Make React development mode an option

[arv]

transform('<a/>', {transforms: ['jsx']});

generates code that has __self and __source props. This is normally only enabled when you use preset-react with development to true.

[alangpierce]

Heh, I had a feeling someone would request this. I've been trying to keep this project zero/low-configuration and focused on the "fast development builds" use case, but I suppose it's reasonable that people would want the same code running in dev and prod. FWIW, my use case at work is to only use it in development and still use Babel and tsc for prod builds, since we still want to support IE. Production builds are also already slower, and they run in CI anyway, so the speed gains from Sucrase are unimportant there.

Do you have thoughts on the right config here? Currently I'm thinking there can be a new production?: boolean in the options, which will exclude __self and __source. In the future, if some other transform wants to behave differently in dev and prod, it can use that flag. If there's a real use case for configuring the transforms individually, then that can be done with new options, but I'd prefer to keep the config small.

Happy to accept a PR (using the production flag above), or I can try implementing it when I get a chance.

[arv]

I have this working already. I wanted to send the other more straight forward PR first to get a better hang of the process in this project.

[alangpierce]

Fixed with #270.