tests/testthat/test-colour-manip.R

In scales: Scale Functions for Visualization

# hcl ---------------------------------------------------------------------

test_that("can modify each hcl component", {
  expect_equal(col2hcl("red", h = 180), "#00B793")
  expect_equal(col2hcl("red", l = 50), "#F40000")
  expect_equal(col2hcl("red", c = 50), "#B36B6B")
  expect_equal(col2hcl("red", alpha = 0.5), "#FF000080")
})

# alpha -------------------------------------------------------------------

test_that("missing alpha preserves existing", {
  rgb <- farver::decode_colour(rep("red", 5), to = "rgb")
  alpha <- seq(0, 1, length.out = nrow(rgb))
  reds <- farver::encode_colour(rgb, alpha)

  expect_equal(reds, alpha(reds, NA))
  expect_equal(reds, alpha(reds, rep(NA, 5)))
})

test_that("alpha values recycled to match colour", {
  cols <- farver::encode_colour(farver::decode_colour(c("red", "green", "blue", "pink")))

  expect_equal(cols, alpha(cols, NA))
  expect_equal(cols, alpha(cols, 1))
})

test_that("col values recycled to match alpha", {
  alphas <- round(seq(0, 1, length.out = 3))
  reds <- alpha("red", alphas)
  reds_alpha <- farver::decode_colour(reds, TRUE)[, 4]

  expect_equal(alphas, reds_alpha)
})

test_that("preserves names", {
  x <- c("deeppink", "hotpink", "lightpink")
  expect_named(alpha(x, 0.5), NULL)

  names(x) <- x
  expect_named(alpha(x, 0.5), names(x))
})