added hint for multiline triple backtick code block detector

[ekang7]

Issue #, if available:
#3271

Description of changes:
Since the triple backtick detector results in unexpected hangs, I added a multiline hint when an unclosed triple backtick is present in the user prompt. I also made it so that the hint will not be incorrectly used for autocompletion.

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[evanliu048]

This is expected behavior, not a bug. When the user types ``` and presses Enter, the validator correctly treats it as an unclosed code block and returns Incomplete, moving the cursor to the next line to wait for input. I don’t currently see a strong reason to remove this check

[ekang7]

I think we may then need to update the documentation because right now
https://docs.aws.amazon.com/amazonq/latest/qdeveloper-ug/command-line-chat-commands.html
doesn't include anything about triple backticks. We could also continue with the removal as users have other ways of doing multilines and sometimes if a user copies and pastes something with a single ```, this could result in unexpected behavior

[evanliu048]

I think we may then need to update the documentation because right now https://docs.aws.amazon.com/amazonq/latest/qdeveloper-ug/command-line-chat-commands.html doesn't include anything about . We could also continue with the removal as users have other ways of doing multilines and sometimes if a user copies and pastes something with a single , this could result in unexpected behavior

The documentation you pointed to covers commands, while ``` isn’t a command — it’s just a syntax check. So it’s expected that it doesn’t appear there.

That said, from a usability perspective, I agree we could improve the experience. Instead of silently waiting for the closing code fence, we might consider showing a hint when the user opens a code block — something like a clear UI indicator that Q is now in multiline mode and waiting for the closing backticks. That would avoid confusion when users forget to close the block

[ekang7]

Sounds good! I'll use the greyed out version of the hint text like in the attached screenshot to say something like "in multiline mode, waiting for closing backticks ```" when there are opening backticks but not closing backticks

[ekang7]

I have successfully added the multiline hint

[evanliu048]

I have successfully added the multiline hint

I like the UX improvement! One concern though: pressing → (right arrow) currently fills in "in multiline mode, waiting for closing backticks ```" as input text. This seems unintended since it's a status hint, not a completion suggestion

[ekang7]

Thank you! Good point, I made it so that the hint will not be used as part of an autocompletion suggestion any longer.