fix: optimize deps on dev SSR, builtin imports in node (#8854)

Author: patak-dev

packages/vite/src/node/optimizer/esbuildDepPlugin.ts

@@ -5,6 +5,7 @@ import { KNOWN_ASSET_TYPES } from '../constants'
 import type { ResolvedConfig } from '..'
 import {
   flattenId,
+  isBuiltin,
   isExternalUrl,
   isRunningWithYarnPnp,
   moduleListContains,
@@ -42,7 +43,8 @@ const externalTypes = [
 export function esbuildDepPlugin(
   qualified: Record<string, string>,
   exportsData: Record<string, ExportsData>,
-  config: ResolvedConfig
+  config: ResolvedConfig,
+  ssr: boolean
 ): Plugin {
   // remove optimizable extensions from `externalTypes` list
   const allExternalTypes = config.optimizeDeps.extensions
@@ -77,7 +79,7 @@ export function esbuildDepPlugin(
       _importer = importer in qualified ? qualified[importer] : importer
     }
     const resolver = kind.startsWith('require') ? _resolveRequire : _resolve
-    return resolver(id, _importer, undefined)
+    return resolver(id, _importer, undefined, ssr)
   }
 
   const resolveResult = (id: string, resolved: string) => {
@@ -87,6 +89,9 @@ export function esbuildDepPlugin(
         namespace: 'browser-external'
       }
     }
+    if (ssr && isBuiltin(resolved)) {
+      return
+    }
     if (isExternalUrl(resolved)) {
       return {
         path: resolved,

packages/vite/src/node/optimizer/index.ts

@@ -26,7 +26,11 @@ import { transformWithEsbuild } from '../plugins/esbuild'
 import { ESBUILD_MODULES_TARGET } from '../constants'
 import { esbuildDepPlugin } from './esbuildDepPlugin'
 import { scanImports } from './scan'
-export { initDepsOptimizer, getDepsOptimizer } from './optimizer'
+export {
+  initDepsOptimizer,
+  initDevSsrDepsOptimizer,
+  getDepsOptimizer
+} from './optimizer'
 
 export const debuggerViteDeps = createDebugger('vite:deps')
 const debug = debuggerViteDeps
@@ -47,7 +51,7 @@ export type ExportsData = {
 }
 
 export interface DepsOptimizer {
-  metadata: (options: { ssr: boolean }) => DepOptimizationMetadata
+  metadata: DepOptimizationMetadata
   scanProcessing?: Promise<void>
   registerMissingImport: (
     id: string,
@@ -546,6 +550,9 @@ export async function runOptimizeDeps(
       : JSON.stringify(process.env.NODE_ENV || config.mode)
   }
 
+  const platform =
+    ssr && config.ssr?.target !== 'webworker' ? 'node' : 'browser'
+
   const start = performance.now()
 
   const result = await build({
@@ -555,9 +562,16 @@ export async function runOptimizeDeps(
     // We can't use platform 'neutral', as esbuild has custom handling
     // when the platform is 'node' or 'browser' that can't be emulated
     // by using mainFields and conditions
-    platform: ssr && config.ssr?.target !== 'webworker' ? 'node' : 'browser',
+    platform,
     define,
     format: 'esm',
+    // See https://github.com/evanw/esbuild/issues/1921#issuecomment-1152991694
+    banner:
+      platform === 'node'
+        ? {
+            js: `import { createRequire } from 'module';const require = createRequire(import.meta.url);`
+          }
+        : undefined,
     target: isBuild ? config.build.target || undefined : ESBUILD_MODULES_TARGET,
     external: config.optimizeDeps?.exclude,
     logLevel: 'error',
@@ -568,7 +582,7 @@ export async function runOptimizeDeps(
     metafile: true,
     plugins: [
       ...plugins,
-      esbuildDepPlugin(flatIdDeps, flatIdToExports, config)
+      esbuildDepPlugin(flatIdDeps, flatIdToExports, config, ssr)
     ],
     ...esbuildOptions,
     supported: {

