fix workaround for Safari 12.0.3

[kyrylodolynskyi]

Proposed changes

The issue is that when the element's getRect command is executed there is a Safari workaround to extract a rect from the browser executing js snippet. The workaround applied when one of the properties (x, y, width, or height) is a falsy (!) value, previously (in wdio 7) it was applied only if one of the properties were equal to null (== null). The problem happens when on appium you extract a region that has one of those properties 0, it is a valid value, but js snippet execution fails everything on appium.

Types of changes

I am replacing ! with === undefined.

• 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

I didn't find any tests in this area which is why I don't know how you guys usually test things like that. Feel free to add a test or instruct me on what I should add.

Reviewers: @webdriverio/project-committers

[christian-bromann]

Can we add a unit test for this?

[christian-bromann]

ping @kyryloonufriiev

[kyrylodolynskyi]

@christian-bromann sorry, I was away last week. I did add a unit test, how does it look now?

[christian-bromann]

LGTM 👍