Configure `@babel/runtime-corejs3` to exclude es.date.now

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I'm trying to prevent @babel/preset-env + @babel/plugin-transform-runtime + @babel/runtime-corejs3 from replacing Date.now(), in order to work around an issue preventing @sinonjs/fake-timers from working correctly.

According to the documentation for core-js, there should be a way to prevent it from applying the es.date.now polyfill, but I cannot figure out how to apply this configuration.

Example

index.js

import FakeTimers from '@sinonjs/fake-timers'

FakeTimers.install()

console.log(new Date().getTime())
console.log(Date.now())

Babel Transpile

$(npm bin)/babel index.js
...
console.log(new Date().getTime());
console.log((0, _now["default"])());

Note the last line of the traspilation output — I want it to be console.log(Date.now());

After reviewing the docs for @babel/preset-env, I feel like the exclude option is what I'm looking for, but I can't get it to work:

module.exports = {
  presets: [
    ['@babel/preset-env', { exclude: ['es.date.now'] }]
  ],
  plugins: [
    ['@babel/plugin-transform-runtime', { corejs: 3 }]
  ]
}

The above gives me an error:

> $(npm bin)/babel index.js
{ Invariant Violation: [BABEL] ./index.js: Invalid Option: The plugins/built-ins 'es.date.now' passed to the 'exclude' option are not
    valid. Please check data/[plugin-features|built-in-features].js in babel-preset-env (While processing: "./node_modules/@babel/preset-env/lib/index.js")
...

How do I configure Babel to exclude the es.date.now polyfill during traspilation?


Project Files

package.json

{
  "name": "test",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "author": "",
  "license": "ISC",
  "devDependencies": {
    "@babel/cli": "^7.8.4",
    "@babel/core": "^7.9.0",
    "@babel/plugin-transform-runtime": "^7.9.0",
    "@babel/preset-env": "^7.9.0",
    "@babel/register": "^7.9.0"
  },
  "dependencies": {
    "@babel/runtime": "^7.9.2",
    "@babel/runtime-corejs3": "^7.9.2",
    "@sinonjs/fake-timers": "^6.0.1"
  }
}

babel.config.js

module.exports = {
  presets: ['@babel/preset-env'],
  plugins: [
    ['@babel/plugin-transform-runtime', { corejs: 3 }]
  ]
}
1 Answers

See https://github.com/babel/babel/issues/10008. plugin-transform-runtime doesn't support browser targets. plugin-transform-runtime and preset-env can work independently.

So, to summarize. Currently it's not supporteed

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