feat: introduce RunnableDevEnvironment

packages/vite/src/node/config.ts

@@ -39,7 +39,7 @@ import { resolveBuildEnvironmentOptions, resolveBuilderOptions } from './build'
 import type { ResolvedServerOptions, ServerOptions } from './server'
 import { resolveServerOptions } from './server'
 import { DevEnvironment } from './server/environment'
-import { createNodeDevEnvironment } from './server/environments/nodeEnvironment'
+import { createRunnableDevEnvironment } from './server/environments/runnableEnvironment'
 import { createServerHotChannel } from './server/hmr'
 import type { WebSocketServer } from './server/ws'
 import type { PreviewOptions, ResolvedPreviewOptions } from './preview'
@@ -213,7 +213,7 @@ function defaultCreateSsrDevEnvironment(
   name: string,
   config: ResolvedConfig,
 ): DevEnvironment {
-  return createNodeDevEnvironment(name, config, {
+  return createRunnableDevEnvironment(name, config, {
     hot: createServerHotChannel(),
   })
 }

packages/vite/src/node/index.ts

@@ -20,7 +20,11 @@ export { transformWithEsbuild } from './plugins/esbuild'
 export { buildErrorMessage } from './server/middlewares/error'
 
 export { RemoteEnvironmentTransport } from './server/environmentTransport'
-export { createNodeDevEnvironment } from './server/environments/nodeEnvironment'
+export {
+  createRunnableDevEnvironment,
+  isRunnableDevEnvironment,
+  type RunnableDevEnvironment,
+} from './server/environments/runnableEnvironment'
 export {
   DevEnvironment,
   type DevEnvironmentContext,

packages/vite/src/node/server/environment.ts

@@ -35,7 +35,7 @@ import type { RemoteEnvironmentTransport } from './environmentTransport'
 export interface DevEnvironmentContext {
   hot: false | HotChannel
   options?: EnvironmentOptions
-  runner?: FetchModuleOptions & {
+  runnerOptions?: FetchModuleOptions & {
     transport?: RemoteEnvironmentTransport
   }
   depsOptimizer?: DepsOptimizer
@@ -123,8 +123,8 @@ export class DevEnvironment extends BaseEnvironment {
       this._onCrawlEndCallbacks.forEach((cb) => cb())
     })
 
-    this._ssrRunnerOptions = context.runner ?? {}
-    context.runner?.transport?.register(this)
+    this._ssrRunnerOptions = context.runnerOptions ?? {}
+    context.runnerOptions?.transport?.register(this)
 
     this.hot.on('vite:invalidate', async ({ path, message }) => {
       invalidateModule(this, {

packages/vite/src/node/server/environments/runnableEnvironment.ts

@@ -0,0 +1,61 @@
+import type { ModuleRunner } from 'vite/module-runner'
+import type { ResolvedConfig } from '../../config'
+import type { DevEnvironmentContext } from '../environment'
+import { DevEnvironment } from '../environment'
+import { asyncFunctionDeclarationPaddingLineCount } from '../../../shared/utils'
+import { createServerModuleRunner } from '../../ssr/runtime/serverModuleRunner'
+
+export function createRunnableDevEnvironment(
+  name: string,
+  config: ResolvedConfig,
+  context: DevEnvironmentContext,
+): DevEnvironment {
+  if (context.hot == null) {
+    throw new Error(
+      '`hot` is a required option. Either explicitly opt out of HMR by setting `hot: false` or provide a hot channel.',
+    )
+  }
+
+  return new RunnableDevEnvironment(name, config, {
+    ...context,
+    runnerOptions: {
+      processSourceMap(map) {
+        // this assumes that "new AsyncFunction" is used to create the module
+        return Object.assign({}, map, {
+          mappings:
+            ';'.repeat(asyncFunctionDeclarationPaddingLineCount) + map.mappings,
+        })
+      },
+      ...context.runnerOptions,
+    },
+  })
+}
+
+export interface RunnableDevEnvironmentContext extends DevEnvironmentContext {
+  runner?: ModuleRunner
+}
+
+export function isRunnableDevEnvironment(
+  environment: DevEnvironment,
+): environment is RunnableDevEnvironment {
+  return environment instanceof RunnableDevEnvironment
+}
+
+class RunnableDevEnvironment extends DevEnvironment {
+  public readonly runner: ModuleRunner
+
+  constructor(
+    name: string,
+    config: ResolvedConfig,
+    context: RunnableDevEnvironmentContext,
+  ) {
+    super(name, config, context)
+    this.runner = context.runner || createServerModuleRunner(this)
+  }
+
+  import<T = any>(url: string): Promise<T> {
+    return this.runner.import<T>(url)
+  }
+}
+
+export type { RunnableDevEnvironment }