fix(kit): guard reinstall and stale plugin replay

packages/kit/src/kit.ts

@@ -112,6 +112,12 @@ export function createDevtoolsKit(options: DevtoolsKitOptions): DevtoolsKit {
     plugins,
     install() {
       if (installed) return
+      // dispose() clears the runtime handlers and RPC; reinstalling would give a hook
+      // feeding a runtime that answers nothing. Create a new kit instead.
+      if (disposed) {
+        console.warn('[vue-devtools] install() called on a disposed kit; create a new kit instead')
+        return
+      }
 
       const owners = ownerTarget[DEVTOOLS_KIT_OWNERS] ?? new Map<string, DevtoolsKit>()
       const previousOwner = owners.get(clientName)
@@ -120,7 +126,6 @@ export function createDevtoolsKit(options: DevtoolsKitOptions): DevtoolsKit {
       ownerTarget[DEVTOOLS_KIT_OWNERS] = owners
 
       installed = true
-      disposed = false
 
       if (enabled && options.hook?.install !== false) {
         installedHook = installDevtoolsHook({

packages/kit/src/plugin/registry.ts

@@ -108,6 +108,13 @@ export function createPluginController(runtime: DevtoolsRuntime): PluginControll
   }
   state.listeners.add(listener)
   state.bufferedPlugins.forEach(listener)
+  // An unmounted app never comes back, so a later kit must not replay its setups.
+  const disposeUnmount = runtime.subscribe('app:unmount', (event) => {
+    if (event.type !== 'app:unmount' || event.app == null) return
+    state.bufferedPlugins = state.bufferedPlugins.filter(
+      ([descriptor]) => descriptor.app !== event.app,
+    )
+  })
 
   async function callAdapterHook(adapter: PluginApiAdapter, key: string, payload: unknown) {
     if (!acceptsApp(adapter.descriptor, payload)) return
@@ -131,6 +138,7 @@ export function createPluginController(runtime: DevtoolsRuntime): PluginControll
     },
     dispose() {
       state.listeners.delete(listener)
+      disposeUnmount()
       plugins.clear()
       adapters.clear()
     },

tests/unit/plugin/kit-lifecycle.test.ts

@@ -0,0 +1,70 @@
+import { afterEach, expect, it, vi } from 'vitest'
+import type { DevtoolsKit } from '../../../packages/kit/src/kit'
+import { createDevtoolsKit } from '../../../packages/kit/src/kit'
+import { setupDevToolsPlugin } from '../../../packages/kit/src/plugin'
+import { createComponentTreeFixture } from '../../fixtures'
+
+const kits: DevtoolsKit[] = []
+
+afterEach(async () => {
+  for (const kit of kits.splice(0)) await kit.dispose()
+})
+
+function createKit(): DevtoolsKit {
+  const kit = createDevtoolsKit({ target: { name: 'Lifecycle Test' }, hook: { install: false } })
+  kit.install()
+  kits.push(kit)
+  return kit
+}
+
+it('does not reinstall a disposed kit', async () => {
+  const warn = vi.spyOn(console, 'warn').mockImplementation(() => {})
+  const kit = createKit()
+  await kit.dispose()
+
+  kit.install()
+
+  expect(warn).toHaveBeenCalledOnce()
+  expect(kit.plugins.adapters.size).toBe(0)
+})
+
+it('does not replay plugin setups for an unmounted app into a later kit', async () => {
+  const first = createKit()
+  const fixture = createComponentTreeFixture(1)
+  first.runtime.dispatch({
+    type: 'app:init',
+    app: fixture.app,
+    time: 1,
+    version: '3.5.0',
+    vueTypes: {},
+  })
+  const setup = vi.fn()
+  setupDevToolsPlugin({ id: 'plugin:replay', app: fixture.app }, setup)
+  await vi.waitFor(() => expect(setup).toHaveBeenCalledOnce())
+
+  first.runtime.dispatch({ type: 'app:unmount', app: fixture.app, time: 2 })
+  await first.dispose()
+  createKit()
+  await new Promise((resolve) => setTimeout(resolve, 0))
+
+  expect(setup).toHaveBeenCalledOnce()
+})
+
+it('still replays plugin setups for a mounted app into a later kit', async () => {
+  const first = createKit()
+  const fixture = createComponentTreeFixture(1)
+  first.runtime.dispatch({
+    type: 'app:init',
+    app: fixture.app,
+    time: 1,
+    version: '3.5.0',
+    vueTypes: {},
+  })
+  const setup = vi.fn()
+  setupDevToolsPlugin({ id: 'plugin:kept', app: fixture.app }, setup)
+  await vi.waitFor(() => expect(setup).toHaveBeenCalledOnce())
+
+  await first.dispose()
+  createKit()
+  await vi.waitFor(() => expect(setup).toHaveBeenCalledTimes(2))
+})