tests/testthat/test-assert.R

In assertions: Simple Assertions for Beautiful and Customisable Error Messages

cli::test_that_cli("assert() works", configs = "plain", {
  # Test that expressions that are TRUE do not raise an error
  expect_identical(assert(1 == 1, 2 < 3, 5 > 1), TRUE)

  # Test that expressions that are FALSE do raise an error
  expect_error(assert(1 == 2, 2 < 3, 5 > 1), "The following assertions failed:\nx `1 == 2`", fixed = TRUE)
  expect_error(assert(1 == 1, 2 < 1, 5 > 1), "The following assertions failed:\nx `2 < 1`", fixed = TRUE)

  # Test that custom error messages work
  expect_error(assert(1 == 2, 2 < 1, 5 > 1, msg = "Custom error message"), "Custom error message", fixed = TRUE)

  # Test that expressions containing variables work correctly
  x <- 1
  y <- 2
  expect_error(assert(x == y, y < 1, 5 > 1), "The following assertions failed:\nx `x == y`\nx `y < 1`", fixed = TRUE)
})


cli::test_that_cli(configs = "plain", "assert(): user supplied custom error messages have access to the environment of its parent function", {

  foo <- function(){
    name = "billy"
    assert(FALSE, msg = "{name} was always going to fail")

  }
  expect_error(foo(), "billy was always going to fail", fixed=TRUE)
})