fix: respect mainFields when resolving browser/module field (fixes #8659) (#10071)

Author: sapphi-red

docs/config/shared-options.md

@@ -158,6 +158,16 @@ Export keys ending with "/" is deprecated by Node and may not work well. Please
 
 List of fields in `package.json` to try when resolving a package's entry point. Note this takes lower precedence than conditional exports resolved from the `exports` field: if an entry point is successfully resolved from `exports`, the main field will be ignored.
 
+## resolve.browserField
+
+- **Type:** `boolean`
+- **Default:** `true`
+- **Deprecated**
+
+Whether to enable resolving to `browser` field.
+
+In future, `resolve.mainFields`'s default value will be `['browser', 'module', 'jsnext:main', 'jsnext']` and this option will be removed.
+
 ## resolve.extensions
 
 - **Type:** `string[]`

packages/vite/src/node/config.ts

@@ -43,6 +43,8 @@ import {
   CLIENT_ENTRY,
   DEFAULT_ASSETS_RE,
   DEFAULT_CONFIG_FILES,
+  DEFAULT_EXTENSIONS,
+  DEFAULT_MAIN_FIELDS,
   ENV_ENTRY
 } from './constants'
 import type { InternalResolveOptions, ResolveOptions } from './plugins/resolve'
@@ -321,7 +323,7 @@ export type ResolvedConfig = Readonly<
     mainConfig: ResolvedConfig | null
     isProduction: boolean
     env: Record<string, any>
-    resolve: ResolveOptions & {
+    resolve: Required<ResolveOptions> & {
       alias: Alias[]
     }
     plugins: readonly Plugin[]
@@ -474,7 +476,12 @@ export async function resolveConfig(
   )
 
   const resolveOptions: ResolvedConfig['resolve'] = {
-    ...config.resolve,
+    mainFields: config.resolve?.mainFields ?? DEFAULT_MAIN_FIELDS,
+    browserField: config.resolve?.browserField ?? true,
+    conditions: config.resolve?.conditions ?? [],
+    extensions: config.resolve?.extensions ?? DEFAULT_EXTENSIONS,
+    dedupe: config.resolve?.dedupe ?? [],
+    preserveSymlinks: config.resolve?.preserveSymlinks ?? false,
     alias: resolvedAlias
   }
 
@@ -581,8 +588,8 @@ export async function resolveConfig(
   const server = resolveServerOptions(resolvedRoot, config.server, logger)
   const ssr = resolveSSROptions(
     config.ssr,
-    config.legacy?.buildSsrCjsExternalHeuristics,
-    config.resolve?.preserveSymlinks
+    resolveOptions.preserveSymlinks,
+    config.legacy?.buildSsrCjsExternalHeuristics
   )
 
   const middlewareMode = config?.server?.middlewareMode
@@ -649,7 +656,7 @@ export async function resolveConfig(
       disabled: 'build',
       ...optimizeDeps,
       esbuildOptions: {
-        preserveSymlinks: config.resolve?.preserveSymlinks,
+        preserveSymlinks: resolveOptions.preserveSymlinks,
         ...optimizeDeps.esbuildOptions
       }
     },

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

@@ -63,13 +63,18 @@ const debug = createDebugger('vite:resolve-details', {
 
 export interface ResolveOptions {
   mainFields?: string[]
+  /**
+   * @deprecated In future, `mainFields` should be used instead.
+   * @default true
+   */
+  browserField?: boolean
   conditions?: string[]
   extensions?: string[]
   dedupe?: string[]
   preserveSymlinks?: boolean
 }
 
