tests/testthat/test-md_compute_mld.R

In PIP-Technical-Team/wbpip: What the Package Does (One Line, Title Case)

df <- readRDS(test_path("testdata", "md_lorenz3.rds"))

test_that("md_compute_mld() returns consistent variable type", {
  out <- md_compute_mld(
    welfare = df$welfare,
    weight = df$weight
  )
  expect_equal(length(out), 1)
  expect_true(is.numeric(out))
})

test_that("md_compute_mld() returns expected results for know distribution", {
  out <- md_compute_mld(
    welfare = df$welfare,
    weight = df$weight
  )
  expect_equal(out, 0.7502036651)
})


test_that("md_compute_mld() returns expected results for perfect equality", {
  # Test for perfect equality
  out <- md_compute_mld(welfare = rep(2, 1000), weight = rep(1, 1000))
  expect_equal(out, 0)
})

test_that("md_compute_mld() returns expected results for perfect inequality", {
  # Test for perfect inequality
  # MLD should be positive
  # out <- md_compute_mld(welfare = c(rep(0, 9999), 10000))
  # expect_true(out > 0)
  out <- md_compute_mld(welfare = c(rep(1, 9999), 10000), weight = rep(1, 10000))
  expect_true(out > 0)
})

test_that("md_compute_mld() values change in the expected direction", {
  # Compare MLD values for two known distributions
  lower_expected_mld <- md_compute_mld(
    welfare = c(rep(20, 999), 10000),
    weight = rep(1, 1000)
  ) # Less inequal
  higher_expected_mld <- md_compute_mld(
    welfare = c(rep(20, 999), 100000),
    weight = rep(1, 1000)
  ) # More inequal
  expect_true(lower_expected_mld < higher_expected_mld)
})