Add support for textDecorationLine property

[davixyz]

Hi, this adds support for the textDecorationLine property for text.
Tested on Sketch 44.1
Example of usage:

<Text  style={{textDecorationLine: 'underline'}}>
  Hello World
</Text>

which outputs this:

The API supports the following attributes: none, underline, line-through, double.

I have some questions though:

• Should I create some tests around this?
• How about the documentation, does this grant an update?
• There was an autoformat on commit, I didn't make some of those changes. is that okay?

[jemgold]

Wooo, great work @davidseik :)

• we haven't found a good solution for tests right now, unfortunately. we're hoping that relying on small functions & flow keeps this mostly error free, but we just test in examples/ 😱
• Yes! we can add the textDecoration* props to the Styling documentation :)
• That's fine! Prettier is set up to automatically format files; presumably that file just hadn't been touched since we added it :)

Will dig in this afternon

[jemgold]

Looks great, other than the one property name I flagged.

(btw I'm on vacation next week - feel free to ping other maintainers to get this merged if I miss it)

[jemgold]

we mirror the React Native APIs as much as possible — can you change this to textDecorationLine to match?

[davixyz]

Hi Jon, I actually wanted to use the exact same API of textDecorationLine but I found this:
https://github.com/airbnb/react-sketchapp/blob/master/src/stylesheet/expandStyle.js#L61

When the style gets passed down as a textStyle this part expands it to be renamed textDecoration; I don't know why this is needed. I can go ahead and remove the shortHand here and add the textDecorationLine over here so it's propagated like it. Thoughts?

[jemgold]

🙃 I think maybe it was actually correct the first time - looks like I have your original commit and it's indeed working properly by expanding the textDecorationLine into textDecoration. Not sure what went wrong the first time I reviewed it, sorry!

Documentation update looks good - we want the public interface to be textDecorationLine.

[davixyz]

Got it, then let me change it back.

[davixyz]

Funny thing is that because of the expansion they both work textDecoration & textDecorationLine; Thoughts?

[davixyz]

@lelandrichardson @BenjaminCorey can you guys check if this can be merged?