tests/testthat/test-smote_impl.R

In themis: Extra Recipes Steps for Dealing with Unbalanced Data

set.seed(1234)
test_that("samples stay inside convex hull of data.", {
  rdata <- matrix(c(0, 1, 1, 0, 0, 0, 1, 1), ncol = 2)

  expect_true(all(dplyr::between(smote_data(rdata, 3, 100), 0, 1)))
})

test_that("order doesn't matter", {
  df <- data.frame(
    target = rep(c("Yes", "No"), c(10, 50)),
    x = rep(1:2, c(10, 50))
  )
  expect_equal(100, nrow(themis:::smote_impl(df, "target", 5, 1)))

  df <- data.frame(
    target = rep(c("Yes", "No"), c(50, 10)),
    x = rep(1:2, c(50, 10))
  )
  expect_equal(100, nrow(themis:::smote_impl(df, "target", 5, 1)))
})


test_that("smote() interfaces correctly", {
  circle_example_num <- circle_example[, 1:3]

  expect_error(smote(circle_example_num, var = "class"), NA)

  expect_snapshot(error = TRUE,
    smote(circle_example_num, var = "Class")
  )

  expect_snapshot(error = TRUE,
    smote(circle_example_num, var = c("class", "x"))
  )

  expect_snapshot(error = TRUE,
    smote(circle_example_num, var = "x")
  )

  circle_example0 <- circle_example_num
  circle_example0[1, 1] <- NA

  expect_snapshot(error = TRUE,
    smote(circle_example0, var = "class")
  )

  expect_snapshot(error = TRUE,
    smote(circle_example_num, var = "class", k = 0)
  )

  expect_snapshot(error = TRUE,
    smote(circle_example_num, var = "class", k = -1)
  )

  expect_snapshot(error = TRUE,
    smote(circle_example_num, var = "class", k = c(5, 10))
  )
})

test_that("ordering of columns shouldn't matter", {
  data("credit_data", package = "modeldata")

  credit_data0 <- credit_data %>%
    filter(!is.na(Job)) %>%
    select(Job, Time, Age, Expenses)

  expect_error(
    smote(credit_data0, "Job", over_ratio = 1),
    NA
  )
})

test_that("Doesn't error if no upsampling is done (#119)", {
  dat <- data.frame(
    outcome = c(rep("X", 101), rep("Z", 50)),
    X1 = 1)

  expect_no_error(
    smote_impl(dat, "outcome", 5, over_ratio = 0.5)
  )
})