add test

Author: teunbrand

tests/testthat/_snaps/theme.md

@@ -98,3 +98,8 @@
 
     The `aspect.ratio` theme element must be a <numeric/integer> object.
 
+# theme() warns about conflicting palette options
+
+    The `options('ggplot2.discrete.colour')` setting is incompatible with the `palette.colour.discrete` theme setting.
+    i You can set `options(ggplot2.discrete.colour = NULL)`.
+

tests/testthat/test-theme.R

@@ -710,6 +710,16 @@ test_that("margin_part() mechanics work as expected", {
   expect_equal(as.numeric(test), c(5.5, 5.5, 11, 5.5))
 })
 
+test_that("theme() warns about conflicting palette options", {
+  expect_silent(
+    theme(palette.colour.discrete = c("dodgerblue", "orange"))
+  )
+  local_options(ggplot2.discrete.colour = c("red", "purple"))
+  expect_snapshot_warning(
+    theme(palette.colour.discrete = c("dodgerblue", "orange"))
+  )
+})
+
 # Visual tests ------------------------------------------------------------
 
 test_that("element_polygon() can render a grob", {