fix: handle webpack errors as described in https://webpack.js.org/api…

…/node/\#error-handling

cli/src/lib/plugin/build.js

@@ -13,7 +13,7 @@ module.exports = async ({ paths }) => {
  const webpackConfig = webpackConfigFactory({ env: 'production', paths })
  const compiler = webpack(webpackConfig)
  return new Promise((resolve, reject) => {
- compiler.run(err => {
+ compiler.run((err, stats) => {
  if (err) {
  if (!err.message) {
  reject(err)
@@ -32,6 +32,23 @@ module.exports = async ({ paths }) => {
  return
  }
 
+ const info = stats.toJson()
+
+ if (stats.hasErrors()) {
+ reject(
+ new Error(
+ info.errors.map(error => error.message).join('\n')
+ )
+ )
+ return
+ }
+
+ if (stats.hasWarnings()) {
+ console.warn(info.warnings)
+ reject(new Error(info.warnings))
+ return
+ }
+
  resolve()
  })
  })