Add resolution test

Author: teunbrand

tests/testthat/test-utilities.R

@@ -166,3 +166,11 @@ test_that("vec_rbind0 can combined ordered factors", {
   expect_equal(levels(test$a), c("A", "B", "C"))
 
 })
+
+test_that("resolution() gives correct answers", {
+  expect_equal(resolution(c(4,  6)), 2)
+  expect_equal(resolution(c(4L, 6L)), 1L)
+  expect_equal(resolution(mapped_discrete(c(4, 6))), 1L)
+  expect_equal(resolution(c(0, 0)), 1L)
+  expect_equal(resolution(c(0.5,  1.5), zero = TRUE), 0.5)
+})