improve assert_class()

R/asserts.R

@@ -1,10 +1,15 @@
 # Use arg_nm to override the default name of the argument in case of an error message.
 assert_class <- function(x, class, or_null = FALSE, all = FALSE, package = NULL, envir = parent.frame(), arg_nm = NULL) {
+
   sx <- as.character(substitute(x, envir))
   if (length(sx) == 0 || !is.null(arg_nm)) {
     sx <- arg_nm %||% "argument"
   }
 
+  if (missing(x)) {
+    stop("input ", sx, " is missing", call. = FALSE)
+  }
+
   ok <- if (all) {
     all(vapply(class, function(i) inherits(x, i), NA))
   } else {
@@ -28,7 +33,6 @@ assert_class <- function(x, class, or_null = FALSE, all = FALSE, package = NULL,
   invisible(NULL)
 }
 
-
 assert_chart_sheet <- function(x) assert_class(x, c("wbChartSheet", "R6"), all = TRUE)
 assert_comment     <- function(x) assert_class(x, c("wbComment",    "R6"), all = TRUE)
 assert_color       <- function(x) assert_class(x, c("wbColour"),           all = TRUE)

tests/testthat/test-asserts.R

@@ -20,6 +20,17 @@ test_that("class assertions work", {
   # nolint end
 })
 
+test_that("missing check works", {
+  wb <- wb_workbook()
+  expect_silent(assert_workbook(wb))
+
+  wb <- substitute()
+  expect_error(assert_workbook(wb), "input wb is missing")
+
+  wb <- "Not_a_workbook"
+  expect_error(assert_workbook(wb), "wb must be class wbWorkbook or R6")
+})
+
 test_that("match_oneof() works", {
   expect_identical(match_oneof(1:4, 3:4), 3L)
   expect_identical(match_oneof(1:4, 3:4, several = TRUE), 3:4)