-export interface InternalResolveOptions extends ResolveOptions {
+export interface InternalResolveOptions extends Required<ResolveOptions> {
   root: string
   isBuild: boolean
   isProduction: boolean
@@ -85,7 +90,6 @@ export interface InternalResolveOptions extends ResolveOptions {
   tryPrefix?: string
   skipPackageJson?: boolean
   preferRelative?: boolean
-  preserveSymlinks?: boolean
   isRequire?: boolean
   // #3040
   // when the importer is a ts module,
@@ -238,6 +242,7 @@ export function resolvePlugin(resolveOptions: InternalResolveOptions): Plugin {
 
         if (
           targetWeb &&
+          options.browserField &&
           (res = tryResolveBrowserMapping(fsPath, importer, options, true))
         ) {
           return res
@@ -308,6 +313,7 @@ export function resolvePlugin(resolveOptions: InternalResolveOptions): Plugin {
 
         if (
           targetWeb &&
+          options.browserField &&
           (res = tryResolveBrowserMapping(
             id,
             importer,
@@ -451,7 +457,7 @@ function tryFsResolve(
     return res
   }
 
-  for (const ext of options.extensions || DEFAULT_EXTENSIONS) {
+  for (const ext of options.extensions) {
     if (
       postfix &&
       (res = tryResolveFile(
@@ -892,7 +898,11 @@ export function resolvePackageEntry(
     // This is because .mjs files can technically import .cjs files which would
     // make them invalid for pure ESM environments - so if other module/browser
     // fields are present, prioritize those instead.
-    if (targetWeb && (!entryPoint || entryPoint.endsWith('.mjs'))) {
+    if (
+      targetWeb &&
+      options.browserField &&
+      (!entryPoint || entryPoint.endsWith('.mjs'))
+    ) {
       // check browser field
       // https://github.com/defunctzombie/package-browser-field-spec
       const browserEntry =
@@ -903,6 +913,7 @@ export function resolvePackageEntry(
         // check if the package also has a "module" field.
         if (
           !options.isRequire &&
+          options.mainFields.includes('module') &&
           typeof data.module === 'string' &&
           data.module !== browserEntry
         ) {
@@ -933,7 +944,8 @@ export function resolvePackageEntry(
     }
 
     if (!entryPoint || entryPoint.endsWith('.mjs')) {
-      for (const field of options.mainFields || DEFAULT_MAIN_FIELDS) {
+      for (const field of options.mainFields) {
+        if (field === 'browser') continue // already checked above
         if (typeof data[field] === 'string') {
           entryPoint = data[field]
           break
@@ -951,16 +963,16 @@ export function resolvePackageEntry(
     for (let entry of entryPoints) {
       // make sure we don't get scripts when looking for sass
       if (
-        options.mainFields?.[0] === 'sass' &&
-        !options.extensions?.includes(path.extname(entry))
+        options.mainFields[0] === 'sass' &&
+        !options.extensions.includes(path.extname(entry))
       ) {
         entry = ''
         options.skipPackageJson = true
       }
 
       // resolve object browser field in package.json
       const { browser: browserField } = data
-      if (targetWeb && isObject(browserField)) {
+      if (targetWeb && options.browserField && isObject(browserField)) {
         entry = mapWithBrowserField(entry, browserField) || entry
       }
 
@@ -1001,7 +1013,7 @@ function resolveExports(
   if (!options.isRequire) {
     conditions.push('module')
   }
-  if (options.conditions) {
+  if (options.conditions.length > 0) {
     conditions.push(...options.conditions)
   }
 
@@ -1053,7 +1065,7 @@ function resolveDeepImport(
           `${path.join(dir, 'package.json')}.`
       )
     }
-  } else if (targetWeb && isObject(browserField)) {
+  } else if (targetWeb && options.browserField && isObject(browserField)) {
     // resolve without postfix (see #7098)
     const { file, postfix } = splitFileAndPostfix(relativeId)
     const mapped = mapWithBrowserField(file, browserField)

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

@@ -13,7 +13,7 @@ export function ssrRequireHookPlugin(config: ResolvedConfig): Plugin | null {
   if (
     config.command !== 'build' ||
     !config.build.ssr ||
-    !config.resolve.dedupe?.length ||
+    !config.resolve.dedupe.length ||
     config.ssr?.noExternal === true ||
     config.ssr?.format !== 'cjs' ||
     isBuildOutputEsm(config)

