fix(ai-chat): stop the reasoning-stream hang — parse markdown only when expanded (#302) #303

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Author	SHA1	Message	Date
agent_coder	2d30ad1fa2	fix(ai-chat): parse reasoning markdown only while expanded to stop the thinking-stream hang (#302 ) The reasoning block memoized its markdown render on [trimmed] alone, so as the reasoning text streamed in it re-parsed the whole, ever-growing text (marked + DOMPurify) on every throttled delta (~20Hz) — an O(n^2) CPU storm that pinned the main thread and froze the chat during a long "thinking" phase. Worse, the block is collapsed by default, so all that parsing was for a hidden body the user never sees (html is only shown inside <Collapse in={open}>). Gate the parse on `open`: collapsed shows the cheap raw-text fallback and does no markdown parsing; expanding parses the current text once (an instant user click), and further streaming while open is the normal per-delta append render, like the answer. Test: assert renderChatMarkdown is not called while collapsed and is called once on expand. closes #302 Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>	2026-07-03 05:01:37 +03:00

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2d30ad1fa2

fix(ai-chat): parse reasoning markdown only while expanded to stop the thinking-stream hang (#302 )

The reasoning block memoized its markdown render on [trimmed] alone, so as the
reasoning text streamed in it re-parsed the whole, ever-growing text (marked +
DOMPurify) on every throttled delta (~20Hz) — an O(n^2) CPU storm that pinned the
main thread and froze the chat during a long "thinking" phase. Worse, the block is
collapsed by default, so all that parsing was for a hidden body the user never sees
(html is only shown inside <Collapse in={open}>).

Gate the parse on `open`: collapsed shows the cheap raw-text fallback and does no
markdown parsing; expanding parses the current text once (an instant user click), and
further streaming while open is the normal per-delta append render, like the answer.

Test: assert renderChatMarkdown is not called while collapsed and is called once on
expand.

closes #302

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

2026-07-03 05:01:37 +03:00

fix(ai-chat): stop the reasoning-stream hang — parse markdown only when expanded (#302) #303

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