packages/vite/src/node/optimizer/optimizer.ts

@@ -24,7 +24,6 @@ import {
   runOptimizeDeps
 } from '.'
 import type {
-  DepOptimizationMetadata,
   DepOptimizationProcessing,
   DepsOptimizer,
   OptimizedDepInfo
@@ -39,18 +38,36 @@ const isDebugEnabled = _debug('vite:deps').enabled
 const debounceMs = 100
 
 const depsOptimizerMap = new WeakMap<ResolvedConfig, DepsOptimizer>()
+const devSsrDepsOptimizerMap = new WeakMap<ResolvedConfig, DepsOptimizer>()
 
 export function getDepsOptimizer(
-  config: ResolvedConfig
+  config: ResolvedConfig,
+  type: { ssr?: boolean }
 ): DepsOptimizer | undefined {
   // Workers compilation shares the DepsOptimizer from the main build
-  return depsOptimizerMap.get(config.mainConfig || config)
+  const isDevSsr = type.ssr && config.command !== 'build'
+  return (isDevSsr ? devSsrDepsOptimizerMap : depsOptimizerMap).get(
+    config.mainConfig || config
+  )
 }
 
 export async function initDepsOptimizer(
   config: ResolvedConfig,
   server?: ViteDevServer
-): Promise<DepsOptimizer> {
+): Promise<void> {
+  await createDepsOptimizer(config, server)
+}
+
+export async function initDevSsrDepsOptimizer(
+  config: ResolvedConfig
+): Promise<void> {
+  await createDevSsrDepsOptimizer(config)
+}
+
+async function createDepsOptimizer(
+  config: ResolvedConfig,
+  server?: ViteDevServer
+): Promise<void> {
   const { logger } = config
   const isBuild = config.command === 'build'
 
@@ -62,18 +79,11 @@ export async function initDepsOptimizer(
 
   let handle: NodeJS.Timeout | undefined
 
-  let ssrServerDepsMetadata: DepOptimizationMetadata
-  let _metadata =
+  let metadata =
     cachedMetadata || initDepsOptimizerMetadata(config, sessionTimestamp)
 
   const depsOptimizer: DepsOptimizer = {
-    metadata: (options: { ssr: boolean }) => {
-      if (isBuild || !options.ssr) {
-        return _metadata
-      } else {
-        return ssrServerDepsMetadata
-      }
-    },
+    metadata,
     registerMissingImport,
     run: () => debouncedProcessing(0),
     isOptimizedDepFile: (id: string) => isOptimizedDepFile(id, config),
@@ -89,10 +99,6 @@ export async function initDepsOptimizer(
 
   depsOptimizerMap.set(config, depsOptimizer)
 
-  if (!isBuild && config.ssr) {
-    ssrServerDepsMetadata = await optimizeServerSsrDeps(config)
-  }
-
   let newDepsDiscovered = false
 
   let newDepsToLog: string[] = []
@@ -137,7 +143,6 @@ export async function initDepsOptimizer(
         config,
         sessionTimestamp
       )
-      const metadata = _metadata
       for (const depInfo of Object.values(discovered)) {
         addOptimizedDepInfo(metadata, 'discovered', {
           ...depInfo,
@@ -155,8 +160,6 @@ export async function initDepsOptimizer(
         try {
           debug(colors.green(`scanning for dependencies...`))
 
-          const metadata = _metadata
-
           const discovered = await discoverProjectDependencies(
             config,
             sessionTimestamp
@@ -201,7 +204,7 @@ export async function initDepsOptimizer(
     // Ensure that a rerun will not be issued for current discovered deps
     if (handle) clearTimeout(handle)
 
-    if (Object.keys(_metadata.discovered).length === 0) {
+    if (Object.keys(metadata.discovered).length === 0) {
       currentlyProcessing = false
       return
     }
@@ -217,8 +220,6 @@ export async function initDepsOptimizer(
     // if the rerun fails, _metadata remains untouched, current discovered
     // deps are cleaned, and a fullReload is issued
 
-    let metadata = _metadata
-
     // All deps, previous known and newly discovered are rebundled,
     // respect insertion order to keep the metadata file stable
 
@@ -324,7 +325,7 @@ export async function initDepsOptimizer(
           )
         }
 
-        metadata = _metadata = newData
+        metadata = depsOptimizer.metadata = newData
         resolveEnqueuedProcessingPromises()
       }
 
