Closes #2582 update derive_vars_period

NEWS.md

@@ -10,6 +10,7 @@
 
 - Remove `dthcaus_source()` calls in `ADSL` template because they are deprecated. (#2517)
 - Update `ADEG` template to flag `ABLFL` and `ANL01FL` based on `DTYPE == "AVERAGE"` records. (#2561)
+- Update `derive_vars_period` to make it work when there is only one new variable. (#2582)
 
 ## Updates of Existing Functions
 

R/period_dataset.R

@@ -419,6 +419,7 @@ derive_vars_period <- function(dataset,
   ref_wide <- pivot_wider(
     ref_stripped,
     names_from = vars2chr(id_vars),
+    names_glue = sprintf("{.value}_%s", paste0(sprintf("{%s}", vars2chr(id_vars)), collapse = "_")),
     values_from = unname(new_vars_chr)
   )
 

tests/testthat/test-period_dataset.R

@@ -433,3 +433,44 @@ test_that("derive_vars_period Test 13: periods", {
     keys = c("USUBJID")
   )
 })
+
+## Test 14: Periods derived even when only when one period variable needed ----
+test_that("derive_vars_period Test 13: periods", {
+  expected <- tibble::tribble(
+    ~USUBJID, ~AP01SDT,
+    "1",      "2021-01-04",
+    "2",      "2021-02-02",
+  ) %>%
+    mutate(
+      across(matches("AP\\d\\d[ES]DT"), ymd)
+    ) %>%
+    mutate(
+      STUDYID = "xyz"
+    )
+
+  period_ref <- tibble::tribble(
+    ~USUBJID, ~APERIOD, ~APERSDT,     ~APEREDT,     ~APERSDTM,             ~APEREDTM,
+    "1",             1, "2021-01-04", "2021-02-06", "2021-01-04 10:01:02", "2021-02-06 14:03:04",
+    "2",             1, "2021-02-02", "2021-03-02", "2021-02-02 04:11:34", "2021-03-02 16:55:59"
+  ) %>%
+    mutate(
+      STUDYID = "xyz",
+      APERIOD = as.integer(APERIOD),
+      APERSDT = ymd(APERSDT),
+      APEREDT = ymd(APEREDT),
+      APERSDTM = ymd_hms(APERSDTM),
+      APEREDTM = ymd_hms(APEREDTM)
+    )
+
+  adsl <- tibble::tibble(STUDYID = "xyz", USUBJID = c("1", "2"))
+
+  expect_dfs_equal(
+    base = expected,
+    compare = derive_vars_period(
+      adsl,
+      dataset_ref = period_ref,
+      new_vars = exprs(APxxSDT = APERSDT)
+    ),
+    keys = c("USUBJID")
+  )
+})