tests/testthat/test-error-messages.R

In nomisdata: Access 'Nomis' UK Labour Market Data and Statistics

# Tests for helpful error messages

test_that("error messages are informative", {
  expect_error(
    fetch_nomis(),
    "Dataset ID required"
  )
  
  expect_error(
    get_codes(),
    "Dataset ID.*required"
  )
  
  expect_error(
    aggregate_geography(data.frame(x = 1), "TYPE", "missing"),
    "not found"
  )
})

test_that("missing package errors suggest installation", {
  # Use skip_if_not_installed (reverse logic)
  skip_if_not_installed("rsdmx")
  
  # If rsdmx IS installed, we can't test the error message
  # So we skip this test when rsdmx is available
  skip("rsdmx is installed, cannot test error message")
})

# Alternative test that works regardless
test_that("missing package errors are handled", {
  # Test that functions check for required packages
  # This will pass whether or not rsdmx is installed
  
  if (!requireNamespace("rsdmx", quietly = TRUE)) {
    expect_error(
      lookup_geography("London"),
      "rsdmx.*required|install"
    )
  } else {
    # If rsdmx is installed, just verify function exists
    expect_true(exists("lookup_geography"))
  }
})