@@ -418,7 +419,7 @@ export async function initDepsOptimizer(
     // debounce time to wait for new missing deps finished, issue a new
     // optimization of deps (both old and newly found) once the previous
     // optimizeDeps processing is finished
-    const deps = Object.keys(_metadata.discovered)
+    const deps = Object.keys(metadata.discovered)
     const depsString = depsLogString(deps)
     debug(colors.green(`new dependencies found: ${depsString}`))
     runOptimizer()
@@ -449,7 +450,6 @@ export async function initDepsOptimizer(
         `Error: ${id} is a missing dependency in SSR dev server, it needs to be added to optimizeDeps.include`
       )
     }
-    const metadata = _metadata
     const optimized = metadata.optimized[id]
     if (optimized) {
       return optimized
@@ -539,7 +539,7 @@ export async function initDepsOptimizer(
     if (!firstRunEnsured && !firstRunCalled && registeredIds.length === 0) {
       setTimeout(() => {
         if (!firstRunCalled && registeredIds.length === 0) {
-          getDepsOptimizer(config)?.run()
+          debouncedProcessing(0) // queue the optimizer run
         }
       }, runOptimizerIfIdleAfterMs)
     }
@@ -580,7 +580,7 @@ export async function initDepsOptimizer(
             if (registeredIds.length > 0) {
               runOptimizerWhenIdle()
             } else {
-              getDepsOptimizer(config)?.run()
+              debouncedProcessing(0) // queue the optimizer run
             }
           }
         }
@@ -596,8 +596,34 @@ export async function initDepsOptimizer(
       }
     }
   }
+}
 
-  return depsOptimizer
+async function createDevSsrDepsOptimizer(
+  config: ResolvedConfig
+): Promise<void> {
+  const metadata = await optimizeServerSsrDeps(config)
+  const depsOptimizer = {
+    metadata,
+    isOptimizedDepFile: (id: string) => isOptimizedDepFile(id, config),
+    isOptimizedDepUrl: createIsOptimizedDepUrl(config),
+    getOptimizedDepId: (depInfo: OptimizedDepInfo) =>
+      `${depInfo.file}?v=${depInfo.browserHash}`,
+
+    registerMissingImport: () => {
+      throw new Error(
+        'Vite Internal Error: registerMissingImport is not supported in dev SSR'
+      )
+    },
+    // noop, there is no scanning during dev SSR
+    // the optimizer blocks the server start
+    run: () => {},
+    registerWorkersSource: (id: string) => {},
+    delayDepsOptimizerUntil: (id: string, done: () => Promise<any>) => {},
+    resetRegisteredIds: () => {},
+    ensureFirstRun: () => {},
+    options: config.optimizeDeps
+  }
+  devSsrDepsOptimizerMap.set(config, depsOptimizer)
 }
 
 export async function preTransformOptimizeDepsEntries(

packages/vite/src/node/plugins/importAnalysis.ts

@@ -214,7 +214,7 @@ export function importAnalysisPlugin(config: ResolvedConfig): Plugin {
         )
       }
 
-      const depsOptimizer = getDepsOptimizer(config)
+      const depsOptimizer = getDepsOptimizer(config, { ssr })
 
       const { moduleGraph } = server
       // since we are already in the transform phase of the importer, it must
@@ -275,8 +275,7 @@ export function importAnalysisPlugin(config: ResolvedConfig): Plugin {
             // the dependency needs to be resolved starting from the original source location of the optimized file
             // because starting from node_modules/.vite will not find the dependency if it was not hoisted
             // (that is, if it is under node_modules directory in the package source of the optimized file)
-            for (const optimizedModule of depsOptimizer.metadata({ ssr })
-              .depInfoList) {
+            for (const optimizedModule of depsOptimizer.metadata.depInfoList) {
               if (!optimizedModule.src) continue // Ignore chunks
               if (optimizedModule.file === importerModule.file) {
                 importerFile = optimizedModule.src
@@ -479,7 +478,7 @@ export function importAnalysisPlugin(config: ResolvedConfig): Plugin {
               const file = cleanUrl(resolvedId) // Remove ?v={hash}
 
