboard/rundetails-65890b3c81d7400d08fa9ee5?branch=master&workflowId=9903341349&attempt=1"
target="_blank">Cypress dashboard</a>.
> Tags: `@tag.All`
> Spec:
> <hr>Fri, 12 Jul 2024 07:07:30 UTC
<!-- end of auto-generated comment: Cypress test results  -->


## Communication
Should the DevRel and Marketing teams inform users about this change?
- [ ] Yes
- [ ] No


<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

- **Bug Fixes**
- Improved reliability and performance of evaluation change listener by
optimizing action handling.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->
---
 app/client/src/sagas/EvaluationsSaga.ts | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/app/client/src/sagas/EvaluationsSaga.ts b/app/client/src/sagas/EvaluationsSaga.ts
index a81d24267f..302ec13d8a 100644
--- a/app/client/src/sagas/EvaluationsSaga.ts
+++ b/app/client/src/sagas/EvaluationsSaga.ts
@@ -646,6 +646,7 @@ function* evalAndLintingHandler(
 }
 
 function* evaluationChangeListenerSaga(): any {
+  const firstEvalActionChannel = yield actionChannel(FIRST_EVAL_REDUX_ACTIONS);
   // Explicitly shutdown old worker if present
   yield all([call(evalWorker.shutdown), call(lintWorker.shutdown)]);
   const [evalWorkerListenerChannel] = yield all([
@@ -669,8 +670,9 @@ function* evaluationChangeListenerSaga(): any {
   yield spawn(handleEvalWorkerRequestSaga, evalWorkerListenerChannel);
 
   const initAction: EvaluationReduxAction<unknown> = yield take(
-    FIRST_EVAL_REDUX_ACTIONS,
+    firstEvalActionChannel,
   );
+  firstEvalActionChannel.close();
 
   // Wait for widget config build to complete before starting evaluation only if the current editor is not a workflow
   const isCurrentEditorWorkflowType = yield select(