量角器导出错误-使用另一个项目中的类

Question

我试图将我的项目分成两个单独的项目，然后在它们之间重用文件。

在运行时出现以下错误SyntaxError: Unexpected token export-export {Helper} from './src/xx/hepler’;

---

主项目

使用辅助类的类。

import { Helper } from ‘sub-project’;
// const Helper = require (‘sub-project’);  also tried this 

package.json

"devDependencies": {
    "sub-project": "file:../../sub-project/e2e"
}

---

子项目

app.ts

 export {Helper} from './src/xx/helper’;

helper.ts

export class Helper {

}

package.json

 "name": "sub-project",

 "main": "app.ts"

tsconfig.json

{
    "extends": "../tsconfig.json",
    "compilerOptions": {
        "outDir": "lib",
        "rootDir": ".",
        "target": "es5",
        "module": "commonjs",
        "types": [
        ],
    }
}