tests/testthat/test-40-alpha.R

In jonclayden/shades: Simple Colour Manipulation

context("Working with transparency")

test_that("opacity can be obtained and manipulated", {
    expect_equal(opacity("red"), 1)
    expect_equal(opacity("#FF000080"), 128/255)
    expect_equal(opacity(saturation("#FF000080",0.5)), 128/255)
    expect_equal(warp("#FF000080","HSV"), "#FF000080", hexonly=TRUE)
    
    expect_equal(opacity("red",c(0,0.5)), c("#FF000000","#FF000080"), hexonly=TRUE)
    expect_equal(opacity("red",delta(-0.5)), "#FF000080", hexonly=TRUE)
    expect_null(attr(opacity("#FF000080",delta(0.5)),"alpha"))
    
    shades <- shade(c("red","green","blue"))
    matrix <- rep(shades, 2)
    dim(matrix) <- c(3L,2L)
    
    expect_null(attr(shades,"alpha"))
    expect_equal(opacity(c(shades,"#00000000")), c(1,1,1,0))
    shades[2] <- "#00FF0000"
    expect_equal(attr(shades,"alpha"), c(1,0,1))
    expect_equal(dim(opacity(matrix,0.5)), c(3L,2L))
    expect_equal(dim(opacity(matrix,recycle(0.4,0.6))), c(3L,2L))
    
    expect_true(shade("#FF8080") == shade("#FF8080FF"))
    expect_false(shade("#FF8080") == shade("#FF8080DD"))
    expect_match(all.equal(shade("#FF8080"), "#FF8080DD"), "Alpha values do not match")
})