refactor: use simpler resolve for nested optimized deps

packages/vite/package.json

@@ -68,7 +68,6 @@
   "dependencies": {
     "esbuild": "^0.17.5",
     "postcss": "^8.4.21",
-    "resolve": "^1.22.1",
     "rollup": "^3.20.2"
   },
   "optionalDependencies": {

packages/vite/rollup.config.ts

@@ -120,6 +120,13 @@ function createNodePlugins(
           pattern: /^var json = typeof JSON.+require\('jsonify'\);$/gm,
           replacement: 'var json = JSON',
         },
+        // postcss-import uses the `resolve` dep if the `resolve` option is not passed.
+        // However, we always pass the `resolve` option. Remove this import to avoid
+        // bundling the `resolve` dep.
+        'postcss-import/index.js': {
+          src: 'const resolveId = require("./lib/resolve-id")',
+          replacement: 'const resolveId = undefined',
+        },
       }),
 
     commonjs({

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

@@ -43,6 +43,8 @@ export function preAliasPlugin(config: ResolvedConfig): Plugin {
             depsOptimizer,
             id,
             importer,
+            config.resolve.preserveSymlinks,
+            config.packageCache,
           )
           if (optimizedId) {
             return optimizedId // aliased dep already optimized

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

@@ -32,7 +32,6 @@ import {
   isTsRequest,
   isWindows,
   normalizePath,
-  resolveFrom,
   safeRealpathSync,
   slash,
   tryStatSync,
@@ -318,7 +317,13 @@ export function resolvePlugin(resolveOptions: InternalResolveOptions): Plugin {
           asSrc &&
           depsOptimizer &&
           !options.scan &&
-          (res = await tryOptimizedResolve(depsOptimizer, id, importer))
+          (res = await tryOptimizedResolve(
+            depsOptimizer,
+            id,
+            importer,
+            options.preserveSymlinks,
+            options.packageCache,
+          ))
         ) {
           return res
         }
@@ -854,6 +859,8 @@ export async function tryOptimizedResolve(
   depsOptimizer: DepsOptimizer,
   id: string,
   importer?: string,
+  preserveSymlinks?: boolean,
+  packageCache?: PackageCache,
 ): Promise<string | undefined> {
   // TODO: we need to wait until scanning is done here as this function
   // is used in the preAliasPlugin to decide if an aliased dep is optimized,
@@ -871,31 +878,31 @@ export async function tryOptimizedResolve(
   if (!importer) return
 
   // further check if id is imported by nested dependency
-  let resolvedSrc: string | undefined
+  let idPkgDir: string | undefined
+  const nestedIdMatch = `> ${id}`
 
   for (const optimizedData of metadata.depInfoList) {
     if (!optimizedData.src) continue // Ignore chunks
 
-    const pkgPath = optimizedData.id
-    // check for scenarios, e.g.
-    //   pkgPath  => "my-lib > foo"
-    //   id       => "foo"
-    // this narrows the need to do a full resolve
-    if (!pkgPath.endsWith(id)) continue
+    // check where "foo" is nested in "my-lib > foo"
+    if (!optimizedData.id.endsWith(nestedIdMatch)) continue
 
-    // lazily initialize resolvedSrc
-    if (resolvedSrc == null) {
-      try {
-        // this may throw errors if unable to resolve, e.g. aliased id
-        resolvedSrc = normalizePath(resolveFrom(id, path.dirname(importer)))
-      } catch {
-        // this is best-effort only so swallow errors
-        break
-      }
+    // lazily initialize idPkgDir
+    if (idPkgDir == null) {
+      idPkgDir = resolvePackageData(
+        id,
+        importer,
+        preserveSymlinks,
+        packageCache,
+      )?.dir
+      // if still null, it likely means that this id isn't a dep for importer.
+      // break to bail early
+      if (idPkgDir == null) break
+      idPkgDir = normalizePath(idPkgDir)
     }
 
     // match by src to correctly identify if id belongs to nested dependency
-    if (optimizedData.src === resolvedSrc) {
+    if (optimizedData.src.startsWith(idPkgDir)) {
       return depsOptimizer.getOptimizedDepId(optimizedData)
     }
   }

packages/vite/src/node/utils.ts

@@ -8,7 +8,6 @@ import { builtinModules, createRequire } from 'node:module'
 import { promises as dns } from 'node:dns'
 import { performance } from 'node:perf_hooks'
 import type { AddressInfo, Server } from 'node:net'
-import resolve from 'resolve'
 import type { FSWatcher } from 'chokidar'
 import remapping from '@ampproject/remapping'
 import type { DecodedSourceMap, RawSourceMap } from '@ampproject/remapping'
@@ -22,7 +21,6 @@ import { createFilter as _createFilter } from '@rollup/pluginutils'
 import {
   CLIENT_ENTRY,
   CLIENT_PUBLIC_PATH,
-  DEFAULT_EXTENSIONS,
   ENV_PUBLIC_PATH,
   FS_PREFIX,
   NULL_BYTE_PLACEHOLDER,
@@ -145,23 +143,6 @@ export const deepImportRE = /^([^@][^/]*)\/|^(@[^/]+\/[^/]+)\//
 // TODO: use import()
 const _require = createRequire(import.meta.url)
 
-const ssrExtensions = ['.js', '.cjs', '.json', '.node']
-
-export function resolveFrom(
-  id: string,
-  basedir: string,
-  preserveSymlinks = false,
-  ssr = false,
-): string {
-  return resolve.sync(id, {
-    basedir,
-    paths: [],
-    extensions: ssr ? ssrExtensions : DEFAULT_EXTENSIONS,
-    // necessary to work with pnpm
-    preserveSymlinks: preserveSymlinks || !!process.versions.pnp || false,
-  })
-}
-
 // set in bin/vite.js
 const filter = process.env.VITE_DEBUG_FILTER