refactor(webpack): simplify transpile normalization (#6179)

packages/webpack/src/config/base.js

@@ -22,7 +22,6 @@ export default class WebpackBaseConfig {
   constructor (builder) {
     this.builder = builder
     this.buildContext = builder.buildContext
-    this.modulesToTranspile = this.normalizeTranspile()
   }
 
   get colors () {
@@ -55,21 +54,29 @@ export default class WebpackBaseConfig {
     return this.buildContext.buildOptions.loaders
   }
 
-  normalizeTranspile () {
-    // include SFCs in node_modules
-    const items = [/\.vue\.js/i]
+  get modulesToTranspile () {
+    return [
+      /\.vue\.js/i, // include SFCs in node_modules
+      ...this.normalizeTranspile({ pathNormalize: true })
+    ]
+  }
+
+  normalizeTranspile ({ pathNormalize = false } = {}) {
+    const transpile = []
     for (let pattern of this.buildContext.buildOptions.transpile) {
       if (typeof pattern === 'function') {
         pattern = pattern(this.nuxtEnv)
       }
       if (pattern instanceof RegExp) {
-        items.push(pattern)
+        transpile.push(pattern)
       } else if (typeof pattern === 'string') {
         const posixModule = pattern.replace(/\\/g, '/')
-        items.push(new RegExp(escapeRegExp(path.normalize(posixModule))))
+        transpile.push(new RegExp(escapeRegExp(
+          pathNormalize ? path.normalize(posixModule) : posixModule
+        )))
       }
     }
-    return items
+    return transpile
   }
 
   getBabelOptions () {

packages/webpack/src/config/server.js

@@ -1,7 +1,6 @@
 import path from 'path'
 import fs from 'fs'
 import webpack from 'webpack'
-import escapeRegExp from 'lodash/escapeRegExp'
 import nodeExternals from 'webpack-node-externals'
 
 import VueSSRServerPlugin from '../plugins/vue/server'
@@ -13,32 +12,19 @@ export default class WebpackServerConfig extends WebpackBaseConfig {
     super(...args)
     this.name = 'server'
     this.isServer = true
-    this.whitelist = this.normalizeWhitelist()
-  }
-
-  normalizeWhitelist () {
-    const whitelist = [
-      /\.(?!js(x|on)?$)/i
-    ]
-    for (let pattern of this.buildContext.buildOptions.transpile) {
-      if (typeof pattern === 'function') {
-        pattern = pattern(this.nuxtEnv)
-      }
-      if (pattern instanceof RegExp) {
-        whitelist.push(pattern)
-      } else if (typeof pattern === 'string') {
-        const posixModule = pattern.replace(/\\/g, '/')
-        whitelist.push(new RegExp(escapeRegExp(posixModule)))
-      }
-    }
-
-    return whitelist
   }
 
   get devtool () {
     return 'cheap-module-source-map'
   }
 
+  get externalsWhitelist () {
+    return [
+      /\.(?!js(x|on)?$)/i,
+      ...this.normalizeTranspile()
+    ]
+  }
+
   env () {
     return Object.assign(super.env(), {
       'process.env.VUE_ENV': JSON.stringify('server'),
@@ -117,7 +103,7 @@ export default class WebpackServerConfig extends WebpackBaseConfig {
         if (fs.existsSync(dir)) {
           config.externals.push(
             nodeExternals({
-              whitelist: this.whitelist,
+              whitelist: this.externalsWhitelist,
               modulesDir: dir
             })
           )