test_that("make sure predsErrorCheckF is working correctly", {
  
  skip_on_cran()
  skip_if_not_installed('rstanarm')
  skip_if_not_installed('tibble')
  
  testData <- data.frame(
    y = rnorm(10),
    a = rnorm(10)
  )
  
  freqModel <- lm(y ~ a, data=testData)

  expect_error(predsErrorCheckF(freqModel, at=list(a=c(1,2,3)), centrality='mean'), regexp="The model must be a 'stanreg' object!")
  expect_error(predsErrorCheckF(logitModel, at=list(f=c(1,2,3)), centrality='mean'), regexp="The names for the at values don't match up with the names in the model data!")

})