Various code / tests updates

[olivroy]

These are just (mostly) cosmetic changes that I made while browsing styler source code.

[codecov-commenter]

Codecov Report

Merging #1122 (28c2f14) into main (fdb7580) will increase coverage by 0.02%. The diff coverage is 45.45%.

:exclamation: Current head 28c2f14 differs from pull request most recent head 28b5d06. Consider uploading reports for the commit 28b5d06 to get more accurate results

@@            Coverage Diff             @@
##             main    #1122      +/-   ##
==========================================
+ Coverage   92.16%   92.18%   +0.02%     
==========================================
  Files          46       46              
  Lines        2654     2650       -4     
==========================================
- Hits         2446     2443       -3     
+ Misses        208      207       -1     

Impacted Files	Coverage Δ
R/communicate.R	100.00% <ø> (+5.55%)	:arrow_up:
R/parse.R	87.65% <0.00%> (ø)
R/set-assert-args.R	90.47% <0.00%> (ø)
R/testing.R	66.66% <0.00%> (ø)
R/transform-code.R	95.08% <0.00%> (ø)
R/vertical.R	60.00% <0.00%> (ø)
R/nested-to-tree.R	92.85% <100.00%> (ø)
R/transform-files.R	97.45% <100.00%> (-0.04%)	:arrow_down:

[github-actions[bot]]

This is how benchmark results would change (along with a 95% confidence interval in relative change) if fdb7580cd605dec69aa8ee797780b3c909f622f7 is merged into main:

•   :ballot_box_with_check:cache_applying: 167ms -> 166ms [-1.88%, +1.69%]
•   :ballot_box_with_check:cache_recording: 616ms -> 615ms [-0.49%, +0.17%]
•   :ballot_box_with_check:without_cache: 1.19s -> 1.19s [-0.49%, +0.32%]

Further explanation regarding interpretation and methodology can be found in the documentation.

[lorenzwalthert]

Great, thanks for the contribution 🥳