Fix chat composer height race during sidebar open transition#218
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The composer textarea had `flex: 1 1 auto` in a column flex container. When the sidebar panel reopened (CSS transition from width 0 → 320px), React mounted the DraftChatPanel and the auto-resize useLayoutEffect fired while the panel was still near-zero width. Setting height to `auto` let flex-grow expand the textarea to fill the degenerate layout, and scrollHeight captured that inflated value (e.g. 392px instead of 72px). The inline height then persisted after the transition completed. Changing to `flex: 0 0 auto` is safe because the JS auto-resize in ChatComposer already handles all height changes — flex-grow on the textarea was redundant and only harmful during transitions. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
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Summary
flex: 1 1 auto→flex: 0 0 autoon.composer-input— the JS auto-resize handles all height changes, so flex-grow was redundantRoot cause
When the sidebar panel reopens, the CSS
flex-basistransition starts from 0. React mountsDraftChatPaneland theuseLayoutEffectinChatComposerfires while the panel is still at ~0 width. Settingel.style.height = 'auto'during reflow letsflex-grow: 1expand the textarea to fill the available column height (degenerate layout at 0 width). The resultingscrollHeight(e.g. 392px) gets locked in as the inline height and persists after the transition completes.Test plan
🤖 Generated with Claude Code