               const needsInterop = await optimizedDepNeedsInterop(
-                depsOptimizer.metadata({ ssr }),
+                depsOptimizer.metadata,
                 file,
                 config
               )

packages/vite/src/node/plugins/importAnalysisBuild.ts

@@ -154,7 +154,7 @@ export function buildImportAnalysisPlugin(config: ResolvedConfig): Plugin {
       }
 
       const { root } = config
-      const depsOptimizer = getDepsOptimizer(config)
+      const depsOptimizer = getDepsOptimizer(config, { ssr })
 
       const normalizeUrl = async (
         url: string,
@@ -170,8 +170,7 @@ export function buildImportAnalysisPlugin(config: ResolvedConfig): Plugin {
             // the dependency needs to be resolved starting from the original source location of the optimized file
             // because starting from node_modules/.vite will not find the dependency if it was not hoisted
             // (that is, if it is under node_modules directory in the package source of the optimized file)
-            for (const optimizedModule of depsOptimizer.metadata({ ssr })
-              .depInfoList) {
+            for (const optimizedModule of depsOptimizer.metadata.depInfoList) {
               if (!optimizedModule.src) continue // Ignore chunks
               if (optimizedModule.file === importer) {
                 importerFile = optimizedModule.src
@@ -262,7 +261,7 @@ export function buildImportAnalysisPlugin(config: ResolvedConfig): Plugin {
               const file = cleanUrl(resolvedId) // Remove ?v={hash}
 
               const needsInterop = await optimizedDepNeedsInterop(
-                depsOptimizer.metadata({ ssr }),
+                depsOptimizer.metadata,
                 file,
                 config
               )

packages/vite/src/node/plugins/index.ts

@@ -62,7 +62,8 @@ export async function resolvePlugins(
       packageCache: config.packageCache,
       ssrConfig: config.ssr,
       asSrc: true,
-      getDepsOptimizer: () => getDepsOptimizer(config),
+      getDepsOptimizer: (type: { ssr?: boolean }) =>
+        getDepsOptimizer(config, type),
       shouldExternalize:
         isBuild && config.build.ssr && config.ssr?.format !== 'cjs'
           ? (id) => shouldExternalizeForSSR(id, config)

packages/vite/src/node/plugins/optimizedDeps.ts

@@ -17,8 +17,8 @@ export function optimizedDepsPlugin(config: ResolvedConfig): Plugin {
   return {
     name: 'vite:optimized-deps',
 
-    async resolveId(id) {
-      if (getDepsOptimizer(config)?.isOptimizedDepFile(id)) {
+    async resolveId(id, source, { ssr }) {
+      if (getDepsOptimizer(config, { ssr })?.isOptimizedDepFile(id)) {
         return id
       }
     },
@@ -28,51 +28,49 @@ export function optimizedDepsPlugin(config: ResolvedConfig): Plugin {
     // is in importAnalysis, see call to delayDepsOptimizerUntil
 
