make get_legend() test conditional

tests/testthat/test_get_legend.R

@@ -10,6 +10,14 @@ test_that("get legend", {
   expect_equal(l$name, "guide-box")
 
   # return null legend if no legend
-  expect_s3_class(get_legend(p + theme(legend.position = "none")), "zeroGrob")
+  # Note by Teun: It is yet unclear to me what the desired behaviour of
+  # `get_legend()` is in the face of multiple legends.
+  # For now, this test is conditional on ggplot2 version, but this is
+  # more of a duct tape solution than a reflection of the intended behaviour
+  if (utils::packageVersion("ggplot2") >= "3.5.0") {
+    expect_s3_class(get_legend(p + theme(legend.position = "none")), "zeroGrob")
+  } else {
+    expect_null(get_legend(p + theme(legend.position = "none")))
+  }
 })