Properly resolve polyfills in Vite 8

Author: davidmyersdev

src/globals.ts

@@ -0,0 +1,24 @@
+import {
+  type BooleanOrBuildTarget,
+  type BuildTarget,
+  isEnabled,
+} from './utils'
+
+export type GlobalName = typeof globals[number]
+
+export const globals = [
+  'buffer',
+  'global',
+  'process',
+] as const
+
+export const getGlobalsToHandle = (options: {
+  globals: { [Name in GlobalName]: BooleanOrBuildTarget },
+  target: BuildTarget,
+}): GlobalName[] => {
+  return globals.filter((global) => {
+    const value = options.globals[global]
+
+    return isEnabled(value, options.target)
+  })
+}

src/index.ts

@@ -4,6 +4,8 @@ import stdLibBrowser from 'node-stdlib-browser'
 import { handleCircularDependancyWarning } from 'node-stdlib-browser/helpers/rollup/plugin'
 import esbuildPlugin from 'node-stdlib-browser/helpers/esbuild/plugin'
 import type { Plugin } from 'vite'
+import { getModulesToPolyfill } from './modules'
+import { buildTrailingSlashNormalizer } from './plugins'
 import {
   type BooleanOrBuildTarget,
   type ModuleName,
@@ -136,6 +138,16 @@ export const nodePolyfills = (options: PolyfillOptions = {}): Plugin[] => {
     },
   }
 
+  const modulesToPolyfill = getModulesToPolyfill({
+    modulesToExclude: optionsResolved.exclude,
+    modulesToInclude: optionsResolved.include,
+  })
+
+  const trailingSlashNormalizer = buildTrailingSlashNormalizer({
+    modules: modulesToPolyfill,
+    protocolImports: optionsResolved.protocolImports,
+  })
+
   const isExcluded = (moduleName: ModuleName) => {
     if (optionsResolved.include.length > 0) {
       return !optionsResolved.include.some((includedName) => compareModuleNames(moduleName, includedName))
@@ -209,9 +221,11 @@ export const nodePolyfills = (options: PolyfillOptions = {}): Plugin[] => {
   const plugin: Plugin = {
     name: 'vite-plugin-node-polyfills',
     config(config, env) {
+      const isBuild = env.command === 'build'
       const isDev = env.command === 'serve'
       // @ts-expect-error - this.meta.rolldownVersion only exists with rolldown-vite 7+
       const isRolldownVite = !!this?.meta?.rolldownVersion
+      const isNativeInjectAvailable = isBuild && isRolldownVite
 
       // https://github.com/niksy/node-stdlib-browser/blob/3e7cd7f3d115ac5c4593b550e7d8c4a82a0d4ac4/README.md?plain=1#L203-L209
       const defines = {
@@ -227,7 +241,6 @@ export const nodePolyfills = (options: PolyfillOptions = {}): Plugin[] => {
         ...(isEnabled(optionsResolved.globals.process, 'build') ? { process: 'vite-plugin-node-polyfills/shims/process' } : {}),
       }
 
-      const isNativeInjectAvailable = env.command === 'build' && isRolldownVite
       rawInjectPlugin = (Object.keys(shimsToInject).length > 0 && !isNativeInjectAvailable) ? inject(shimsToInject) as Plugin : false
       if (rawInjectPlugin === false) {
         delete injectPlugin.transform
@@ -272,6 +285,7 @@ export const nodePolyfills = (options: PolyfillOptions = {}): Plugin[] => {
                     define: defines,
                   },
                   plugins: [
+                    trailingSlashNormalizer,
                     {
                       name: 'vite-plugin-node-polyfills:optimizer',
                       banner: isDev ? globalShimsBanner : undefined,
@@ -320,8 +334,10 @@ export const nodePolyfills = (options: PolyfillOptions = {}): Plugin[] => {
       }
     },
   }
+
   return [
+    trailingSlashNormalizer,
     injectPlugin,
     plugin,
-  ]
+  ].flat()
 }

