refactor: simplify build.transpile

lib/builder/webpack/base.js

@@ -142,14 +142,7 @@ export default class WebpackBaseConfig {
         exclude: file => {
           // not exclude files outside node_modules
           if (/node_modules/.test(file)) {
-            let transpile = this.options.build.transpile || []
-            // transpile supports string like 'vue-lib'
-            if (!Array.isArray(transpile)) {
-              transpile = [transpile]
-            }
-            // include SFCs in node_modules
-            transpile.push(/\.vue\.js/)
-            for (let pkg of transpile) {
+            for (let pkg of this.options.build.transpile) {
               // item in transpile can be string or regex object
               if (new RegExp(pkg).test(file)) {
                 return false

lib/common/options.js

@@ -187,5 +187,9 @@ Options.from = function (_options) {
   if (options.dev) {
     options.build.extractCSS = false
   }
+
+  // include SFCs in node_modules
+  options.build.transpile = [/\.vue\.js/].concat(options.build.transpile || [])
+
   return options
 }