Proposed changes

When I tried element.isEqual() on IE11, webdriver returned an error because IE11 does not support the arrow function syntax.

I tried this code https://gist.github.com/FujiHaruka/e74fd83edb1a273c61ed8b82b94b798c on BrowserStack and got error logs like below.

INFO webdriver: [POST] http://hub.browserstack.com/wd/hub/session/xxxxxxx/execute/sync
INFO webdriver: DATA {
  script: 'return ((el1, el2) => el1 === el2).apply(null, arguments)',
  args: [
    {
      'element-6066-11e4-a52e-4f735466cecf': 'bf323ba6-f2ba-4cf3-a4d0-1e0fca13fedf',
      ELEMENT: 'bf323ba6-f2ba-4cf3-a4d0-1e0fca13fedf'
    },
    {
      'element-6066-11e4-a52e-4f735466cecf': 'bf323ba6-f2ba-4cf3-a4d0-1e0fca13fedf',
      ELEMENT: 'bf323ba6-f2ba-4cf3-a4d0-1e0fca13fedf'
    }
  ]
}
ERROR webdriver: Request failed with status 500 due to javascript error: Error executing JavaScript

I'm not sure whether WebdriverIO supports IE11 or not, but it would be nice if we can run WebdriverIO on IE11 with less efforts. So my humble suggestion is using a plain function instead of an arrow function in isEqual.js. I confirmed that my code above works fine with this change.

Types of changes

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update

Checklist

• I have read the CONTRIBUTING doc
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)
• I have added proper type definitions for new commands (if appropriate)

Further comments

Reviewers: @webdriverio/project-committers