src/modules.ts

@@ -0,0 +1,65 @@
+export type ModuleName = typeof modules[number]
+export type ModuleNameWithNodePrefix = `node:${ModuleName}`
+
+export const modules = [
+  '_stream_duplex',
+  '_stream_passthrough',
+  '_stream_readable',
+  '_stream_transform',
+  '_stream_writable',
+  'assert',
+  'buffer',
+  'child_process',
+  'cluster',
+  'console',
+  'constants',
+  'crypto',
+  'dgram',
+  'dns',
+  'domain',
+  'events',
+  'fs',
+  'http',
+  'http2',
+  'https',
+  'module',
+  'net',
+  'os',
+  'path',
+  'process',
+  'punycode',
+  'querystring',
+  'readline',
+  'repl',
+  'stream',
+  'string_decoder',
+  'sys',
+  'timers',
+  'timers/promises',
+  'tls',
+  'tty',
+  'url',
+  'util',
+  'vm',
+  'zlib',
+] as const
+
+export const getModulesToPolyfill = ({
+  modulesToExclude,
+  modulesToInclude,
+}: {
+  modulesToExclude: ModuleName[],
+  modulesToInclude: ModuleName[],
+}): ModuleName[] => {
+  return modules.filter((module) => {
+    if (modulesToInclude.length > 0) {
+      return modulesToInclude.includes(module)
+    }
+
+    return !modulesToExclude.includes(module)
+  })
+}
+
+export const isModuleName = (name: string): name is ModuleName => {
+  return modules.includes(name as ModuleName)
+}

src/plugins.ts

@@ -0,0 +1,55 @@
+import { type Plugin } from 'vite'
+import { globals } from './globals'
+import { type ModuleName } from './modules'
+import * as regex from './regex'
+
+export const buildTrailingSlashNormalizer = ({
+  modules,
+  protocolImports,
+}: {
+  modules: ModuleName[],
+  protocolImports: boolean,
+}): Plugin[] => {
+  const trailingSlashNormalizerRegex = regex.compose([
+    regex.any([
+      regex.join([
+        regex.when(
+          protocolImports,
+          regex.optional('node:'),
+        ),
+        regex.any(modules),
+      ]),
+      regex.join([
+        'vite-plugin-node-polyfills/shims/',
+        regex.any(globals),
+      ]),
+    ]),
+    '/',
+  ])
+
+  return [
+    {
+      // Vite v8.0.0+ does not support trailing slashes on package subpaths.
+      name: 'vite-plugin-node-polyfills:trailing-slash-normalizer',
+      enforce: 'pre',
+      resolveId: {
+        // @ts-expect-error This property is only supported in Vite v6.3.0+, so
+        // we must run the check inside the handler to maintain compatibility
+        // with older Vite versions.
+        filter: { id: trailingSlashNormalizerRegex },
+        async handler(source, importer, options) {
+          if (!trailingSlashNormalizerRegex.test(source)) {
+            return
+          }
+
+          const sourceWithoutTrailingSlash = source.replace(/\/$/, '')
+
+          return this.resolve(sourceWithoutTrailingSlash, importer, {
+            ...options,
+            skipSelf: true,
+          })
+        },
+      },
+    },
+  ]
+}

src/regex.ts

@@ -0,0 +1,29 @@
+export const any = (patterns: readonly string[]) => {
+  return group(patterns.join('|'))
+}
+
+export const compose = (patterns: readonly string[]) => {
+  const pattern = patterns.join('')
+
+  return new RegExp(`^${pattern}$`)
+}
+
+export const group = (pattern: string) => {
+  return `(?:${pattern})`
+}
+
+export const join = (patterns: readonly string[]) => {
+  return patterns.join('')
+}
+
+export const optional = (pattern: string) => {
+  return `${group(pattern)}?`
+}
+
+export const when = (condition: boolean, pattern: string, fallback = '') => {
+  if (condition) {
+    return pattern
+  }
+
+  return fallback
+}

src/utils.ts

@@ -1,4 +1,4 @@
-import type stdLibBrowser from 'node-stdlib-browser'
+import stdLibBrowser from 'node-stdlib-browser'
 import { type Plugin } from 'vite'
 
 export type BuildTarget = 'build' | 'dev'
@@ -33,6 +33,10 @@ export const isEnabled = (value: BooleanOrBuildTarget, target: BuildTarget) => {
   return value === target
 }
 
+export const isModuleName = (name: string): name is ModuleName => {
+  return name in stdLibBrowser
+}
+
 export const isNodeProtocolImport = (name: string) => {
   return name.startsWith('node:')
 }