ts-node 报错 ERR_UNKNOWN_FILE_EXTENSION

发生背景

项目里想用 ts-node 跑个脚本，执行：

$ npm install -g ts-node
$ ts-node ./scripts/html-gen.ts

代码是 TypeScript + ES Module （真香），于是 ts-node 开始抱怨：

TypeError [ERR_UNKNOWN_FILE_EXTENSION]: Unknown file extension ".ts" for ...\scripts\html-gen.ts
    at new NodeError (node:internal/errors:399:5)
    at Object.getFileProtocolModuleFormat [as file:] (node:internal/modules/esm/get_format:79:11)
    at defaultGetFormat (node:internal/modules/esm/get_format:121:38)
    at defaultLoad (node:internal/modules/esm/load:81:20)
    at nextLoad (node:internal/modules/esm/loader:163:28)
    at ESMLoader.load (node:internal/modules/esm/loader:605:26)
    at ESMLoader.moduleProvider (node:internal/modules/esm/loader:457:22)
    at new ModuleJob (node:internal/modules/esm/module_job:64:26)
    at ESMLoader.#createModuleJob (node:internal/modules/esm/loader:480:17)
    at ESMLoader.getModuleJob (node:internal/modules/esm/loader:434:34) {
  code: 'ERR_UNKNOWN_FILE_EXTENSION'
}

解决方案

在 tsconfig.json 中添加 "ts-node": { "esm": true } 即可。

@@ -4,5 +4,8 @@
     "outDir": "dist",
     "isolatedModules": true
   },
-  "include": ["src/**/*.ts", "components/**/*.vue", "scripts/*.ts"]
+  "include": ["src/**/*.ts", "components/**/*.vue", "scripts/*.ts"],
+  "ts-node": {
+    "esm": true
+  }
 }

（如果还报错，请参考这篇文章）

发生原因

ts-node 默认将文件视为 CommonJS ，需要显式声明为 ES Module 。（个人理解）

参考资料

• Troubleshooting | ts-node