In collapse_rows, added clean_cut, swapped the default order of latex_hline and added some warning message.
diff --git a/tests/visual_tests/collapse_rows_pdf.Rmd b/tests/visual_tests/collapse_rows_pdf.Rmd
index 25dc0b9..a95c9f6 100644
--- a/tests/visual_tests/collapse_rows_pdf.Rmd
+++ b/tests/visual_tests/collapse_rows_pdf.Rmd
@@ -7,12 +7,14 @@
 
 ```{r}
 library(knitr)
+library(dplyr)
 library(kableExtra)
 collapse_rows_dt <- data.frame(C1 = c(rep("aaaaaa aaaaaa", 10), rep("bbbbb bbbbbb", 5)),
-                 C2 = c(rep("c", 7), rep("d", 4), rep("c", 2), rep("d", 2)),
+                 C2 = c(rep("c", 7), rep("d", 3), rep("c", 3), rep("d", 2)),
                  C3 = 1:15,
                  C4 = sample(c(0,1), 15, replace = TRUE))
-kable(collapse_rows_dt, "latex", align = "c") %>%
+kable(bind_rows(collapse_rows_dt, collapse_rows_dt, collapse_rows_dt, collapse_rows_dt), "latex", align = "c", booktabs = T, longtable= T) %>%
   column_spec(1, bold = T, width = "5em") %>%
-  collapse_rows(1:2)
+  collapse_rows(1:2, latex_hline = "full", longtable_clean_cut = T) %>%
+  cat()
 ```