Invalid value "umd" for option "output.format" - UMD and IIFE output formats are not supported for code-splitting builds.问题修复

问题：vite2打lib库包时报Invalid value "umd" for option "output.format" - UMD and IIFE output formats are not supported for code-splitting builds.错误

原因：lib.formats默认 ['es', 'umd']，output.format默认es，不支持多个值

解决方案：lib.formats设置为['es']

vite.config.js配置的build如下：

import { defineConfig } from 'vite';
import { createVuePlugin } from 'vite-plugin-vue2';
const path = require('path');

export default defineConfig({
  build: {
    // 输出文件目录
    outDir: 'libs',
    // 生产环境移除console
    minify: 'terser',
    lib: {
      entry: path.resolve(__dirname, './src/components/index.ts'),
      name: 'libs',
      fileName: (format) => `isafety-ui.${format}.js`,
      formats: ['es'], // 默认['es', 'umd']
    },
    terserOptions: {
      compress: {
        drop_console: true,
        drop_debugger: true,
      },
    },
    rollupOptions: {
      // 确保外部化处理那些你不想打包进库的依赖
      external: ['vue'],
      output: {
        // 在 UMD 构建模式下为这些外部化的依赖提供一个全局变量
        globals: {
          vue: 'Vue',
        },
        // format: 'es', // 默认'es'
      }
    }
  },
});