Do not give refs to stateless function components

[doomsower]

Some of my components are stateless functions, they accept style prop and pass it down to children. I want to style them with glamorous. However, I get annoying yellowbox warnings like this

Warning: Stateless function components cannot be given refs. Attempts to access this ref will fail.

Check the render method of `Icon`.
    in IconBase (created by Icon)
    in Icon (at PhotoPickerItem.js:51)

where IconBase is stateless function and Icon is glamorous(IconBase, { displayName: 'Icon' })(...). If I replace IconBase with class, those warning no longer appear.

So I added this simple condition. Glamorous component factory now checks if wrapped component is stateless function, and if so, it will not give it ref

I tries this with react-native 0.45.1, I did a quick search and I think this exactly warning message was introduced recently, so in older versions of react-native it might not be displayed or have different message.

[codecov-io]

Codecov Report

Merging #57 into master will increase coverage by 0.05%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master      #57      +/-   ##
==========================================
+ Coverage   92.02%   92.08%   +0.05%     
==========================================
  Files          10       10              
  Lines         138      139       +1     
  Branches       37       38       +1     
==========================================
+ Hits          127      128       +1     
  Misses          7        7              
  Partials        4        4

Impacted Files	Coverage Δ
src/create-glamorous.js	93.75% <100%> (+0.13%)	⬆️

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[hssrrw]

This is why I have to replace my functional components with classes. I wonder what takes it so long to merge the PR.

[kwelch]

Not sure, one thing that may help would be a test to show how it breaks and they this resolves that. Additionally, I would rebase while adding that test.

[atticoos]

Apologies for the holdup @hssrrw, this does appear to solve the problem, but would love to see some unit tests in place. I think we should be able to merge this up and follow up with some tests verifying this change.