From 1238efce135d211f260da6a2ab2d6400224ea03f Mon Sep 17 00:00:00 2001
From: Brooklyn Nicholson <brooklyn.bb.nicholson@gmail.com>
Date: Wed, 29 Jul 2026 02:05:43 -0500
Subject: [PATCH] fix(desktop): track kanban lane phase in state, not a
 mirrored ref
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main landed a lint rule banning refs mirrored from reactive values in an
effect — they lag a render and cause stale reads. The lane-collapse
override tracker did exactly that with a counts ref.

Hold the empty/non-empty signature in state instead. React bails out
when it's unchanged, so a poll where no lane's emptiness moved costs no
extra render, and the comparison always sees the current value.
---
 .../lib/keybinds/contributed-actions.test.ts  |  2 +-
 apps/desktop/src/plugins/kanban/board.tsx     | 29 ++++++++++++-------
 2 files changed, 20 insertions(+), 11 deletions(-)

diff --git a/apps/desktop/src/lib/keybinds/contributed-actions.test.ts b/apps/desktop/src/lib/keybinds/contributed-actions.test.ts
index e5eb72b149d..0b82242789f 100644
--- a/apps/desktop/src/lib/keybinds/contributed-actions.test.ts
+++ b/apps/desktop/src/lib/keybinds/contributed-actions.test.ts
@@ -1,7 +1,7 @@
 import { describe, expect, it } from 'vitest'
 
-import { registry } from '@/contrib/registry'
 import { createPluginContext } from '@/contrib/plugin'
+import { registry } from '@/contrib/registry'
 import { allKeybindActions, contributedKeybindHandler, KEYBINDS_AREA } from '@/lib/keybinds/actions'
 import { bindingsFor } from '@/store/keybinds'
 
diff --git a/apps/desktop/src/plugins/kanban/board.tsx b/apps/desktop/src/plugins/kanban/board.tsx
index a68f3fafdc1..fa53a26f969 100644
--- a/apps/desktop/src/plugins/kanban/board.tsx
+++ b/apps/desktop/src/plugins/kanban/board.tsx
@@ -1244,28 +1244,37 @@ export function KanbanBoardPage() {
   // override is dropped and auto takes over — so a drained lane collapses even
   // if it was manually expanded ages ago, while expanding an empty lane still
   // sticks for as long as it stays empty.
-  const laneCounts = useRef<null | Record<string, number>>(null)
+  //
+  // The phase is a string signature held in state, not a ref: React bails out
+  // when it's unchanged, so the common case (a poll where no lane's emptiness
+  // moved) costs no extra render, and nothing lags a render behind the value
+  // it mirrors.
+  const lanePhase = filtered
+    ? filtered.columns.map(col => `${col.name}:${col.tasks.length === 0 ? 'empty' : 'full'}`).join('|')
+    : null
+
+  const [prevLanePhase, setPrevLanePhase] = useState<null | string>(null)
 
   useEffect(() => {
-    if (!filtered) {
+    if (lanePhase === null || lanePhase === prevLanePhase) {
       return
     }
 
-    const counts = Object.fromEntries(filtered.columns.map(col => [col.name, col.tasks.length]))
-    const prev = laneCounts.current
-    laneCounts.current = counts
+    setPrevLanePhase(lanePhase)
 
-    if (!prev) {
+    if (prevLanePhase === null) {
       return
     }
 
+    const before = new Map(prevLanePhase.split('|').map(entry => entry.split(':') as [string, string]))
     const overrides = { ...$collapsedLanes.get() }
     let changed = false
 
-    for (const [name, count] of Object.entries(counts)) {
-      const before = prev[name]
+    for (const entry of lanePhase.split('|')) {
+      const [name, phase] = entry.split(':')
+      const was = before.get(name)
 
-      if (before !== undefined && (before === 0) !== (count === 0) && name in overrides) {
+      if (was !== undefined && was !== phase && name in overrides) {
         delete overrides[name]
         changed = true
       }
@@ -1274,7 +1283,7 @@ export function KanbanBoardPage() {
     if (changed) {
       $collapsedLanes.set(overrides)
     }
-  }, [filtered])
+  }, [lanePhase, prevLanePhase])
 
   const toggleLane = (name: string, auto: boolean) => {
     const overrides = { ...laneOverrides }