tests/testthat/test.stat_spike.R

In ggdist: Visualizations of Distributions and Uncertainty

# Tests for spike plots
#
# Author: mjskay
###############################################################################

suppressPackageStartupMessages({
  library(distributional)
})


test_that("spike works", {
  skip_if_no_vdiffr()

  p = ggplot(data.frame(x = dist_normal()), aes(xdist = x)) +
    stat_slabinterval() +
    stat_spike() +
    stat_spike(at = c(-1.5, 1.5), color = "red") +
    stat_spike(at = qi, color = "green") +
    scale_thickness_shared()

  vdiffr::expect_doppelganger("spike works",
    p
  )
})

test_that("constant distributions work", {
  p = ggplot(data.frame(x = dist_normal(1, 0)), aes(xdist = x))

  test_data = function(plot) as.list(layer_data(plot)[,c("thickness","pdf","cdf","x","ymin","ymax")])
  expect_snapshot_value(test_data(p + stat_spike()), style = "deparse", cran = TRUE)
  expect_snapshot_value(test_data(p + stat_spike(at = 0)), style = "deparse", cran = TRUE)
})