子路径的导出

当使用 "exports" 字段时，可以通过将主入口点视为 "." 子路径来定义自定义子路径以及主入口点：

{
  "main": "./main.js",
  "exports": {
    ".": "./main.js",
    "./submodule": "./src/submodule.js"
  }
}

现在消费者只能导入 "exports" 中定义的子路径：

import submodule from 'es-module-package/submodule';
// 加载 ./node_modules/es-module-package/src/submodule.js

而其他子路径会出错：

import submodule from 'es-module-package/private-module.js';
// 抛出 ERR_PACKAGE_PATH_NOT_EXPORTED

When using the "exports" field, custom subpaths can be defined along with the main entry point by treating the main entry point as the "." subpath:

{
  "main": "./main.js",
  "exports": {
    ".": "./main.js",
    "./submodule": "./src/submodule.js"
  }
}

Now only the defined subpath in "exports" can be imported by a consumer:

import submodule from 'es-module-package/submodule';
// Loads ./node_modules/es-module-package/src/submodule.js

While other subpaths will error:

import submodule from 'es-module-package/private-module.js';
// Throws ERR_PACKAGE_PATH_NOT_EXPORTED