fix: preserve prompt text when cancelling streaming

[Nixxx19]

Summary

Fixes issue #13387 where pressing Escape to cancel streaming would delete any newly entered prompt text. The fix ensures prompts are never removed when cancelling, preserving user-entered text regardless of content.

Details

Previously, when cancelling streaming (onCancelSubmit(false)), the buffer was always cleared to an empty string, even if the user had typed new text. This was frustrating because users would type a new prompt while waiting for a response, then lose it when pressing Escape.

The fix changes the cancellation logic to never modify the buffer when cancelling - it simply returns early, preserving whatever text the user has typed, pasted, or restored. This aligns with the principle that users are in control of their prompts.

Changes:

• Modified cancelHandlerRef in AppContainer.tsx to return early when shouldRestorePrompt=false, never touching the buffer
• Updated existing test to reflect new behavior (buffer preserved even when empty)
• Added regression test to verify prompt text is preserved when cancelling, even if it matches the last message

Related Issues

Fixes #13387

How to Validate

1. Start a query that streams (e.g., "What is Python?")
2. While it's streaming, type a new prompt (e.g., "Tell me about JavaScript")
3. Press Escape once to cancel streaming
4. Expected: The new prompt text should remain visible (not disappear)
5. Also test: Type the same prompt as your last message, press Escape - it should still be preserved

Edge cases to verify:

• Empty buffer + Escape → buffer stays empty (not cleared)
• Buffer with text + Escape → text preserved
• Buffer with same text as last message + Escape → text preserved

Pre-Merge Checklist

• Updated relevant documentation and README (if needed)
• Added/updated tests (if needed)
• Noted breaking changes (if any) - None
• Validated on required platforms/methods:
  • MacOS
    • npm run
    • npx
    • Docker
    • Podman
    • Seatbelt
  • Windows
    • npm run
    • npx
    • Docker
  • Linux
    • npm run
    • npx
    • Docker

[gemini-code-assist]

Summary of Changes

Hello, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request significantly improves the user experience by preventing the loss of user-typed prompt text when streaming operations are cancelled. Previously, cancelling a stream would inadvertently clear the input buffer, leading to frustration. The updated logic ensures that the user's input is always retained, giving them full control over their prompt regardless of streaming status.

Highlights

• Prompt Preservation on Cancel: Implemented a fix to ensure that newly entered prompt text is preserved when a user cancels streaming by pressing Escape, addressing issue Hitting Escape deletes newly entered prompt! #13387.
• Cancellation Logic Update: Modified the cancelHandlerRef in AppContainer.tsx to return early when shouldRestorePrompt is false, preventing the buffer from being cleared during cancellation.
• Test Coverage Enhanced: Updated an existing test case to reflect the new behavior of preserving the buffer even when empty, and added a new regression test to verify prompt text preservation when cancelling, including scenarios where the text matches the last message.

Changelog

• packages/cli/src/ui/AppContainer.test.tsx
  • Updated the description of a test case to accurately reflect that the buffer is preserved, not cleared, when cancelling with an empty buffer.
  • Added a new regression test to verify that prompt text remains preserved when cancelling streaming, even if the text is identical to the last message.
• packages/cli/src/ui/AppContainer.tsx
  • Introduced an early return in the cancelHandlerRef function when shouldRestorePrompt is false, ensuring the prompt buffer is not modified during cancellation.
  • Refined the condition for calling buffer.setText to only proceed when there is actual text to set, removing the redundant check for !shouldRestorePrompt.

Activity

• The pull request author, Nixxx19, has provided a detailed summary, outlining the problem, solution, and validation steps.
• The author has marked the relevant documentation and README as updated, and tests as added/updated, in the pre-merge checklist.

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[github-actions]

You already have 7 pull requests open. Please work on getting existing PRs merged before opening more.

[gemini-code-assist]

Code Review

This pull request addresses an issue where user input in the prompt is lost when cancelling a streaming response. The proposed fix correctly modifies the cancellation handler to preserve the text buffer, preventing data loss. The accompanying test changes validate the new behavior and include a regression test to prevent this issue in the future. The implementation is sound and effectively resolves the reported bug.

[Nixxx19]

@jacob314 the pr is ready for review, i have tested it the issue is solved by this pr, thanks for re opening!

[jacob314]

[Nixxx19]

hey @jacob314 @scidomino could you please rerun the failed job? It looks like a timeout issue unrelated to my changes. thanks!

[scidomino]

rerunning

[Nixxx19]

rerunning

thanks @scidomino @jacob314 !!