test_that("`update_alpha()` works as expected", {
    expect_equal(update_alpha("blue", 0.5), "#0000FF80")
    expect_equal(update_alpha(list(c("blue", "red")), NA), c("#0000FFFF", "#FF0000FF"))
    expect_equal(update_alpha("#00FF0080", NA), "#00FF0080")
    expect_equal(update_alpha("#FF000080", 0.25), "#FF000040")

    expect_error(update_alpha(list("blue", "red"), NA))
    skip_if_not(getRversion() >= "4.1.0")
    expect_equal(update_pattern_alpha("red", 0.5, name = "nonrandom"),
                 pattern(rectGrob(name = "nonrandom"), gp = gpar(fill = "#FF000080")))
    expect_equal(update_pattern_alpha(linearGradient(c("black", "white")), 0.5),
                 linearGradient(c("#00000080", "#FFFFFF80")))
})

test_that("`mean_col()` works as expected", {
    expect_equal(mean_col("black", "white"), "#B4B4B4FF")
    expect_equal(mean_col(c("black", "white")), "#B4B4B4FF")
    expect_equal(mean_col("red", "blue"), "#B400B4FF")
})

test_that("`get_params()` works as expected", {
    params <- get_params()
    expect_equal(params$pattern_colour, "grey20")
    expect_equal(params$pattern_fill, "grey80")
    expect_equal(params$pattern_angle, 30)
    expect_equal(params$pattern_density, 0.2)
    expect_equal(params$pattern_spacing, 0.05)
    expect_equal(params$pattern_xoffset, 0)
    expect_equal(params$pattern_yoffset, 0)
    expect_equal(params$pattern_alpha, NA_real_)
    expect_equal(params$pattern_linetype, 1)
    expect_equal(params$pattern_linewidth, 1)

    params <- get_params(alpha = 0.5, spacing = 0.1)
    expect_equal(params$pattern_alpha, 0.5)
    expect_equal(params$pattern_spacing, 0.1)

    gp <- gpar(col = "blue", lty = 2)
    params <- get_params(gp = gp)
    expect_equal(params$pattern_colour, "blue")
    expect_equal(params$pattern_linetype, 2)
})

test_that("`star_scale()` works as expected", {
   # |8/3| star has internal angle 45 degrees and external angle 90 degrees
   scale <- star_scale(8, 45)
   scale2 <- star_scale(8, 90, external = TRUE)
   expect_equal(scale, scale2)
   expect_equal(star_angle(8, scale), 45)
   expect_equal(star_angle(8, scale, external = TRUE), 90)
   expect_equal(star_angle(2, star_scale(2, 30)), 30)
   expect_equal(star_angle(2, star_scale(2, 210, TRUE), TRUE), 210)
})

test_that("`assert_patterns_unique()` works as expected", {
    expect_null(assert_patterns_unique(list(), list()))
    expect_null(assert_patterns_unique(list(custom1 = 2), list(custom2 = 2)))
    expect_error(assert_patterns_unique(list(custom = 2, custom = 3), list()),
                 'There are multiple custom "geometry" patterns named "custom"')
    expect_error(assert_patterns_unique(list(), list(custom = 2, custom = 3)),
                 'There are multiple custom "array" patterns named "custom"')
    expect_error(assert_patterns_unique(list(custom = 2), list(custom = 2)),
                 'There is a custom "geometry" pattern and custom "array" pattern both named "custom"')
    expect_error(assert_patterns_unique(list(circle = 2), list()),
                 'There is a custom "geometry" pattern and builtin \\{gridpattern\\} pattern both named "circle"')
    expect_error(assert_patterns_unique(list(), list(image = 2)),
                 'There is a custom "array" pattern and builtin \\{gridpattern\\} pattern both named "image"')
})

test_that("`assert_suggested()` works as expected", {
    expect_error(assert_suggested("doesnotexist", "blueberry"),
                 "The suggested package \\{doesnotexist\\} must be installed")
})