Exception Handling

[lorenzwalthert]

When working on #58, I tried this

styler::style_text("call(x), { } ")
#> Error in parse(text = text, keep.source = TRUE): <text>:1:8: unexpected ','
#> 1: call(x),
#>            ^

This is not particuarly useful but one can guess the root of the problem. If you want to style a file that contains such an invalid expression, you get

style_dir("tests/testthat/public-api/xyzdir/subdir/")
Error in if (!any(ret)) { : missing value where TRUE/FALSE needed
In addition: Warning message:
 Show Traceback
 ...

How should we handle these cases? I don't have experience in error handling in packages so @krlmlr can you advise? Should we implement before submitting to CRAN? Also related to assertive tests etc.

[krlmlr]

Can we wrap a tryCatch() around the parse() call?

[lorenzwalthert]

Yes, but I think that's not very informative if you don't know which file is the problem. Maybe we add an argument assert_code to transform_files() and if set, we try parsing before executing the styling and return an informative error message if parsing fails for one of the files.