fix: address review round 1 for #7

R/theme.R

@@ -87,6 +87,9 @@
 #' ggplot(mpg, aes(displ, hwy)) +
 #'   geom_point() +
 #'   theme_civilytics(font_size = 18)
+#'
+#' # Note: for fully-transparent PNGs, also set a transparent device
+#' # background (e.g. `ggsave("plot.png", bg = NA)`).
 #' }
 theme_civilytics <- function(
     font_size    = 14,

tests/testthat/test_theme.R

@@ -137,6 +137,7 @@ test_that("theme_civilytics has transparent background by default", {
   th <- theme_civilytics()
   expect_true(is.na(th$plot.background$fill))
   expect_true(is.na(th$panel.background$fill))
+  expect_null(th$legend.background$fill)
 })
 
 test_that("theme_civilytics paper_bg=TRUE opt-in fills with cream", {