fix and test .onLoad()

[lorenzwalthert]

Closes #893.

[github-actions]

This is how benchmark results would change (along with a 95% confidence interval in relative change) if 85d5b15 is merged into main:

•   :ballot_box_with_check:cache_applying: 30.8ms -> 30.4ms [-2.24%, +0.09%]
•   :ballot_box_with_check:cache_recording: 1.07s -> 1.08s [-0.26%, +1%]
•   :ballot_box_with_check:without_cache: 2.86s -> 2.87s [-0.29%, +1.19%]

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

[codecov-commenter]

Codecov Report

Merging #894 (6a29ecf) into main (1744cb3) will increase coverage by 0.64%.
The diff coverage is 95.65%.

@@            Coverage Diff             @@
##             main     #894      +/-   ##
==========================================
+ Coverage   89.65%   90.30%   +0.64%     
==========================================
  Files          47       47              
  Lines        2514     2537      +23     
==========================================
+ Hits         2254     2291      +37     
+ Misses        260      246      -14     

Impacted Files	Coverage Δ
R/relevel.R	46.37% <60.00%> (+0.22%)	⬆️
R/detect-alignment-utils.R	90.90% <100.00%> (+0.28%)	⬆️
R/roxygen-examples.R	98.43% <100.00%> (+0.05%)	⬆️
R/rules-tokens.R	100.00% <100.00%> (ø)
R/token-create.R	96.07% <100.00%> (+0.16%)	⬆️
R/transform-files.R	97.05% <100.00%> (+0.04%)	⬆️
R/zzz.R	39.53% <100.00%> (+39.53%)	⬆️

---

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[github-actions]

This is how benchmark results would change (along with a 95% confidence interval in relative change) if 0813ed3 is merged into main:

•   :ballot_box_with_check:cache_applying: 30.5ms -> 30.6ms [-0.8%, +0.93%]
•   :ballot_box_with_check:cache_recording: 1.07s -> 1.07s [-0.54%, +0.59%]
• ❗🐌without_cache: 2.85s -> 2.87s [+0.08%, +1.19%]

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