Merge pull request #194 from rstudio/na-css-color

NEWS

@@ -13,6 +13,8 @@ htmltools 0.5.0.9002
 
 * Closed #189: `validateCssUnit()` now accepts `fit-content`. (#190)
 
+* Closed #161: `parseCssColors(x, mustWork = FALSE)` now returns NA for NA input values instead of throwing an error. (#194)
+
 * `htmlPreserve()` can now optionally use the Pandoc `raw_attribute` extension to enclose HTML.
 
 htmltools 0.5.0

R/colors.R

@@ -30,6 +30,16 @@
 #' @md
 #' @export
 parseCssColors <- function(str, mustWork = TRUE) {
+  # Logic below assumes a character string with non-missing values
+  # Note that an empty string is not a valid color, so parsing fails
+  # on NA input values, and thus, will be converted back to NA
+  # when `mustWork = FALSE`
+  isNA <- is.na(str)
+  if (!(is.character(str) || all(isNA))) {
+    stop("`str` must be a character vector (or NA).")
+  }
+  str[isNA] <- ""
+
   # Strip insignificant whitespace
   str <- color_strip_ws(str)
 

tests/testthat/test-colors.R

@@ -119,3 +119,23 @@ test_that("decode_color_keyword", {
   expect_error(decode_color_keyword(" orange "))
   expect_error(decode_color_keyword(NA))
 })
+
+test_that("parseCssColors() handles incoming NA values sensibly", {
+  expect_error(parseCssColors(NA))
+  expect_identical(
+    parseCssColors(NA, mustWork = FALSE),
+    NA_character_
+  )
+  expect_identical(
+    parseCssColors(rep(NA, 2), mustWork = FALSE),
+    rep(NA_character_, 2)
+  )
+  expect_identical(
+    parseCssColors(c(NA, "red"), mustWork = FALSE),
+    c(NA, "#FF0000")
+  )
+  expect_identical(
+    parseCssColors(c(NA, "blue", "notacolor"), mustWork = FALSE),
+    c(NA, "#0000FF", NA)
+  )
+})