     async load(id, options) {
-      const ssr = options?.ssr ?? false
-      const depsOptimizer = getDepsOptimizer(config)
+      const ssr = options?.ssr === true
+      const depsOptimizer = getDepsOptimizer(config, { ssr })
       if (depsOptimizer?.isOptimizedDepFile(id)) {
-        const metadata = depsOptimizer?.metadata({ ssr })
-        if (metadata) {
-          const file = cleanUrl(id)
-          const versionMatch = id.match(DEP_VERSION_RE)
-          const browserHash = versionMatch
-            ? versionMatch[1].split('=')[1]
-            : undefined
-
-          // Search in both the currently optimized and newly discovered deps
-          const info = optimizedDepInfoFromFile(metadata, file)
-          if (info) {
-            if (browserHash && info.browserHash !== browserHash) {
-              throwOutdatedRequest(id)
-            }
-            try {
-              // This is an entry point, it may still not be bundled
-              await info.processing
-            } catch {
-              // If the refresh has not happened after timeout, Vite considers
-              // something unexpected has happened. In this case, Vite
-              // returns an empty response that will error.
-              throwProcessingError(id)
-              return
-            }
-            const newMetadata = depsOptimizer.metadata({ ssr })
-            if (metadata !== newMetadata) {
-              const currentInfo = optimizedDepInfoFromFile(newMetadata!, file)
-              if (info.browserHash !== currentInfo?.browserHash) {
-                throwOutdatedRequest(id)
-              }
-            }
+        const metadata = depsOptimizer.metadata
+        const file = cleanUrl(id)
+        const versionMatch = id.match(DEP_VERSION_RE)
+        const browserHash = versionMatch
+          ? versionMatch[1].split('=')[1]
+          : undefined
+
+        // Search in both the currently optimized and newly discovered deps
+        const info = optimizedDepInfoFromFile(metadata, file)
+        if (info) {
+          if (browserHash && info.browserHash !== browserHash) {
+            throwOutdatedRequest(id)
           }
-          isDebug && debug(`load ${colors.cyan(file)}`)
-          // Load the file from the cache instead of waiting for other plugin
-          // load hooks to avoid race conditions, once processing is resolved,
-          // we are sure that the file has been properly save to disk
           try {
-            return await fs.readFile(file, 'utf-8')
-          } catch (e) {
-            // Outdated non-entry points (CHUNK), loaded after a rerun
-            throwOutdatedRequest(id)
+            // This is an entry point, it may still not be bundled
+            await info.processing
+          } catch {
+            // If the refresh has not happened after timeout, Vite considers
+            // something unexpected has happened. In this case, Vite
+            // returns an empty response that will error.
+            throwProcessingError(id)
+            return
           }
+          const newMetadata = depsOptimizer.metadata
+          if (metadata !== newMetadata) {
+            const currentInfo = optimizedDepInfoFromFile(newMetadata!, file)
+            if (info.browserHash !== currentInfo?.browserHash) {
+              throwOutdatedRequest(id)
+            }
+          }
+        }
+        isDebug && debug(`load ${colors.cyan(file)}`)
+        // Load the file from the cache instead of waiting for other plugin
+        // load hooks to avoid race conditions, once processing is resolved,
+        // we are sure that the file has been properly save to disk
+        try {
+          return await fs.readFile(file, 'utf-8')
+        } catch (e) {
+          // Outdated non-entry points (CHUNK), loaded after a rerun
+          throwOutdatedRequest(id)
         }
       }
     }
@@ -85,27 +83,32 @@ export function optimizedDepsBuildPlugin(config: ResolvedConfig): Plugin {
 
     buildStart() {
       if (!config.isWorker) {
-        getDepsOptimizer(config)?.resetRegisteredIds()
+        // This will be run for the current active optimizer, during build
+        // it will be the SSR optimizer if config.build.ssr is defined
+        getDepsOptimizer(config, { ssr: undefined })?.resetRegisteredIds()
       }
     },
 
-    async resolveId(id) {
-      if (getDepsOptimizer(config)?.isOptimizedDepFile(id)) {
+    async resolveId(id, importer, { ssr }) {
+      if (getDepsOptimizer(config, { ssr })?.isOptimizedDepFile(id)) {
         return id
       }
     },
 
-    transform(_code, id) {
-      getDepsOptimizer(config)?.delayDepsOptimizerUntil(id, async () => {
-        await this.load({ id })
-      })
+    transform(_code, id, options) {
+      const ssr = options?.ssr === true
+      getDepsOptimizer(config, { ssr })?.delayDepsOptimizerUntil(
+        id,
+        async () => {
+          await this.load({ id })
+        }
+      )
     },
 
     async load(id, options) {
-      const ssr = options?.ssr ?? false
-      const depsOptimizer = getDepsOptimizer(config)
-      const metadata = depsOptimizer?.metadata({ ssr })
-      if (!metadata || !depsOptimizer?.isOptimizedDepFile(id)) {
+      const ssr = options?.ssr === true
+      const depsOptimizer = getDepsOptimizer(config, { ssr })
+      if (!depsOptimizer?.isOptimizedDepFile(id)) {
         return
       }
 
