fix: polyfill injection when building app on multiple threads (#5592)

Author: dtcz

packages/@vue/cli-service/__tests__/Service.spec.js

@@ -318,6 +318,8 @@ test('api: configureWebpack preserve ruleNames', () => {
 })
 
 test('internal: should correctly set VUE_CLI_ENTRY_FILES', () => {
+  delete process.env.VUE_CLI_ENTRY_FILES
+
   const service = createMockService([{
     id: 'test',
     apply: api => {

packages/@vue/cli-service/lib/Service.js

@@ -279,7 +279,10 @@ module.exports = class Service {
       )
     }
 
-    if (typeof config.entry !== 'function') {
+    if (
+      !process.env.VUE_CLI_ENTRY_FILES &&
+      typeof config.entry !== 'function'
+    ) {
       let entryFiles
       if (typeof config.entry === 'string') {
         entryFiles = [config.entry]

packages/@vue/cli-service/lib/commands/build/resolveAppConfig.js

@@ -1,4 +1,11 @@
 module.exports = (api, args, options) => {
+  // respect inline entry
+  if (args.entry && !options.pages) {
+    api.configureWebpack(config => {
+      config.entry = { app: api.resolve(args.entry) }
+    })
+  }
+
   const config = api.resolveChainableWebpackConfig()
   const targetDir = api.resolve(args.dest || options.outputDir)
 
@@ -36,14 +43,5 @@ module.exports = (api, args, options) => {
     }
   }
 
-  const rawConfig = api.resolveWebpackConfig(config)
-
-  // respect inline entry
-  if (args.entry && !options.pages) {
-    const entry = api.resolve(args.entry)
-    rawConfig.entry = { app: entry }
-    process.env.VUE_CLI_ENTRY_FILES = JSON.stringify([entry])
-  }
-
-  return rawConfig
+  return api.resolveWebpackConfig(config)
 }