objectSpread2 failure

[XhmikosR]

Bug Report

Current Behavior

While trying to update babel and its plugins to the latest v7.5.4 version, we still get some failures in our test suite https://travis-ci.org/twbs/bootstrap/jobs/556685620#L788

The related code should be https://github.com/twbs/bootstrap/blob/master/js/src/dom/manipulator.js#L47

Going back to v7.4.x and objectSpread works as expected.

Input Code

• https://github.com/twbs/bootstrap

Babel Configuration (.babelrc, package.json, cli command)

module.exports = {
  presets: [
    [
      '@babel/env',
      {
        loose: true,
        modules: false,
        exclude: ['transform-typeof-symbol']
      }
    ]
  ],
  plugins: [
    '@babel/plugin-proposal-object-rest-spread'
  ],
  env: {
    test: {
      plugins: [ 'istanbul' ]
    }
  }
};

Environment

• Babel version(s): v7.5.4
• Node/npm version: Node 10.16.0/npm 6.9.0
• OS: Windows 10
• Monorepo: no
• How you are using Babel: cli

[babel-bot]

Hey @XhmikosR! We really appreciate you taking the time to report an issue. The collaborators
on this project attempt to help as many people as possible, but we're a limited number of volunteers,
so it's possible this won't be addressed swiftly.

If you need any help, or just have general Babel or JavaScript questions, we have a vibrant Slack
community that typically always has someone willing to help. You can sign-up here
for an invite.

[JLHwung]

The unit test fails after Object.getOwnPropertyDescriptor is stub to return false.

Since 7.5.0, the objectSpread will call Object.getOwnPropertyDescriptor under the hood to filter enumerable properties. However, since most of time a DOMStringMap would not include a symbol key and Object.keys() always return enumerable string properties, objectSpread should not invoke Object.getOwnPropertyDescriptor.

Though it seems quite irrelevant on the surface. This issue would be fixed by #10189.

A workaround will be to remove the stub and wait until #10189 is released. After it is released it should be okay to keep the stub.

[nicolo-ribaudo]

Note: while I'm happy that this issue has been fixed for your use case, unfortunately Babel can't guarantee that it works (or will work) when built-in functions have been modified in a nonstandard way.

[Johann-S]

Thanks @JLHwung it was because of our unit tests nothings related to Babel here 👍