// rollup.config.js
export default {
 // 核心选项
 input,   // 必须
 external,
 plugins,

 // 额外选项
 onwarn,

 // danger zone
 acorn,
 context,
 moduleContext,
 legacy

 output: { // 必须 (如果要输出多个，可以是一个数组)
  // 核心选项
  file,  // 必须
  format, // 必须
  name,
  globals,

  // 额外选项
  paths,
  banner,
  footer,
  intro,
  outro,
  sourcemap,
  sourcemapFile,
  interop,

  // 高危选项
  exports,
  amd,
  indent
  strict
 },
};

function createConfig(output, plugins = []) {
 const isProductionBuild =
  process.env.__DEV__ === 'false' || /\.prod\.js$/.test(output.file)
 const isGlobalBuild = /\.global(\.prod)?\.js$/.test(output.file)
 const isBunlderESMBuild = /\.esm\.js$/.test(output.file)
 const isBrowserESMBuild = /esm-browser(\.prod)?\.js$/.test(output.file)

 if (isGlobalBuild) {
  output.name = packageOptions.name
 }

 const shouldEmitDeclarations =
  process.env.TYPES != null &&
  process.env.NODE_ENV === 'production' &&
  !hasTSChecked

 const tsPlugin = ts({
  check: process.env.NODE_ENV === 'production' && !hasTSChecked,
  tsconfig: path.resolve(__dirname, 'tsconfig.json'),
  cacheRoot: path.resolve(__dirname, 'node_modules/.rts2_cache'),
  tsconfigOverride: {
   compilerOptions: {
    declaration: shouldEmitDeclarations,
    declarationMap: shouldEmitDeclarations
   },
   exclude: ['**/__tests__']
  }
 })
 // we only need to check TS and generate declarations once for each build.
 // it also seems to run into weird issues when checking multiple times
 // during a single build.
 hasTSChecked = true

 const externals = Object.keys(aliasOptions).filter(p => p !== '@vue/shared')

 output.sourcemap = true // 这句话是新增的
 return {
  input: resolve(`src/index.ts`),
  // Global and Browser ESM builds inlines everything so that they can be
  // used alone.
  external: isGlobalBuild || isBrowserESMBuild ? [] : externals,
  plugins: [
   json({
    namedExports: false
   }),
   tsPlugin,
   aliasPlugin,
   createReplacePlugin(
    isProductionBuild,
    isBunlderESMBuild,
    isGlobalBuild || isBrowserESMBuild
   ),
   ...plugins
  ],
  output,
  onwarn: (msg, warn) => {
   if (!/Circular/.test(msg)) {
    warn(msg)
   }
  }
 }
}