feat(kit)!: basic shared state

alias.ts

@@ -6,9 +6,9 @@ const root = fileURLToPath(new URL('.', import.meta.url))
 const r = (path: string) => fileURLToPath(new URL(`./packages/${path}`, import.meta.url))
 
 export const alias = {
-  '@vitejs/devtools-rpc': r('rpc/src'),
   '@vitejs/devtools-rpc/presets/ws/server': r('rpc/src/presets/ws/server.ts'),
   '@vitejs/devtools-rpc/presets/ws/client': r('rpc/src/presets/ws/client.ts'),
+  '@vitejs/devtools-rpc': r('rpc/src'),
   '@vitejs/devtools-kit/client': r('kit/src/client/index.ts'),
   '@vitejs/devtools-kit/utils/events': r('kit/src/utils/events.ts'),
   '@vitejs/devtools-kit/utils/nanoid': r('kit/src/utils/nanoid.ts'),

docs/kit/index.md

@@ -19,6 +19,8 @@ DevTools Kit offers a complete toolkit for building DevTools integrations:
 
 - **🔌 [Built-in RPC Layer](#remote-procedure-calls-rpc)**: Type-safe bidirectional communication between your Node.js server and browser clients, eliminating the need to set up WebSocket connections or message passing manually
 
+- **🔗 [Shared State](#shared-state)**: Share data between server and client with automatic synchronization
+
 - **🌐 Isomorphic Views Hosting**: Write your UI once and deploy it anywhere—as embedded floating panels, browser extension panels, standalone webpages, or even deployable SPAs for sharing build snapshots (work in progress).
 
