test mcmc_hex throws same errors as scatter if nparams != 2

Author: jgabry

tests/testthat/test-mcmc-scatter-and-parcoord.R

@@ -1,6 +1,6 @@
 library(bayesplot)
 suppressPackageStartupMessages(library(rstanarm))
-context("MCMC: scatter and parallel coordinates plots")
+context("MCMC: scatter, hex, and parallel coordinates plots")
 
 source(test_path("data-for-mcmc-tests.R"))
 
@@ -15,6 +15,8 @@ divs <- sample(c(0,1), size = 1000, prob = c(0.25, 0.75), replace = TRUE)
 np$Value[np$Parameter=="divergent__"] <- divs # fake divergences
 
 
+
+# mcmc_scatter/hex --------------------------------------------------------
 test_that("mcmc_scatter returns a ggplot object", {
   expect_gg(mcmc_scatter(arr, pars = c("beta[1]", "beta[2]")))
   expect_gg(mcmc_scatter(arr1chain, regex_pars = "beta", size = 3, alpha = 0.5))
@@ -24,13 +26,8 @@ test_that("mcmc_scatter returns a ggplot object", {
                          pars = c("sigma", "(Intercept)")))
 })
 
-test_that("mcmc_hex returns a ggplot object", {
-  skip_if_not_installed("hexbin")
-  expect_gg(mcmc_hex(arr, pars = c("beta[1]", "beta[2]")))
-  expect_gg(mcmc_hex(arr1chain, regex_pars = "beta", binwidth = c(.5,.5)))
-})
-
-test_that("mcmc_scatter throws error if only 1 parameter", {
+test_that("mcmc_scatter throws error if number of parameters is not 2", {
+  expect_error(mcmc_scatter(arr, pars = c("sigma", "beta[1]", "beta[2]")), "exactly 2 parameters")
   expect_error(mcmc_scatter(arr, pars = "sigma"), "exactly 2 parameters")
   expect_error(mcmc_scatter(arr1), "exactly 2 parameters")
   expect_error(mcmc_scatter(mat1), "exactly 2 parameters")
@@ -46,6 +43,21 @@ test_that("mcmc_scatter accepts NUTS info", {
   expect_named(g$data, c("x", "y", "Divergent"))
 })
 
+test_that("mcmc_hex returns a ggplot object", {
+  skip_if_not_installed("hexbin")
+  expect_gg(mcmc_hex(arr, pars = c("beta[1]", "beta[2]")))
+  expect_gg(mcmc_hex(arr1chain, regex_pars = "beta", binwidth = c(.5,.5)))
+})
+
+test_that("mcmc_hex throws error if number of parameters is not 2", {
+  skip_if_not_installed("hexbin")
+  expect_error(mcmc_hex(arr, pars = c("sigma", "beta[1]", "beta[2]")), "exactly 2 parameters")
+  expect_error(mcmc_hex(arr, pars = "sigma"), "exactly 2 parameters")
+  expect_error(mcmc_hex(arr1), "exactly 2 parameters")
+  expect_error(mcmc_hex(mat1), "exactly 2 parameters")
+})
+
+
 
 # mcmc_pairs  -------------------------------------------------------------
 test_that("mcmc_pairs returns a bayesplot_grid object", {