EmilHvitfeldt · Sep 17, 2026 · Sep 17, 2026
diff --git a/R/bootci.R b/R/bootci.R
@@ -359,7 +359,7 @@ t_single <- function(stats, std_err, is_orig, alpha = 0.05) {
       "{.arg is_orig} should be a logical column the same length as {.arg stats} with no missing values."
     )
   }
-  if (length(stats) != length(std_err) && length(stats) != length(is_orig)) {
+  if (length(stats) != length(std_err) || length(stats) != length(is_orig)) {
     function_args <- c('stats', 'std_err', 'is_orig')
     cli_abort("{.arg {function_args}} should have the same length.")
   }

diff --git a/man/bootstraps.Rd b/man/bootstraps.Rd
diff --git a/man/clustering_cv.Rd b/man/clustering_cv.Rd
diff --git a/man/group_bootstraps.Rd b/man/group_bootstraps.Rd
diff --git a/man/group_mc_cv.Rd b/man/group_mc_cv.Rd
diff --git a/man/group_vfold_cv.Rd b/man/group_vfold_cv.Rd
diff --git a/man/initial_split.Rd b/man/initial_split.Rd
diff --git a/man/initial_validation_split.Rd b/man/initial_validation_split.Rd
diff --git a/man/int_pctl.Rd b/man/int_pctl.Rd
diff --git a/man/mc_cv.Rd b/man/mc_cv.Rd
diff --git a/man/reg_intervals.Rd b/man/reg_intervals.Rd
diff --git a/man/rolling_origin.Rd b/man/rolling_origin.Rd
diff --git a/man/rsample-package.Rd b/man/rsample-package.Rd
diff --git a/man/slide-resampling.Rd b/man/slide-resampling.Rd
diff --git a/man/tidy.rsplit.Rd b/man/tidy.rsplit.Rd
diff --git a/man/validation_split.Rd b/man/validation_split.Rd
diff --git a/man/vfold_cv.Rd b/man/vfold_cv.Rd
diff --git a/tests/testthat/_snaps/bootci.md b/tests/testthat/_snaps/bootci.md
@@ -190,6 +190,30 @@
       Error in `int_pctl()`:
       ! All statistics must be numeric.
 
+# t_single() errors when stats, std_err, and is_orig lengths mismatch
+
+    Code
+      rsample:::t_single(stats, std_err[-1], is_orig)
+    Condition
+      Error in `rsample:::t_single()`:
+      ! `stats`, `std_err`, and `is_orig` should have the same length.
+
+---
+
+    Code
+      rsample:::t_single(stats, std_err, is_orig[-1])
+    Condition
+      Error in `rsample:::t_single()`:
+      ! `stats`, `std_err`, and `is_orig` should have the same length.
+
+---
+
+    Code
+      rsample:::t_single(stats, std_err[-1], is_orig[-1])
+    Condition
+      Error in `rsample:::t_single()`:
+      ! `stats`, `std_err`, and `is_orig` should have the same length.
+
 # checks for apparent bootstrap
 
     Code

diff --git a/tests/testthat/test-bootci.R b/tests/testthat/test-bootci.R
@@ -291,6 +291,26 @@ test_that("bad input", {
   })
 })
 
+test_that("t_single() errors when stats, std_err, and is_orig lengths mismatch", {
+  stats <- rnorm(10)
+  std_err <- rep(1, 10)
+  is_orig <- c(TRUE, rep(FALSE, 9))
+
+  expect_no_error(rsample:::t_single(stats, std_err, is_orig))
+
+  expect_snapshot(error = TRUE, {
+    rsample:::t_single(stats, std_err[-1], is_orig)
+  })
+
+  expect_snapshot(error = TRUE, {
+    rsample:::t_single(stats, std_err, is_orig[-1])
+  })
+
+  expect_snapshot(error = TRUE, {
+    rsample:::t_single(stats, std_err[-1], is_orig[-1])
+  })
+})
+
 test_that("checks for apparent bootstrap", {
   rs_boot <- bootstraps(mtcars, times = 10, apparent = FALSE)
   expect_snapshot(error = TRUE, {