NPM包自定义导出

exports 定义了自定义导出规则，可以理解为 路径映射

存在子路径时需要添加 exports 进行路径映射，并且 export 中的 . 配置会具有较高优先级，所以 . 对应的路径必须是真实存在的（此时，即使你在 main/module 中的路径写错了，也没关系）。

配置

假如我们为 package.json 做了如下配置，希望支持子路径

{
  "name": "@pyl/core-test",
  "exports": {
    ".": {
      "types": "./dist/index.d.ts",
      "import": "./dist/index.mjs",
      "require": "./dist/index.js"
    },
    "./util": {
      "types": "./dist/util.d.ts",
      "import": "./dist/util.mjs",
      "require": "./dist/util.js"
    }
  }
}

使用

import { Test } from '@pyl/core-test';
import { TestUtil } from '@pyl/core-test/util'; 
import '@pyl/core-test/dist/styles.css';

问题

• build 过程，无法识别 @pyl/core-test/dist/styles.css 路径

报错：

Module not found: Error: Package path ./dist/styles.css is not exported from package...

解决方案：

{
  "name": "@pyl/core-test",
  "exports": {
    ".": {
      "types": "./dist/index.d.ts",
      "import": "./dist/index.mjs",
      "require": "./dist/index.js"
    },
    "./util": {
      "types": "./dist/util.d.ts",
      "import": "./dist/util.mjs",
      "require": "./dist/util.js"
    },
    "./*": [ 
      "./*",
      "./*.d.ts"
    ]
  }
}

• ts 无法识别 @pyl/core-test/util 路径

报错：

TS2307: Cannot find module '@cbe/core-editor/backend' or its corresponding type declarations.

解决方案：

dist 目录下需要保证 util.d.ts 存在，并且需要和 exports 中子路径名称一致，否则依然无法找到路径

子路径对应的声明文件必须放到根目录，资源文件可以单独文件夹放置

{
  "name": "@pyl/core-test",
  "exports": {
    ".": {
      "types": "./dist/index.d.ts",
      "import": "./dist/index.mjs",
      "require": "./dist/index.js"
    },
    "./util": {
      "types": "./dist/util.d.ts",
      "import": "./dist/util.mjs",
      "require": "./dist/util.js"
    },
    "./*": [ 
      "./*",
      "./*.d.ts"
    ],
    "typesVersions": {
      "*": {
        "*": [
          "./dist/*",
          "./*"
        ]
      }
    }
  }
}