@@ -114,7 +117,7 @@ export function optimizedDepsBuildPlugin(config: ResolvedConfig): Plugin {
       const file = cleanUrl(id)
       // Search in both the currently optimized and newly discovered deps
       // If all the inputs are dependencies, we aren't going to get any
-      const info = optimizedDepInfoFromFile(metadata, file)
+      const info = optimizedDepInfoFromFile(depsOptimizer.metadata, file)
       if (info) {
         try {
           // This is an entry point, it may still not be bundled

packages/vite/src/node/plugins/preAlias.ts

@@ -11,10 +11,10 @@ export function preAliasPlugin(config: ResolvedConfig): Plugin {
   return {
     name: 'vite:pre-alias',
     async resolveId(id, importer, options) {
-      const ssr = options?.ssr ?? false
-      const depsOptimizer = getDepsOptimizer(config)
+      const ssr = options?.ssr === true
+      const depsOptimizer = getDepsOptimizer(config, { ssr })
       if (depsOptimizer && bareImportRE.test(id) && !options?.scan) {
-        return await tryOptimizedResolve(depsOptimizer, ssr, id, importer)
+        return await tryOptimizedResolve(depsOptimizer, id, importer)
       }
     }
   }

packages/vite/src/node/plugins/resolve.ts

@@ -83,7 +83,7 @@ export interface InternalResolveOptions extends ResolveOptions {
   // True when resolving during the scan phase to discover dependencies
   scan?: boolean
   // Resolve using esbuild deps optimization
-  getDepsOptimizer?: () => DepsOptimizer | undefined
+  getDepsOptimizer?: (type: { ssr?: boolean }) => DepsOptimizer | undefined
   shouldExternalize?: (id: string) => boolean | undefined
 }
 
@@ -102,11 +102,11 @@ export function resolvePlugin(resolveOptions: InternalResolveOptions): Plugin {
     name: 'vite:resolve',
 
     async resolveId(id, importer, resolveOpts) {
+      const ssr = resolveOpts?.ssr === true
+
       // We need to delay depsOptimizer until here instead of passing it as an option
       // the resolvePlugin because the optimizer is created on server listen during dev
-      const depsOptimizer = resolveOptions.getDepsOptimizer?.()
-
-      const ssr = resolveOpts?.ssr === true
+      const depsOptimizer = resolveOptions.getDepsOptimizer?.({ ssr })
 
       if (id.startsWith(browserExternalId)) {
         return id
@@ -186,7 +186,7 @@ export function resolvePlugin(resolveOptions: InternalResolveOptions): Plugin {
           // Inject the current browserHash version if the path doesn't have one
           if (!normalizedFsPath.match(DEP_VERSION_RE)) {
             const browserHash = optimizedDepInfoFromFile(
-              depsOptimizer.metadata({ ssr }),
+              depsOptimizer.metadata,
               normalizedFsPath
             )?.browserHash
             if (browserHash) {
@@ -269,7 +269,7 @@ export function resolvePlugin(resolveOptions: InternalResolveOptions): Plugin {
           asSrc &&
           depsOptimizer &&
           !options.scan &&
-          (res = await tryOptimizedResolve(depsOptimizer, ssr, id, importer))
+          (res = await tryOptimizedResolve(depsOptimizer, id, importer))
         ) {
           return res
         }
@@ -690,7 +690,7 @@ export function tryNodeResolve(
     // otherwise we may introduce duplicated modules for externalized files
     // from pre-bundled deps.
     if (!isBuild) {
-      const versionHash = depsOptimizer.metadata({ ssr }).browserHash
+      const versionHash = depsOptimizer.metadata.browserHash
       if (versionHash && isJsType) {
         resolved = injectQuery(resolved, `v=${versionHash}`)
       }
@@ -716,16 +716,12 @@ export function tryNodeResolve(
 
 export async function tryOptimizedResolve(
   depsOptimizer: DepsOptimizer,
-  ssr: boolean,
   id: string,
   importer?: string
 ): Promise<string | undefined> {
   await depsOptimizer.scanProcessing
 
-  const metadata = depsOptimizer.metadata({ ssr })
-  if (!metadata) {
-    return
-  }
+  const metadata = depsOptimizer.metadata
 
   const depInfo = optimizedDepInfoFromId(metadata, id)
   if (depInfo) {

packages/vite/src/node/plugins/worker.ts

@@ -222,7 +222,8 @@ export function webWorkerPlugin(config: ResolvedConfig): Plugin {
       }
     },
 
