Replace OR with AND operator

[tintin1343]

Changed the operators in flexboxIE.js and flexboxOld.js

The issue with the 'OR' operator is that it will create issues in pages which does not have a display property.

Changing the OR operator with AND will do the work.

Closes #70

[tintin1343]

@rofrischmann : I do not understand the reason for the tests failure. Could you guide me ?

[robinweser]

@tintin1343 Heyhey, just check out the issue again :) I ve posted something about it.
To validate my fix you could add this to the tests:

Current tests

describe('Prefixing display', () => {
  it('should not remove display property', () => {
    expect(new Prefixer({ userAgent: MSIE10 }).prefix({
      display: 'block'
    })).to.eql({ display: 'block' })
  })
})

New tests

describe('Prefixing display', () => {
  it('should not remove display property', () => {
    expect(new Prefixer({ userAgent: MSIE10 }).prefix({
      display: 'block'
    })).to.eql({ display: 'block' })
  })
  it('should not throw if display is null or undefined', () => {
    expect(new Prefixer({ userAgent: Chrome45 }).prefix({
      display: null
    })).to.eql({ display: null })
    expect(new Prefixer({ userAgent: Chrome45 }).prefix({
      display: undefined
    })).to.eql({ display: undefined })
  })
})

[tintin1343]

@rofrischmann : Ok. I saw your comment on the issue. Let me make the necessary changes and edit my pull request.

[robinweser]

Alright thanks a lot! Tests seem to pass now :P The only reason for the failed status is actually an issue with codeclimate which I am not sure how to fix right now.

[tintin1343]

@rofrischmann : Cool. I was wondering why that was happening when my npm test passed. You are welcome.

[necolas]

Does the prefix-all package also need part of this patch?

[robinweser]

@necolas Actually it should work for your usecase as far as I know you do not have null or undefined values right? Still I will add this right away.

[robinweser]

@necolas https://github.com/rofrischmann/inline-style-prefix-all/releases/tag/1.0.2 here we go. I actually could remove this display check at all as we already use the full flex plugin :P