test(resampling): test for empty test set in holdout

m-muecke · m-muecke · commit 95a3df761eb1 · 2025-09-09T23:32:21.000+02:00
diff --git a/R/partition.R b/R/partition.R
@@ -10,8 +10,8 @@ partition.TaskFcst = function(task, ratio = 0.67) {
   } else {
     ratio[3L] = 1 - (ratio[1L] + ratio[2L])
   }
-  r1 = rsmp("fcst.holdout", ratio = ratio[1L])$instantiate(task)
 
+  r1 = rsmp("fcst.holdout", ratio = ratio[1L])$instantiate(task)
   task$row_roles$use = r1$test_set(1L)
   r2 = rsmp("fcst.holdout", ratio = ratio[2L] / (1 - ratio[1L]))$instantiate(task)
 
diff --git a/tests/testthat/test_resampling_holdout.R b/tests/testthat/test_resampling_holdout.R
@@ -35,6 +35,10 @@ test_that("fcst.holdout basic properties", {
   expect_length(resampling$train_set(1L), task$nrow - 10L)
   expect_length(resampling$test_set(1L), 10L)
 
+  resampling = rsmp("fcst.holdout", ratio = 1.0)$instantiate(task)
+  expect_length(resampling$train_set(1L), task$nrow)
+  expect_length(resampling$test_set(1L), 0L)
+
   # task with a key
   task = tsk("livestock")
   resampling = rsmp("fcst.holdout", ratio = 0.8)
@@ -59,6 +63,11 @@ test_that("fcst.holdout works", {
   resampling$instantiate(task)
   expect_identical(resampling$train_set(1L), 1:72)
   expect_identical(resampling$test_set(1L), 73:144)
+
+  resampling = rsmp("fcst.holdout", ratio = 1.0)
+  resampling$instantiate(task)
+  expect_identical(resampling$train_set(1L), 1:144)
+  expect_identical(resampling$test_set(1L), integer())
 })
 
 test_that("fcst.holdout repeated instantiation", {

Original file line number	Diff line number	Diff line change
`@@ -10,8 +10,8 @@ partition.TaskFcst = function(task, ratio = 0.67) {`
`10`	`10`	`} else {`
`11`	`11`	`ratio[3L] = 1 - (ratio[1L] + ratio[2L])`
`12`	`12`	`}`
`13`		`- r1 = rsmp("fcst.holdout", ratio = ratio[1L])$instantiate(task)`
`14`	`13`
	`14`	`+ r1 = rsmp("fcst.holdout", ratio = ratio[1L])$instantiate(task)`
`15`	`15`	`task$row_roles$use = r1$test_set(1L)`
`16`	`16`	`r2 = rsmp("fcst.holdout", ratio = ratio[2L] / (1 - ratio[1L]))$instantiate(task)`
`17`	`17`