fix(reconnect): release obsolete app state held by handle-gap watchers (#24815)

Co-authored-by: OrcaWin <293788423+OrcaWin@users.noreply.github.com>

src/renderer/src/lib/host-mirror-handle-gap-snapshot-lifetime.test.ts

@@ -0,0 +1,120 @@
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
+import { useAppStore, type AppState } from '@/store'
+import { makeTab } from '@/store/slices/store-test-helpers'
+import {
+  clearRuntimeEnvironmentConnectionGenerationsForTests,
+  setRuntimeEnvironmentConnectionGenerationForTests
+} from '@/store/slices/runtime-status'
+import {
+  HOST_MIRROR_HANDLE_GAP_DEADLINE_MS,
+  countHostMirrorHandleGapVerdictsForTests,
+  countParkedHostMirrorHandleGapPanesForTests,
+  hasHostMirrorHandleWaitExpired,
+  parkUntilHostMirrorHandleLands,
+  resetHostMirrorHandleGapWaitsForTests
+} from './host-mirror-handle-gap-wait'
+
+const ENVIRONMENT_ID = 'env-snapshot-lifetime'
+const WORKTREE_ID = 'repo-1::/workspace/snapshot-lifetime'
+const TAB_ID = 'tab-snapshot-lifetime'
+const LEAF_ID = '11111111-1111-4111-8111-111111111111'
+const PTY_ID = `remote:${ENVIRONMENT_ID}@@term_snapshot`
+const FILE_ID = 'discarded-document'
+const initialAppStoreState = useAppStore.getState()
+
+async function collectRetiredSnapshots(): Promise<void> {
+  if (typeof globalThis.gc !== 'function') {
+    throw new Error('Run with the repository Vitest --expose-gc config')
+  }
+  for (let round = 0; round < 3; round += 1) {
+    await new Promise<void>((resolve) => setImmediate(resolve))
+    globalThis.gc()
+  }
+}
+
+function parkAndRemoveDraft(source: 'initial' | 'terminal-write', replay: () => void) {
+  useAppStore.getState().setEditorDraft(FILE_ID, 'discarded document text\n')
+  parkUntilHostMirrorHandleLands(ENVIRONMENT_ID, WORKTREE_ID, TAB_ID, replay)
+  if (source === 'terminal-write') {
+    useAppStore.setState({
+      ptyIdsByTabId: { ...useAppStore.getState().ptyIdsByTabId, 'another-tab': ['another-pty'] }
+    })
+  }
+  const state = useAppStore.getState()
+  const retired = {
+    snapshot: new WeakRef<AppState>(state),
+    drafts: new WeakRef(state.editorDrafts)
+  }
+  state.clearEditorDraft(FILE_ID)
+  return retired
+}
+
+beforeEach(() => {
+  vi.useFakeTimers({ toFake: ['setTimeout', 'clearTimeout', 'Date'] })
+  resetHostMirrorHandleGapWaitsForTests()
+  clearRuntimeEnvironmentConnectionGenerationsForTests()
+  useAppStore.setState(initialAppStoreState, true)
+  setRuntimeEnvironmentConnectionGenerationForTests(ENVIRONMENT_ID, 1)
+  useAppStore.setState({
+    ptyIdsByTabId: {},
+    tabsByWorktree: {
+      [WORKTREE_ID]: [makeTab({ id: TAB_ID, worktreeId: WORKTREE_ID })]
+    },
+    terminalLayoutsByTabId: {
+      [TAB_ID]: {
+        root: { type: 'leaf', leafId: LEAF_ID },
+        activeLeafId: LEAF_ID,
+        expandedLeafId: null,
+        ptyIdsByLeafId: { [LEAF_ID]: PTY_ID }
+      }
+    }
+  })
+})
+
+afterEach(() => {
+  resetHostMirrorHandleGapWaitsForTests()
+  clearRuntimeEnvironmentConnectionGenerationsForTests()
+  useAppStore.setState(initialAppStoreState, true)
