support writing tibbles. closes #581 (#582)

* support writing tibbles

* General solution for data.table and tibble suggested by @jmbarbone

NEWS.md

@@ -8,6 +8,8 @@
 
 * Add `skipHiddenCols` and `skipHiddenRows` to `wb_to_df()`. In this way, hidden columns and rows are ignored, assuming that the person who has hidden them assumes that they are not important. [579](https://github.com/JanMarvin/openxlsx2/pull/579)
 
+* When writing `tibble` use `to.data.frame()` just like in the `data.table` case. [582](https://github.com/JanMarvin/openxlsx2/pull/582)
+
 
 ***************************************************************************
 

R/write.R

@@ -258,7 +258,7 @@ write_data2 <- function(
   if (inherits(data, "data.frame") || inherits(data, "matrix")) {
     is_data_frame <- TRUE
 
-    if (inherits(data, "data.table")) data <- as.data.frame(data)
+    if (is.data.frame(data)) data <- as.data.frame(data)
 
     sel <- !dc %in% c(4, 5, 10)
     data[sel] <- lapply(data[sel], as.character)

tests/testthat/test-write.R

@@ -509,3 +509,21 @@ test_that("writing na.strings = NULL works", {
   expect_equal(exp, got)
 
 })
+
+test_that("write tibbles", {
+
+  tbl <- structure(
+    list(
+      a_number = c(1234, 4321),
+      a_string = c("hello", "world"),
+      a_date = structure(c(19358, 19448), class = "Date"),
+      a_boolean = c(FALSE, TRUE)
+    ),
+    class = c("tbl_df", "tbl", "data.frame"),
+    row.names = c(NA, -2L)
+  )
+
+  wb <- wb_workbook() %>%
+    wb_add_worksheet() %>%
+    wb_add_data(x = tbl)
+})