test_that("performance evaluation works", {
  res <- readRDS(testthat::test_path("data", "res.rds"))
  res <- dplyr::rename(res, K = k)

  results <- performance(res, progress = FALSE)

  only.training <- results$evaluation

  testthat::expect_equal(only.training[1, 9], 0.84, tolerance = 0.01)

  results2 <- performance(res, by = "author", progress = FALSE)

  only.training2 <- results2$evaluation

  testthat::expect_equal(only.training2[1, 9], 0.84, tolerance = 0.01)

  train.test <- split.data.frame(res, ~target)
  same <- train.test$`TRUE`
  diff <- train.test$`FALSE`

  # creating vector of random rows
  training <- rbind(same[1:35, ], diff[1:35, ])
  test <- rbind(same[35:48, ], diff[35:48, ])

  results <- performance(training, test)

  train.test.perf <- results$evaluation

  testthat::expect_equal(train.test.perf[1, 9], 0.785, tolerance = 0.01)
})