webpack从2升级到3后出错

Question

我已将webpack从2.5.1升级到3.6。在webpack开发服务器模式下一切顺利但在webpack构建中失败。我观察到以下错误。

ERROR in chunk main [entry] [name].[chunkhash].js 'import' and 'export' may only appear at the top level (42:6) | if (false) { | module.hot.accept('./reducers', function () { | import('./reducers').then(function (reducerModule) { | var createReducers = reducerModule.default; | var nextReducers = createReducers(store.asyncReducers);

以下是升级的软件包。

什么会触发错误？我已经正确设置了babel loader，它可以在2.5 webpack版本中正常工作。

更新：如果我删除new webpack.optimize.ModuleConcatenationPlugin()我没有收到该错误。看起来像块文件有es6代码，而babel-parser没有解析。我如何配置webpack以使其工作？

Answer 1

您可以导入顶级

import reducers from './reducers'

if (false) {
  module.hot.accept('./reducers', function () {
    reducers.then(function (reducerModule) {
      var createReducers = reducerModule.default;
      var nextReducers = createReducers(store.asyncReducers);

或

if (false) {
  module.hot.accept('./reducers', function () {
    require('./reducers').default.then(function (reducerModule) {
      var createReducers = reducerModule.default;
      var nextReducers = createReducers(store.asyncReducers);