fix: prevent enqueuing into closed ReadableStream

[CodeMan62]

Closes #1751

✅ Checklist

• I have followed every step in the contributing guide
• The PR title follows the convention.
• I ran and tested the code works

---

Testing

1. Ran package tests using:

pnpm run test --filter @trigger.dev/core

2. Verified that the ReadableStream properly handles closure states
3. Confirmed that the stream cleanup works as expected
4. Tested the realtime runs functionality to ensure no errors after extended periods

---

Changelog

• Added #isStreamClosed flag to track stream state
• Added checks to prevent enqueueing data after stream closure
• Improved stream cleanup in the cancel handler
• Enhanced error handling to properly mark stream as closed
• Added proper cleanup of resources in stop() method
• Fixed the "Cannot enqueue a chunk into a closed readable stream" error that occurred after 5-15 minutes

---

Screenshots

N/A - This is a backend fix for stream handling, no UI changes.

💯

Summary by CodeRabbit

• Bug Fixes

  • Improved streaming reliability by ensuring that no additional messages are processed once a stream is stopped or canceled.
  • Enhanced error handling, resulting in a more stable and predictable streaming experience.

• Refactor

  • Optimized stream lifecycle management for improved performance and consistency.

[changeset-bot]

⚠️ No Changeset found

Latest commit: 0967cad

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[coderabbitai]

Walkthrough

The changes add a private boolean property #isStreamClosed to the ReadableShapeStream class to track the state of the stream. The stop, cancel, and transform methods have been modified to check or update this flag, ensuring no further message processing occurs when the stream is closed. Error handling in the transform method now wraps processing logic in a try-catch block, logging errors and calling an error handler that also sets the stream to a closed state and unsubscribes from the stream.

Changes

File Path	Change Summary
packages/core/.../apiClient/stream.ts	Added a private boolean property #isStreamClosed. Modified the stop, cancel, and transform methods to check/update this flag, and enhanced error handling with a try-catch block that logs errors and unsubscribes via the error handler.

Sequence Diagram(s)

Loading

sequenceDiagram
    participant C as Client
    participant S as ReadableShapeStream
    participant U as Unsubscribe
    participant EH as ErrorHandler

    C->>S: stop()
    S->>S: set #isStreamClosed = true
    S->>U: call unsubscribe function

    C->>S: cancel()
    S->>S: set #isStreamClosed = true
    S->>U: call unsubscribe function

    S->>S: transform(message)
    alt Stream Open
        S->>S: Process message
    else Stream Closed
        S->>S: Skip processing
    end

    S->>S: Error in transform
    alt Error Caught
        S->>EH: invoke error handler
        S->>U: call unsubscribe function
    end

Poem

I'm a rabbit with a happy beat,
In code streams, I'm light on my feet.
When the stream is closed, I hop away,
Unsubscribing troubles, safe and gray.
Errors caught keep my trail so neat!
🐰✨

Warning

There were issues while running some tools. Please review the errors and either fix the tool’s configuration or disable the tool if it’s a critical failure.

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Scope: all 2 workspace projects
 ERR_PNPM_OPTIONAL_DEPS_REQUIRE_PROD_DEPS  Optional dependencies cannot be installed without production dependencies

---

📜 Recent review details

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Review profile: CHILL
Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 6cf86d5 and e56bc39.

📒 Files selected for processing (1)

• packages/core/src/v3/apiClient/stream.ts (3 hunks)

🔇 Additional comments (8)

packages/core/src/v3/apiClient/stream.ts (8)

92-92: Excellent addition of a stream state tracking flag.

The new #isStreamClosed boolean property is a clean solution for tracking the stream's closed state. This will serve as the foundation for preventing data from being enqueued into a closed ReadableStream.

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94-97: Good implementation in the stop method.

Setting the #isStreamClosed flag to true before calling the unsubscribe function ensures that no further messages will be processed after stopping the stream, which properly addresses the issue of enqueueing into a closed stream.

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106-110: Critical fix to prevent enqueueing after stream closure.

This check prevents the controller from enqueueing messages when the stream is closed, directly addressing the "Cannot enqueue a chunk into a closed readable stream" error mentioned in the PR objectives.

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114-117: Proper resource cleanup in cancel handler.

The updated cancel method now sets the stream as closed and calls the unsubscribe function, ensuring proper cleanup when the consumer cancels the stream. This prevents potential memory leaks and lingering connections.

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123-125: Effective early check for closed stream state.

This early return pattern efficiently prevents unnecessary message processing when the stream is already closed, improving performance and preventing potential errors.

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127-170: Robust error handling with try-catch implementation.

Wrapping the message processing logic in a try-catch block improves error resilience. The error handling appropriately logs the error and calls the error handler, ensuring that errors during processing don't crash the application and are properly handled.

---

158-165: Additional safety check before enqueueing rows.

While this check might seem redundant with the early return at lines 123-125, it provides an extra layer of protection specifically for the row enqueueing process. This defensive programming approach ensures that even if the stream becomes closed during message processing, no rows will be enqueued.

---

214-215: Complete cleanup on error.

Setting #isStreamClosed to true and calling unsubscribe in the error handler ensures proper cleanup when errors occur. This prevents resource leaks and further attempts to enqueue data after an error has occurred.

✨ Finishing Touches

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[coderabbitai]

🧩 Analysis chain

I'll review this PR for you. Let me gather more information about the changes first.

---

🏁 Script executed:

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# Get the PR diff to examine the changes
git diff HEAD^ HEAD

Length of output: 209

---

I need to first check out the PR to properly review the changes. Let me try again.

---

🏁 Script executed:

#!/bin/bash
# First, let's check if we can fetch the PR
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Length of output: 272

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# Let's also check what files were changed in the PR
git diff --name-only HEAD~1 HEAD

# Now, let's look at the specific file mentioned in the summary
cat packages/core/src/v3/apiClient/stream.ts

Length of output: 6943

---

@CodeMan62: Yes, this PR looks excellent. The changes properly address the issue of enqueueing data into closed ReadableStreams by:

1. Adding the #isStreamClosed flag to track stream state
2. Adding appropriate checks before enqueueing data
3. Ensuring the flag is set to true in all necessary places (stop(), cancel handler, error handler)
4. Improving error handling with proper stream closure

These changes will effectively prevent the "Cannot enqueue a chunk into a closed readable stream" error that was occurring after 5-15 minutes of operation.

✅ Actions performed

Comments resolved.

[CodeMan62]

@ericallam can you check this PR and tell me if there is any problem in it