+  vi.restoreAllMocks()
+  vi.useRealTimers()
+})
+
+describe('host-mirror handle-gap snapshot lifetime', () => {
+  it.each([
+    { source: 'initial', lifetime: 'pending' },
+    { source: 'terminal-write', lifetime: 'pending' },
+    { source: 'initial', lifetime: 'verdict' },
+    { source: 'terminal-write', lifetime: 'verdict' }
+  ] as const)('releases the $source snapshot during $lifetime observation', async (scenario) => {
+    const replay = vi.fn<() => void>()
+    const retired = parkAndRemoveDraft(scenario.source, replay)
+    const ptyIds = useAppStore.getState().ptyIdsByTabId
+    const tabs = useAppStore.getState().tabsByWorktree
+    if (scenario.lifetime === 'verdict') {
+      vi.advanceTimersByTime(HOST_MIRROR_HANDLE_GAP_DEADLINE_MS)
+      expect(countParkedHostMirrorHandleGapPanesForTests()).toBe(0)
+      expect(countHostMirrorHandleGapVerdictsForTests()).toBe(1)
+      expect(hasHostMirrorHandleWaitExpired(ENVIRONMENT_ID, TAB_ID)).toBe(true)
+      expect(replay).toHaveBeenCalledTimes(1)
+    } else {
+      expect(countParkedHostMirrorHandleGapPanesForTests()).toBe(1)
+      expect(countHostMirrorHandleGapVerdictsForTests()).toBe(0)
+      expect(replay).not.toHaveBeenCalled()
+    }
+
+    expect(useAppStore.getState().editorDrafts[FILE_ID]).toBeUndefined()
+    expect(useAppStore.getState().ptyIdsByTabId).toBe(ptyIds)
+    expect(useAppStore.getState().tabsByWorktree).toBe(tabs)
+    replay.mockClear()
+    await collectRetiredSnapshots()
+    expect(retired.snapshot.deref()).toBeUndefined()
+    expect(retired.drafts.deref()).toBeUndefined()
+
+    useAppStore.setState({ ptyIdsByTabId: { ...ptyIds, [TAB_ID]: [PTY_ID] } })
+    expect(countParkedHostMirrorHandleGapPanesForTests()).toBe(0)
+    expect(countHostMirrorHandleGapVerdictsForTests()).toBe(0)
+    expect(hasHostMirrorHandleWaitExpired(ENVIRONMENT_ID, TAB_ID)).toBe(false)
+    expect(replay).toHaveBeenCalledTimes(scenario.lifetime === 'pending' ? 1 : 0)
+    expect(vi.getTimerCount()).toBe(0)
+  })
+})

src/renderer/src/lib/host-mirror-handle-gap-wait.ts

@@ -357,17 +357,19 @@ function startStoreSubscription(): void {
   if (unsubscribeStore) {
     return
   }
-  let previous: HandleGapStoreState = useAppStore.getState()
+  let { ptyIdsByTabId: previousPtyIdsByTabId, tabsByWorktree: previousTabsByWorktree } =
+    useAppStore.getState()
   unsubscribeStore = useAppStore.subscribe((state) => {
     // Why: only these two slices can release a waiter; title, status, and
     // usage ticks must not rescan every parked pane.
     if (
-      state.ptyIdsByTabId === previous.ptyIdsByTabId &&
-      state.tabsByWorktree === previous.tabsByWorktree
+      state.ptyIdsByTabId === previousPtyIdsByTabId &&
+      state.tabsByWorktree === previousTabsByWorktree
     ) {
       return
     }
-    previous = state
+    previousPtyIdsByTabId = state.ptyIdsByTabId
+    previousTabsByWorktree = state.tabsByWorktree
     retireVerdictsWithLandedHandles(state)
     releaseDueWaiters(state)
     stopStoreSubscriptionIfIdle()