corrected coercion for dates and added tests

Author: douwe

R/utils.R

@@ -112,6 +112,10 @@ coerce <- function(x, atomicclass) {
          "numeric" = as.numeric(x),
          "integer" = as.integer(x),
          "logical" = as.logical(x),
-         "date" = as.POSIXct(as.integer(x))
+         "date" = if (inherits(x, "POSIXct") || inherits(x, "Date")) {
+           as.Date(x)
+          } else {
+            as.Date(as.integer(x), origin="1899-12-30")
+          },
         )
 }

tests/testthat/test-utils.R

@@ -38,3 +38,28 @@ test_that("function kvlist_to_table works", {
   guide <- list(otherstuff = list("a" = "A", "b" = "B"))
   expect_error(kvlist_to_table(kvlist, guide, reverse.translate = TRUE))
 })
+
+test_that("function coerce works", {
+  expect_equal(as.character(coerce(45748L, "date")), "2025-04-01")
+  expect_equal(as.character(coerce(as.Date("2025-04-01"), "date")), "2025-04-01")
+  expect_equal(coerce("45748", "integer"), 45748L)
+  expect_equal(coerce("45748", "numeric"), 45748)
+  expect_equal(coerce(45748L, "character"), "45748")
+  expect_equal(coerce("true", "logical"), TRUE)
+})
+
+test_that("Reading dates from an excel file yield correct dates", {
+  excel_file <- test_path("testdata/dates_linux.xlsx")
+  date1 <- readxl::read_excel(excel_file, sheet=1, range="A1:A2")
+  date2 <- readxl::read_excel(excel_file, sheet=1, range="B1:B2")
+  date3 <- readxl::read_excel(excel_file, sheet=1, range="C1:C2")
+  expect_equal(coerce(date1 |> dplyr::pull(1), "date"), as.Date("1962-10-27"))
+  expect_equal(coerce(date2 |> dplyr::pull(1), "date"), as.Date("1962-10-27"))
+  expect_equal(coerce(date3 |> dplyr::pull(1), "date"), as.Date("1962-10-27"))
+  date4 <- readxl::read_excel(excel_file, sheet=1, range="D1:D2")
+  date5 <- readxl::read_excel(excel_file, sheet=1, range="E1:E2")
+  date6 <- readxl::read_excel(excel_file, sheet=1, range="F1:F2")
+  expect_equal(coerce(date4 |> dplyr::pull(1), "date"), as.Date("2025-04-01"))
+  expect_equal(coerce(date5 |> dplyr::pull(1), "date"), as.Date("2025-04-01"))
+  expect_equal(coerce(date6 |> dplyr::pull(1), "date"), as.Date("2025-04-01"))
+})