Incorrect name of async function after build.

[zhengxiaoyao0716]

Is this a bug report?

Yes

Did you try recovering your dependencies?

I generated a new project to test it.

Environment

While, the command create-react-app --info seems not work...
(paste the output of the command here)

So let me paste my package.json instead (just create a new project use npx create-react-app):

{
  "name": "test",
  "version": "0.1.0",
  "private": true,
  "dependencies": {
    "react": "^16.6.0",
    "react-dom": "^16.6.0",
    "react-scripts": "2.1.1"
  },
  "scripts": {
    "start": "react-scripts start",
    "build": "react-scripts build",
    "test": "react-scripts test",
    "eject": "react-scripts eject"
  },
  "eslintConfig": {
    "extends": "react-app"
  },
  "browserslist": [
    ">0.2%",
    "not dead",
    "not ie <= 11",
    "not op_mini all"
  ]
}

Steps to Reproduce

1. remove all the useless asset, we only need an index.js to reproduce it.
2. paste those code into index.js:

const test = {
    fn0: () => { },
    fn1: function () { },
    fn2() { },

    fn3: async () => { },
    fn4: async function () { },
    async fn5() { },

    fn6: () => Promise.resolve(),
};
console.log(Object.entries(test).map(([key, func]) => ({ key, name: func.name, func })));

3. Now start the project, at the development environment (npm run start), what the browser terminal print:
   
   seems all right.
4. However, if we start the project with production mode (npm run build), the problem appeared:
   

---

Maybe this problem is a bug of webpack, but due to the create-react-app not allow us to build the project in development mode, or build without minify, I found hard to further locate the problem .

[zhengxiaoyao0716]

The problem also happend with static function of class, neither async or normal:

class Test {
    static fn() {}
}
console.log(Test.fn.name);

It always print value.

[zhengxiaoyao0716]

I found that after build it would generate some codes like {fn:function(){},async:function(){function t(){};return t}()} , so maybe the closure caused this problem.

[jakepoz]

We are seeing something similar, dev builds work fine, but production builds fail on Firefox, our promise catch is never being called.

[stale]

This issue has been automatically marked as stale because it has not had any recent activity. It will be closed in 5 days if no further activity occurs.

[stale]

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