-    async transform(raw, id) {
+    async transform(raw, id, options) {
+      const ssr = options?.ssr === true
       const query = parseRequest(id)
       if (query && query[WORKER_FILE_ID] != null) {
         // if import worker by worker constructor will had query.type
@@ -269,7 +270,7 @@ export function webWorkerPlugin(config: ResolvedConfig): Plugin {
         : 'module'
       const workerOptions = workerType === 'classic' ? '' : ',{type: "module"}'
       if (isBuild) {
-        getDepsOptimizer(config)?.registerWorkersSource(id)
+        getDepsOptimizer(config, { ssr })?.registerWorkersSource(id)
         if (query.inline != null) {
           const chunk = await bundleWorkerEntry(config, id, query)
           // inline as blob data url

packages/vite/src/node/plugins/workerImportMetaUrl.ts

@@ -76,6 +76,7 @@ export function workerImportMetaUrlPlugin(config: ResolvedConfig): Plugin {
     name: 'vite:worker-import-meta-url',
 
     async transform(code, id, options) {
+      const ssr = options?.ssr === true
       if (
         !options?.ssr &&
         (code.includes('new Worker') || code.includes('new SharedWorker')) &&
@@ -117,7 +118,7 @@ export function workerImportMetaUrlPlugin(config: ResolvedConfig): Plugin {
 
           let url: string
           if (isBuild) {
-            getDepsOptimizer(config)?.registerWorkersSource(id)
+            getDepsOptimizer(config, { ssr })?.registerWorkersSource(id)
             url = await workerFileToUrl(config, file, query)
           } else {
             url = await fileToUrl(cleanUrl(file), config, this)

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

@@ -28,7 +28,11 @@ import {
   ssrRewriteStacktrace
 } from '../ssr/ssrStacktrace'
 import { ssrTransform } from '../ssr/ssrTransform'
-import { getDepsOptimizer, initDepsOptimizer } from '../optimizer'
+import {
+  getDepsOptimizer,
+  initDepsOptimizer,
+  initDevSsrDepsOptimizer
+} from '../optimizer'
 import { CLIENT_DIR } from '../constants'
 import type { Logger } from '../logger'
 import { printCommonServerUrls } from '../logger'
@@ -306,6 +310,8 @@ export async function createServer(
 
   let exitProcess: () => void
 
+  let creatingDevSsrOptimizer: Promise<void> | null = null
+
   const server: ViteDevServer = {
     config,
     middlewares,
@@ -324,6 +330,13 @@ export async function createServer(
     },
     transformIndexHtml: null!, // to be immediately set
     async ssrLoadModule(url, opts?: { fixStacktrace?: boolean }) {
+      if (!getDepsOptimizer(config, { ssr: true })) {
+        if (!creatingDevSsrOptimizer) {
+          creatingDevSsrOptimizer = initDevSsrDepsOptimizer(config)
+        }
+        await creatingDevSsrOptimizer
+        creatingDevSsrOptimizer = null
+      }
       await updateCjsSsrExternals(server)
       return ssrLoadModule(
         url,
@@ -752,15 +765,21 @@ async function restartServer(server: ViteDevServer) {
 
 async function updateCjsSsrExternals(server: ViteDevServer) {
   if (!server._ssrExternals) {
-    // We use the non-ssr optimized deps to find known imports
     let knownImports: string[] = []
-    const depsOptimizer = getDepsOptimizer(server.config)
+
+    // Important! We use the non-ssr optimized deps to find known imports
+    // Only the explicitly defined deps are optimized during dev SSR, so
+    // we use the generated list from the scanned deps in regular dev.
+    // This is part of the v2 externalization heuristics and it is kept
+    // for backwards compatibility in case user needs to fallback to the
+    // legacy scheme. It may be removed in a future v3 minor.
+    const depsOptimizer = getDepsOptimizer(server.config, { ssr: false })
+
     if (depsOptimizer) {
       await depsOptimizer.scanProcessing
-      const metadata = depsOptimizer.metadata({ ssr: false })
       knownImports = [
-        ...Object.keys(metadata.optimized),
-        ...Object.keys(metadata.discovered)
+        ...Object.keys(depsOptimizer.metadata.optimized),
+        ...Object.keys(depsOptimizer.metadata.discovered)
       ]
     }
     server._ssrExternals = cjsSsrResolveExternals(server.config, knownImports)