 ## Why DevTools Kit?
@@ -418,6 +420,89 @@ rpc.client.register({
 })
 ```
 
+### Shared State
+
+The DevTools Kit provides a built-in shared state system that enables you to share data between the server and client with automatic synchronization.
+
+On the server side, you can get the shared state using `ctx.rpc.sharedState.get(name, options)`:
+
+```ts {6-10}
+export default function myPlugin(): Plugin {
+  return {
+    name: 'my-plugin',
+    devtools: {
+      async setup(ctx) {
+        // Get the shared state
+        const state = await ctx.rpc.sharedState.get('my-plugin:state', {
+          initialValue: {
+            count: 0,
+            name: 'John Doe',
+          },
+        })
+
+        // Use .value() to get the current state
+        console.log(state.value()) // { count: 0, name: 'John Doe' }
+
+        setTimeout(() => {
+          // Mutate the shared state, changes will be automatically synchronized to all the connected clients
+          state.mutate((state) => {
+            state.count += 1
+          })
+        }, 1000)
+      },
+    },
+  }
+}
+```
+
+<details>
+<summary>Type-safe shared state</summary>
+
+The shared state is type-safe, you can get the state with the type of the initial value. To do so, you need to extend the `DevToolsRpcSharedStates` interface in your plugin's type definitions.
+
+```ts [src/types.ts]
+import '@vitejs/devtools-kit'
+
+declare module '@vitejs/devtools-kit' {
+  interface DevToolsRpcSharedStates {
+    'my-plugin:state': { count: number, name: string }
+  }
+}
+```
+
+</details>
+
+On the client side, you can get the shared state using `client.rpc.sharedState.get(name)`:
+
+```ts {6-10}
+import { getDevToolsRpcClient } from '@vitejs/devtools-kit/client'
+
+const client = await getDevToolsRpcClient()
+
+const state = await client.rpc.sharedState.get('my-plugin:state')
+
+console.log(state.value()) // { count: 0, name: 'John Doe' }
+
+// Use .on('updated') to subscribe to changes
+state.on('updated', (newState) => {
+  console.log(newState) // { count: 1, name: 'John Doe' }
+})
+```
+
+For example, if you use Vue, you can wrap it into a reactive ref:
+
+```ts {6-10}
+import { shallowRef } from 'vue'
+
+const sharedState = await client.rpc.sharedState.get('my-plugin:state')
+const state = shallowRef(sharedState.value())
+sharedState.on('updated', (newState) => {
+  state.value = newState
+})
+
+// Now the `state` ref will be updated automatically when the shared state changes
+```
+
 ## References
 
 The docs might not cover all the details, please help us to improve it by submitting PRs. And in the meantime, you can refer to the following existing DevTools integrations for reference (but note they might not always be up to date with the latest API changes):

packages/core/package.json

@@ -79,8 +79,10 @@
     "tsdown": "catalog:build",
     "typescript": "catalog:devtools",
     "unplugin-vue": "catalog:build",
+    "unplugin-vue-router": "catalog:playground",
     "vite": "catalog:build",
     "vue": "catalog:frontend",
+    "vue-router": "catalog:playground",
     "vue-tsc": "catalog:devtools"
   }
 }

packages/core/playground/src/App.vue

@@ -1,30 +1,8 @@
-<script setup lang="ts">
-import HelloWorld from './components/HelloWorld.vue'
-</script>
-
 <template>
-  <div>
-    <a href="https://vite.dev" target="_blank">
-      <img src="/vite.svg" class="logo" alt="Vite logo">
-    </a>
-    <a href="https://vuejs.org/" target="_blank">
-      <img src="./assets/vue.svg" class="logo vue" alt="Vue logo">
-    </a>
-  </div>
-  <HelloWorld msg="Vite + Vue" />
+  <Suspense>
+    <RouterView />
+    <template #fallback>
+      <div>Loading...</div>
+    </template>
+  </Suspense>
 </template>
-
-<style scoped>
-.logo {
-  height: 6em;
-  padding: 1.5em;
-  will-change: filter;
-  transition: filter 300ms;
-}
-.logo:hover {
-  filter: drop-shadow(0 0 2em #646cffaa);
-}
-.logo.vue:hover {
-  filter: drop-shadow(0 0 2em #42b883aa);
-}
-</style>

packages/core/playground/src/main.ts

@@ -1,5 +1,15 @@
 import { createApp } from 'vue'
+import { createRouter, createWebHistory } from 'vue-router'
+import { routes } from 'vue-router/auto-routes'
+
 import App from './App.vue'
 import './style.css'
 
-createApp(App).mount('#app')
+const router = createRouter({
+  history: createWebHistory(),
+  routes,
+})
+
+createApp(App)
+  .use(router)
+  .mount('#app')

packages/core/playground/src/pages/devtools.vue

@@ -0,0 +1,42 @@
+<script setup lang="ts">
+import { getDevToolsRpcClient } from '@vitejs/devtools-kit/client'
+import { onMounted, shallowRef } from 'vue'
+
+const stateRef = shallowRef<any>(undefined)
+const isTrustedRef = shallowRef<boolean | null>(null)
+
+let increment = () => {}
+
+onMounted(async () => {
+  const client = await getDevToolsRpcClient()
+
+  isTrustedRef.value = client.isTrusted
+  client.events.on('rpc:is-trusted:updated', (isTrusted) => {
+    isTrustedRef.value = isTrusted
+  })
+
+  const state = await client.sharedState.get('counter')
+
+  increment = () => {
+    state.mutate((state) => {
+      state.count++
+    })
+  }
+
+  stateRef.value = state.value()
+  state.on('updated', (newState) => {
+    stateRef.value = newState
+  })
+})
+</script>
+
+<template>
