Modernize pipe operator and recode() usage

[jt14den]

Summary

• Converts %>% to the native pipe |> throughout episodes 1, 3, 4, and 5, matching the current tidyverse style guide recommendation for R 4.1+ (this lesson already requires R 4.5+ per renv.lock).
• Replaces dplyr::recode(), which is marked [Superseded] on the current dplyr reference page, with case_match() in episodes 3 and 5. Each conversion includes an explicit .default argument to preserve recode()'s pass-through behavior for any value not in the mapping list, since case_match() returns NA for unmatched values by default.
• Updates the accompanying prose (objectives, section headings, exercise text, keypoints) to match.

Test plan

• sandpaper::validate_lesson() passes with no errors
• All four modified episodes knit cleanly from a fresh session with no rendered R errors
• Verified case_match() output is byte-identical to recode() output when run against the actual episodes/data/books.csv for both subCollection and format
• Confirmed every raw code value in the dataset is covered by the mapping list, so .default is a safety net rather than currently masking a data problem
• Would appreciate a second read on the case_match() conversions in episode 3 (lines ~203, ~221, ~551) and episode 5 (lines ~43, ~59, ~156) before merge, since this is a real behavioral change to double-check, not just a rename

[github-actions]

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Rendered Changes

🔍 Inspect the changes: https://github.com/LibraryCarpentry/lc-r/compare/md-outputs..md-outputs-PR-149

The following changes were observed in the rendered markdown documents:

 01-intro-to-r.md                                   |   10 +-
 02-starting-with-data.md                           |    2 +-
 03-data-cleaning-and-transformation.md             |  173 +-
 04-data-viz-ggplot.md                              |   18 +-
 05-reproducible-reports.md                         |    6 +-
 config.yaml (gone)                                 |   86 -
 ...t-rendered-boxplot-exercise-subcollection-1.png |  Bin 49562 -> 49340 bytes
 ...a-viz-ggplot-rendered-boxplot-with-points-1.png |  Bin 42909 -> 42953 bytes
 ...data-viz-ggplot-rendered-unnamed-chunk-14-1.png |  Bin 39625 -> 39407 bytes
 fig/04-data-viz-ggplot-rendered-violin-plot-1.png  |  Bin 38570 -> 38763 bytes
 ...oducible-reports-rendered-plot-high-usage-1.png |  Bin 46952 -> 47007 bytes
 md5sum.txt                                         |   32 +-
 renv.lock (gone)                                   | 3962 --------------------
 13 files changed, 130 insertions(+), 4159 deletions(-)

What does this mean?

If you have source files that require output and figures to be generated (e.g. R Markdown), then it is important to make sure the generated figures and output are reproducible.

This output provides a way for you to inspect the output in a diff-friendly manner so that it's easy to see the changes that occur due to new software versions or randomisation.

⏱️ Updated at 2026-08-23 01:42:00 +0000

[nickyjgarland]

The changes in syntax all seem fine but while checking case_match() as a replacement I noted in the documentation that this function was also depreciated. Is there a benefit of using this function or should we switch to a suggested alternative such as recode_values()?