fix(app): improve tab handling (#30669)

packages/app/src/context/layout-helpers.ts

@@ -0,0 +1,38 @@
+import type { Accessor } from "solid-js"
+
+export function ensureSessionKey(key: string, touch: (key: string) => void, seed: (key: string) => void) {
+  touch(key)
+  seed(key)
+  return key
+}
+
+export function createSessionKeyReader(sessionKey: string | Accessor<string>, ensure: (key: string) => void) {
+  const key = typeof sessionKey === "function" ? sessionKey : () => sessionKey
+  return () => {
+    const value = key()
+    ensure(value)
+    return value
+  }
+}
+
+export function pruneSessionKeys(input: {
+  keep?: string
+  max: number
+  used: Map<string, number>
+  view: string[]
+  tabs: string[]
+}) {
+  if (!input.keep) return []
+
+  const keys = new Set<string>([...input.view, ...input.tabs])
+  if (keys.size <= input.max) return []
+
+  const score = (key: string) => {
+    if (key === input.keep) return Number.MAX_SAFE_INTEGER
+    return input.used.get(key) ?? 0
+  }
+
+  return Array.from(keys)
+    .sort((a, b) => score(b) - score(a))
+    .slice(input.max)
+}