+  <div>
+    <h1>DevTools </h1>
+    <div>{{ isTrustedRef }}</div>
+    <pre>{{ stateRef }}</pre>
+    <button @click="increment">
+      Increment
+    </button>
+  </div>
+</template>

packages/core/playground/src/pages/index.vue

@@ -0,0 +1,30 @@
+<script setup lang="ts">
+import HelloWorld from '../components/HelloWorld.vue'
+</script>
+
+<template>
+  <div>
+    <a href="https://vite.dev" target="_blank">
+      <img src="/vite.svg" class="logo" alt="Vite logo">
+    </a>
+    <a href="https://vuejs.org/" target="_blank">
+      <img src="../assets/vue.svg" class="logo vue" alt="Vue logo">
+    </a>
+  </div>
+  <HelloWorld msg="Vite + Vue" />
+</template>
+
+<style scoped>
+.logo {
+  height: 6em;
+  padding: 1.5em;
+  will-change: filter;
+  transition: filter 300ms;
+}
+.logo:hover {
+  filter: drop-shadow(0 0 2em #646cffaa);
+}
+.logo.vue:hover {
+  filter: drop-shadow(0 0 2em #42b883aa);
+}
+</style>

packages/core/playground/typed-router.d.ts

@@ -23,6 +23,20 @@ declare module 'vue-router/auto-routes' {
    * Route name map generated by unplugin-vue-router
    */
   export interface RouteNamedMap {
+    '/': RouteRecordInfo<
+      '/',
+      '/',
+      Record<never, never>,
+      Record<never, never>,
+      | never
+    >,
+    '/devtools': RouteRecordInfo<
+      '/devtools',
+      '/devtools',
+      Record<never, never>,
+      Record<never, never>,
+      | never
+    >,
   }
 
   /**
@@ -36,6 +50,18 @@ declare module 'vue-router/auto-routes' {
    * @internal
    */
   export interface _RouteFileInfoMap {
+    'src/pages/index.vue': {
+      routes:
+        | '/'
+      views:
+        | never
+    }
+    'src/pages/devtools.vue': {
+      routes:
+        | '/devtools'
+      views:
+        | never
+    }
   }
 
   /**

packages/core/playground/vite.config.ts

@@ -1,21 +1,33 @@
 import process from 'node:process'
 import Vue from '@vitejs/plugin-vue'
 import UnoCSS from 'unocss/vite'
+import VueRouter from 'unplugin-vue-router/vite'
 import { defineConfig } from 'vite'
 import Tracer from 'vite-plugin-vue-tracer'
+import { alias } from '../../../alias'
 // eslint-disable-next-line ts/ban-ts-comment
 // @ts-ignore ignore the type error
 import { DevToolsViteUI } from '../../vite/src/node'
 import { DevTools } from '../src'
 import { buildCSS } from '../src/client/webcomponents/scripts/build-css'
 
+declare module '@vitejs/devtools-kit' {
+  interface DevToolsRpcSharedStates {
+    counter: { count: number }
+  }
+}
+
 // https://vite.dev/config/
 export default defineConfig({
   define: {
     'import.meta.env.VITE_DEVTOOLS_LOCAL_DEV': JSON.stringify(process.env.VITE_DEVTOOLS_LOCAL_DEV),
   },
   base: './',
+  resolve: {
+    alias,
+  },
   plugins: [
+    VueRouter(),
     Vue(),
     {
       name: 'build-css',
@@ -38,7 +50,7 @@ export default defineConfig({
     {
       name: 'local',
       devtools: {
-        setup(ctx) {
+        async setup(ctx) {
           ctx.docks.register({
             title: 'Local',
             icon: 'logos:vue',
@@ -94,6 +106,14 @@ export default defineConfig({
             action: ctx.utils.createSimpleClientScript(() => {}),
           })
 
+          ctx.docks.register({
+            id: 'devtools-tab',
+            type: 'iframe',
+            url: '/devtools/',
+            title: 'DevTools',
+            icon: 'ph:gear-duotone',
+          })
+
           ctx.docks.register({
             id: 'launcher',
             type: 'launcher',
@@ -123,10 +143,16 @@ export default defineConfig({
             },
           })
 
-          let count = 1
+          const counterState = await ctx.rpc.sharedState.get('counter', {
+            initialValue: { count: 1 },
+          })
+
           // eslint-disable-next-line unimport/auto-insert
           setInterval(() => {
-            count = (count + 1) % 5
+            counterState.mutate((current) => {
+              current.count = (current.count + 1) % 5
+            })
+            const count = counterState.value().count
             ctx.docks.update({
               id: 'counter',
               type: 'action',

packages/core/src/node/context.ts

@@ -46,15 +46,27 @@ export async function createDevToolsContext(
 
   // Register hosts side effects
   docksHost.events.on('dock:entry:updated', debounce(() => {
-    rpcHost.broadcast('vite:internal:docks:updated')
+    rpcHost.broadcast({
+      method: 'vite:internal:docks:updated',
+      args: [],
+    })
   }, 10))
   terminalsHost.events.on('terminal:session:updated', debounce(() => {
-    rpcHost.broadcast('vite:internal:terminals:updated')
+    rpcHost.broadcast({
+      method: 'vite:internal:terminals:updated',
+      args: [],
+    })
     // New terminals might affect the visibility of the terminals dock entry, we trigger it here as well
-    rpcHost.broadcast('vite:internal:docks:updated')
+    rpcHost.broadcast({
+      method: 'vite:internal:docks:updated',
+      args: [],
+    })
   }, 10))
   terminalsHost.events.on('terminal:session:stream-chunk', (data) => {
-    rpcHost.broadcast('vite:internal:terminals:stream-chunk', data)
+    rpcHost.broadcast({
+      method: 'vite:internal:terminals:stream-chunk',
+      args: [data],
+    })
   })
 
   // Register plugins