Adding exception handling for invalid parse data.

[lorenzwalthert]

This closes #137.

For style_text()

library("styler")
style_text("a 3")
#> Error in parsing the supplied text. Here is the parsing error message: 
#> Error in parse(text = text, keep.source = TRUE): <text>:1:3: unexpected numeric constant
#> 1: a 3
#>       ^
```And for `style_file()` and friends.
```r
path <- tempfile(fileext = ".R")
writeLines("a 3", path)
style_file(path)
#> Error in parsing file /private/var/folders/8l/fhmv3yj12kncddcjqwc19tkr0000gr/T/RtmpSOgZBl/file728e3c9f60a9.R Here is the parsing error message: 
#> Error in parse(text = text, keep.source = TRUE): <text>:1:3: unexpected numeric constant
#> 1: a 3
#>       ^
#> --------------------------------------------------------------------------------

As you can see from the source code, it will still style all parsable files if there are any.

That's how it looks now. Much better I think.

[lorenzwalthert]

The only thing that bothers me a bit is that the return value is just a message, not an error, but I think there is no way around it if we want to continue with other files, right?

[codecov]

Codecov Report

Merging #139 into master will increase coverage by 0.15%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master     #139      +/-   ##
==========================================
+ Coverage   87.46%   87.61%   +0.15%     
==========================================
  Files          19       19              
  Lines         742      751       +9     
==========================================
+ Hits          649      658       +9     
  Misses         93       93

Impacted Files	Coverage Δ
R/ws.R	88.88% <100%> (+5.55%)	⬆️
R/transform.R	97.36% <100%> (ø)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update c9339ba...62fd6b7. Read the comment docs.

[krlmlr]

I'm not sure we need a new argument here. Rather the behavior should always be reasonable if parsing fails. If necessary, we could change transform_lines_enc() to account for this.

[lorenzwalthert]

Ok, so we can remove the argument then. I am not sure whether it makes sense to implement the error handling in transform_lines_enc() since it has already a error handling but I don't know why it does only give a warning instead of an error.

library("styler")
style_text("a 3")
#> Error in parse(text = text, keep.source = TRUE): <text>:1:3: unexpected numeric constant
#> 1: a 3
#>       ^
path <- tempfile(fileext = ".R")
writeLines("a 3", path)
style_file(path)
#> Warning: When processing file6b1f0f56be.R: <text>:1:3: unexpected numeric constant
#> 1: a 3
#>       ^
#> Error in if (any(changed)) {: missing value where TRUE/FALSE needed
style_dir(dirname(path))
#> Warning: When processing ./file6b1f0f56be.R: <text>:1:3: unexpected numeric constant
#> 1: a 3
#>       ^
#> Error in if (any(changed)) {: missing value where TRUE/FALSE needed

[krlmlr]

I forgot how transform_lines_enc() works, the error handling seems sufficient already. Do you need any(changed, na.rm = TRUE) ?

[lorenzwalthert]

Yes, with any(changed, na.rm = TRUE), we only get the first warning message. So I will undo my error handling implementation and adapt the tests.

[lorenzwalthert]

In my eyes, there is one more tweak necessary in the utf8 package. Unfortunately, it is not visible in the reprex above because reprex strangely does not show all warnings I get in the console. I opened #15 and submitted a PR.

[lorenzwalthert]

Also, do you need to submit utf8 to CRAN in order to submit styler to CRAN, right?

[krlmlr]

Yes, I'm about to submit utf8.

[lorenzwalthert]

Ok, I now reverted everything but kept the tests, so error handling is now done by utf8.

[krlmlr]

Awesome, thanks!