Replace gt dependency with lt

[yihui]

Summary

• Remove the gt package from Imports and replace with the lightweight lt package
• New as_lt() generic + S3 methods for fixed_design_summary and gs_design_summary, fully replacing as_gt()
• All 14 vignettes updated to use lt functions (lt(), lt_header(), lt_spanner(), lt_format(), lt_footnote(), lt_note(), lt_label())
• Tests updated for lt_tbl assertions

Migration mapping

gt	lt
gt::gt(x)	lt(x)
group_by(col) |> gt()	lt(x, row_group = "col")
tab_header(title, subtitle)	lt_header(title, subtitle)
tab_spanner(label, columns)	lt_spanner(label, columns)
fmt_number(columns, decimals)	lt_format(columns, decimals)
tab_footnote(fn, cells_column_labels(col))	lt_footnote(text, "column", columns)
tab_footnote(fn) (no location)	lt_note(text)
cols_label(a = "A")	lt_label(a = "A")

Test plan

• as_lt() unit tests pass for fixed and GS designs
• All design types render correctly (fixed_ahr, gs_ahr, gs_wlr, gs_rd)
• Visual comparison with gt output confirms structural equivalence
• Non-binding design body footnote renders correctly
• Custom footnotes (colname, title, analysis, spanner) all work
• R CMD check passes
• All vignettes build without error

Vignette comparison

This zip archive contains all vignettes and articles built with gt and lt, respectively. You can compare the rendered HTML pages side by side: vignette-compare.zip

Question

Why did we test the LaTeX output of gt::as_latex()?

gsDesign2/tests/testit/helper.R

Line 1 in 7043792

gt_to_latex <- function(data) cat(as.character(gt::as_latex(data)))

[jdblischak]

When I run the tests locally, I get two failures:

library("testit")
test_pkg()
## Error: -- Assertion failed: as_lt: footnote=FALSE removes footnote --
##    1. count_footnotes(z1) (LHS) ==>
##        int 0
##       ----------
##        int 1
##       <== (RHS) 1L
##       count_footnotes(z1) %==% 1L is not TRUE but FALSE at tests/testit/test-developer-as_lt.R#14
##    2. count_footnotes(z1) (LHS) ==>
##        int 0
##       ----------
##        int 2
##       <== (RHS) 2L
##       count_footnotes(z1) %==% 2L is not TRUE but FALSE at tests/testit/test-developer-as_lt.R#22

sessioninfo::package_info(c("gsDesign2", "lt"), dependencies = FALSE)
##  package   * version date (UTC) lib source
##  gsDesign2 * 1.1.8   2026-05-28 [1] local
##  lt          0.0.7   2026-05-28 [1] Github (yihui/lt@e485eb6)
##
##  [1] C:/Users/john/AppData/Local/R/win-library/4.4
##  [2] C:/Program Files/R/R-4.4.3/library
##  * ── Packages attached to the search path.

[yihui]

Just a quick update: I've submitted lt v0.1 to CRAN. Currently there are 132 newbies in the queue. I guess the initial review may take place a week later. Fingers crossed.