add unit test

tests/testthat/test-calculate_study_day.R

@@ -0,0 +1,63 @@
+AE <- data.frame(
+  USUBJID = c("study123-123", "study123-124", "study123-125"),
+  AESTDTC = c("2012-01-01", "2012-04-14", "2012-04-14")
+)
+DM <- data.frame(
+  USUBJID = c("study123-123", "study123-124", "study123-125"),
+  RFSTDTC = c("2012-02-01", "2012-04-14", NA_character_)
+)
+
+test_that("`calculate_study_day()` works as epxected for bad input", {
+  expect_error(
+    calculate_study_day("a", "b", "C", "D", "E"),
+    "sdtm_in is not a data frame"
+  )
+  expect_error(
+    calculate_study_day(iris, "b", "C", "D", "E"),
+    "dm_domain is not a data frame"
+  )
+  expect_error(
+    calculate_study_day(iris, iris, "c", "d", "e"),
+    "dm_domain needs to have the variable of refdt"
+  )
+  expect_error(
+    calculate_study_day(iris, iris, "Species", "d", "e"),
+    "sdtm_in needs to have the variable of tgdt"
+  )
+  expect_error(
+    calculate_study_day(iris, iris, "Species", "Petal.Length", "e"),
+    "needs to have the variable of merge_key"
+  )
+  expect_error(
+    calculate_study_day(iris, iris, "Species", "Petal.Length", 123, "Species"),
+    "study_day_var is not a character vector"
+  )
+  expect_warning(
+    calculate_study_day(AE, DM, "RFSTDTC", "AESTDTC", "AENDY"),
+    "Target date and the returned study day doesn't match."
+  )
+
+  DM1 <- data.frame(
+    USUBJID = c("study123-123", "study123-123", "study123-125"),
+    RFSTDTC = c("2012-02-01", "2012-04-14", "2012-04-14")
+  )
+  expect_warning(
+    calculate_study_day(AE, DM1, "RFSTDTC", "AESTDTC", "AESTDY"),
+    "Reference date is not unique for each patient!"
+  )
+
+  DM2 <- data.frame(
+    USUBJID = c("study123-123", "study123-124", "study123-125"),
+    RFSTDTC = c(123, 456, 789)
+  )
+  expect_warning(
+    calculate_study_day(AE, DM2, "RFSTDTC", "AESTDTC", "AESTDY"),
+    "Encountered errors when converting refdt to dates."
+  )
+})
+
+test_that("`calculate_study_day()` works as epxected for good input", {
+  res <- calculate_study_day(AE, DM, "RFSTDTC", "AESTDTC", "AESTDY")
+  expected <- c(-31, 1, NA)
+  expect_equal(res$AESTDY, expected)
+})