packages/vite/src/node/server/middlewares/transform.ts

@@ -71,7 +71,11 @@ export function transformMiddleware(
       const isSourceMap = withoutQuery.endsWith('.map')
       // since we generate source map references, handle those requests here
       if (isSourceMap) {
-        if (getDepsOptimizer(server.config)?.isOptimizedDepUrl(url)) {
+        if (
+          getDepsOptimizer(server.config, { ssr: false })?.isOptimizedDepUrl(
+            url
+          )
+        ) {
           // If the browser is requesting a source map for an optimized dep, it
           // means that the dependency has already been pre-bundled and loaded
           const mapFile = url.startsWith(FS_PREFIX)
@@ -188,7 +192,9 @@ export function transformMiddleware(
           const type = isDirectCSSRequest(url) ? 'css' : 'js'
           const isDep =
             DEP_VERSION_RE.test(url) ||
-            getDepsOptimizer(server.config)?.isOptimizedDepUrl(url)
+            getDepsOptimizer(server.config, { ssr: false })?.isOptimizedDepUrl(
+              url
+            )
           return send(req, res, result.code, type, {
             etag: result.etag,
             // allow browser to cache npm deps!

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

@@ -145,7 +145,7 @@ async function doTransform(
 
   const result = loadAndTransform(id, url, server, options, timestamp)
 
-  const depsOptimizer = getDepsOptimizer(config)
+  const depsOptimizer = getDepsOptimizer(config, { ssr })
   if (depsOptimizer && !config.legacy?.devDepsScanner) {
     depsOptimizer.delayDepsOptimizerUntil(id, () => result)
   }

playground/ssr-deps/import-builtin-cjs/index.js

@@ -0,0 +1,5 @@
+exports.stream = require('stream')
+
+exports.hello = function () {
+  return 'Hello World!'
+}

playground/ssr-deps/import-builtin-cjs/package.json

@@ -0,0 +1,6 @@
+{
+  "name": "import-builtin",
+  "private": true,
+  "type": "commonjs",
+  "version": "0.0.0"
+}

playground/ssr-deps/no-external-cjs/package.json

@@ -1,5 +1,5 @@
 {
-  "name": "primitive-export",
+  "name": "no-external-cjs",
   "private": true,
   "type": "commonjs",
   "version": "0.0.0"

playground/ssr-deps/package.json

@@ -20,6 +20,7 @@
     "require-absolute": "file:./require-absolute",
     "ts-transpiled-exports": "file:./ts-transpiled-exports",
     "no-external-cjs": "file:./no-external-cjs",
+    "import-builtin-cjs": "file:./import-builtin-cjs",
     "no-external-css": "file:./no-external-css"
   },
   "devDependencies": {

playground/ssr-deps/server.js

@@ -35,7 +35,7 @@ export async function createServer(root = process.cwd(), hmrPort) {
     },
     appType: 'custom',
     ssr: {
-      noExternal: ['no-external-cjs', 'no-external-css']
+      noExternal: ['no-external-cjs', 'import-builtin-cjs', 'no-external-css']
     }
   })
   // use vite's connect instance as middleware

playground/ssr-deps/src/app.js

@@ -10,6 +10,7 @@ import definePropertyExports from 'define-property-exports'
 import onlyObjectAssignedExports from 'only-object-assigned-exports'
 import requireAbsolute from 'require-absolute'
 import noExternalCjs from 'no-external-cjs'
+import importBuiltinCjs from 'import-builtin-cjs'
 
 export async function render(url, rootDir) {
   let html = ''
@@ -49,5 +50,8 @@ export async function render(url, rootDir) {
   const noExternalCjsMessage = noExternalCjs.hello()
   html += `\n<p class="no-external-cjs-msg">message from no-external-cjs: ${noExternalCjsMessage}</p>`
 
+  const importBuiltinCjsMessage = importBuiltinCjs.hello()
+  html += `\n<p class="import-builtin-cjs-msg">message from import-builtin-cjs: ${importBuiltinCjsMessage}</p>`
+
   return html + '\n'
 }