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

@@ -41,8 +41,8 @@ export interface ResolvedSSROptions extends SSROptions {
 
 export function resolveSSROptions(
   ssr: SSROptions | undefined,
-  buildSsrCjsExternalHeuristics?: boolean,
-  preserveSymlinks?: boolean
+  preserveSymlinks: boolean,
+  buildSsrCjsExternalHeuristics?: boolean
 ): ResolvedSSROptions {
   ssr ??= {}
   const optimizeDeps = ssr.optimizeDeps ?? {}

packages/vite/src/node/ssr/ssrExternal.ts

@@ -1,7 +1,7 @@
 import fs from 'node:fs'
 import path from 'node:path'
 import { createRequire } from 'node:module'
-import type { InternalResolveOptions } from '../plugins/resolve'
+import type { InternalResolveOptions, ResolveOptions } from '../plugins/resolve'
 import { tryNodeResolve } from '../plugins/resolve'
 import {
   bareImportRE,
@@ -53,7 +53,7 @@ export function cjsSsrResolveExternals(
 
   cjsSsrCollectExternals(
     config.root,
-    config.resolve.preserveSymlinks,
+    config.resolve,
     ssrExternals,
     seen,
     config.logger
@@ -116,8 +116,8 @@ export function createIsConfiguredAsSsrExternal(
     createFilter(undefined, noExternal, { resolve: false })
 
   const resolveOptions: InternalResolveOptions = {
+    ...config.resolve,
     root,
-    preserveSymlinks: config.resolve.preserveSymlinks,
     isProduction: false,
     isBuild: true
   }
@@ -211,7 +211,7 @@ function createIsSsrExternal(
 // is used reverting to the Vite 2.9 SSR externalization heuristics
 function cjsSsrCollectExternals(
   root: string,
-  preserveSymlinks: boolean | undefined,
+  resolveOptions: Required<ResolveOptions>,
   ssrExternals: Set<string>,
   seen: Set<string>,
   logger: Logger
@@ -227,9 +227,9 @@ function cjsSsrCollectExternals(
     ...rootPkg.dependencies
   }
 
-  const resolveOptions: InternalResolveOptions = {
+  const internalResolveOptions: InternalResolveOptions = {
+    ...resolveOptions,
     root,
-    preserveSymlinks,
     isProduction: false,
     isBuild: true
   }
@@ -247,7 +247,7 @@ function cjsSsrCollectExternals(
       esmEntry = tryNodeResolve(
         id,
         undefined,
-        resolveOptions,
+        internalResolveOptions,
         true, // we set `targetWeb` to `true` to get the ESM entry
         undefined,
         true
@@ -314,13 +314,7 @@ function cjsSsrCollectExternals(
   }
 
   for (const depRoot of depsToTrace) {
-    cjsSsrCollectExternals(
-      depRoot,
-      preserveSymlinks,
-      ssrExternals,
-      seen,
-      logger
-    )
+    cjsSsrCollectExternals(depRoot, resolveOptions, ssrExternals, seen, logger)
   }
 }
 

packages/vite/src/node/ssr/ssrModuleLoader.ts

@@ -118,13 +118,15 @@ async function instantiateModule(
   // CommonJS modules are preferred. We want to avoid ESM->ESM imports
   // whenever possible, because `hookNodeResolve` can't intercept them.
   const resolveOptions: InternalResolveOptions = {
-    dedupe,
+    mainFields: ['main'],
+    browserField: true,
+    conditions: [],
     extensions: ['.js', '.cjs', '.json'],
+    dedupe,
+    preserveSymlinks,
     isBuild: true,
     isProduction,
     isRequire: true,
-    mainFields: ['main'],
-    preserveSymlinks,
     root
   }