ASA journal style

[hadley]

This looks good from my end. What else do you need for rticles?

[jjallaire]

Could you add a test here (https://github.com/rstudio/rticles/blob/master/tests/testthat/test_formats.R#L42) once this is ready to go. I usually like to run these tests on all platforms before merging b/c the distinct LaTeX environments can easily create incompatibilities.

[hadley]

I refactored test_format() — it didn't work with asa_article because output_file was a full path, rather than a file name. I couldn't quite figure out what you were trying to do, but I think I've captured the intent and simplified the code a little (and all the tests pass for me)

[hadley]

(I also alphabetised the test formats so it's more obvious where you should add your test)

[jjallaire]

Looks good, thanks!