feat(vite-node): vite hmr support

packages/vite-node/src/cli.ts

@@ -1,11 +1,12 @@
 import cac from 'cac'
-import { cyan, dim, red } from 'kolorist'
+import { red } from 'kolorist'
 import { createServer } from 'vite'
 import { version } from '../package.json'
 import { ViteNodeServer } from './server'
 import { ViteNodeRunner } from './client'
 import type { ViteNodeServerOptions } from './types'
 import { toArray } from './utils'
+import { createHotContext, handleMessage, viteNodeHmrPlugin } from './hmr'
 
 const cli = cac('vite-node')
 
@@ -49,6 +50,9 @@ async function run(files: string[], options: CliOptions = {}) {
     logLevel: 'error',
     configFile: options.config,
     root: options.root,
+    plugins: [
+      viteNodeHmrPlugin(),
+    ],
   })
   await server.pluginContainer.buildStart({})
 
@@ -63,6 +67,9 @@ async function run(files: string[], options: CliOptions = {}) {
     resolveId(id, importer) {
       return node.resolveId(id, importer)
     },
+    createHotContext(runner, url) {
+      return createHotContext(runner, server.emitter, files, url)
+    },
   })
 
   // provide the vite define variable in this context
@@ -74,18 +81,8 @@ async function run(files: string[], options: CliOptions = {}) {
   if (!options.watch)
     await server.close()
 
-  server.watcher.on('change', async (path) => {
-    console.log(`${cyan('[vite-node]')} File change detected. ${dim(path)}`)
-
-    // invalidate module cache but not node_modules
-    Array.from(runner.moduleCache.keys())
-      .forEach((i) => {
-        if (!i.includes('node_modules'))
-          runner.moduleCache.delete(i)
-      })
-
-    for (const file of files)
-      await runner.executeFile(file)
+  server.emitter.on('message', (payload) => {
+    handleMessage(runner, server.emitter, files, payload)
   })
 }
 

packages/vite-node/src/client.ts

@@ -187,7 +187,10 @@ export class ViteNodeRunner {
       __vite_ssr_dynamic_import__: request,
       __vite_ssr_exports__: exports,
       __vite_ssr_exportAll__: (obj: any) => exportAll(exports, obj),
-      __vite_ssr_import_meta__: { url },
+      __vite_ssr_import_meta__: {
+        url,
+        hot: this.options.createHotContext?.(this, `/@fs/${fsPath}`),
+      },
 
       __vitest_resolve_id__: resolveId,
 

packages/vite-node/src/hmr/emitter.ts

@@ -0,0 +1,42 @@
+import { EventEmitter } from 'events'
+import type { HMRPayload, Plugin } from 'vite'
+
+export type EventType = string | symbol
+export type Handler<T = unknown> = (event: T) => void
+export interface Emitter<Events extends Record<EventType, unknown>> {
+  on<Key extends keyof Events>(type: Key, handler: Handler<Events[Key]>): void
+  off<Key extends keyof Events>(type: Key, handler?: Handler<Events[Key]>): void
+  emit<Key extends keyof Events>(type: Key, event: Events[Key]): void
+  emit<Key extends keyof Events>(type: undefined extends Events[Key] ? Key : never): void
+}
+
+export type HMREmitter = Emitter<{
+  'message': HMRPayload
+}> & EventEmitter
+
+declare module 'vite' {
+  interface ViteDevServer {
+    emitter: HMREmitter
+  }
+}
+
+export function createHmrEmitter(): HMREmitter {
+  const emitter = new EventEmitter()
+  return emitter
+}
+
+export function viteNodeHmrPlugin(): Plugin {
+  const emitter = createHmrEmitter()
+  return {
+    name: 'vite-node:hmr',
+
+    configureServer(server) {
+      const _send = server.ws.send
+      server.emitter = emitter
+      server.ws.send = function (payload: HMRPayload) {
+        _send(payload)
+        emitter.emit('message', payload)
+      }
+    },
+  }
+}