Production build breaks browsers which doesn't support PropertyShorthend

[pudek357]

Hi everyone 👋

This PR introduced problem with production build, when we use in code PropertyShorthend.

I was trying to investigate this problem and I figured out that the problem is with this line.
If ecma is set to >= 6 then UglifyJS produces for example code:

const someVar = 'abc';
const testObj = {
  someVar,
};

that production build:

const testObj = {  someVar };

but should instead:

const testObj = {  someVar: someVar  };

[gauravtiwari]

@pudek357 You could tweak your babelrc with appropriate browser query: http://browserl.ist/?q=%3E%3D+1%25 (this is what we ship with atm)

You could set specific browsers you need to support in your query: https://github.com/ai/browserslist#queries

[pudek357]

it's mine .babelrc:

{
  "presets": [
    [
      "env",
      {
        "modules": false,
        "targets": {
          "browsers": [
            "last 2 versions",
            "> 1%",
            "ie > 10"
          ],
          "uglify": true
        },
        "useBuiltIns": true
      }
    ],
    "react"
  ],
  "plugins": [
    "syntax-dynamic-import",
    "transform-object-rest-spread",
    [
      "transform-class-properties",
      {
        "spec": true
      }
    ]
  ]
}

It's work with "@rails/webpacker": "3.2.0" when i change version to 3.2.1 then it doesn't uglify properly PropertyShorthend.

Additionally when you change here ecma value to 5 then it will work good, so I think problem is with UglifyJs with was added in 3.2.1

[gauravtiwari]

Please try the latest RC, otherwise feel free to open a new issue with more details.