zoro-cli/lib/plugins/config-webpack/template/script/config/lib.js

https://github.com/vuejs/vue-cli

const fs = require('fs')
const path = require('path')
const { error } = require('zoro-cli-util/logger')

module.exports = ({ api, options, pkg }) => {
  if (options.target !== 'lib') return

  api.chainWebpack(webpackConfig => {
    const { entry } = options
    const fullEntryPath = api.resolve(entry)

    // check entry existence
    if (!entry || !fs.existsSync(fullEntryPath)) {
      error(`找不到 entry: ${entry}`)
      process.exit(-1)
    }

    // config entry
    webpackConfig.entryPoints.clear()
    webpackConfig
      .entry(options.entryName || pkg.name)
      .add(fullEntryPath)
      .end()

    // user may override the libName by project.config.js -> libName
    const libName =
      options.libName ||
      pkg.libName ||
      path.basename(entry).replace(/\..*$/, '')

    webpackConfig.output.library(libName)

    // externalize Vue in case user imports it
    webpackConfig.externals({
      vue: {
        commonjs: 'vue',
        commonjs2: 'vue',
        root: 'Vue',
      },
    })
  })
}