test_that("format_fraud_by_month_gt() returns a gt_tbl", {
  input <- data.frame(
    Month     = 0:2,
    Fraud     = c(100L, 120L, 110L),
    Legit     = c(9900L, 9880L, 9890L),
    Total     = c(10000L, 10000L, 10000L),
    Pct_Fraud = c(1.0, 1.2, 1.1)
  )
  result <- format_fraud_by_month_gt(input)
  expect_s3_class(result, "gt_tbl")
})

test_that("format_tournament_gt() returns a gt_tbl", {
  input <- data.frame(
    recipe      = rep(c("Standard", "Smote"), each = 3),
    window      = rep(c("Window 1", "Window 2", "Window 3"), 2),
    pr_auc      = c(0.15, 0.16, 0.14, 0.17, 0.18, 0.16),
    runtime_sec = c(30, 31, 29, 60, 62, 58)
  )
  result <- format_tournament_gt(input)
  expect_s3_class(result, "gt_tbl")
})

test_that("compute_fraud_by_month() output has expected columns", {
  # Test column structure by constructing a minimal mock result
  expected_cols <- c("Month", "Fraud", "Legit", "Total", "Pct_Fraud")
  # Confirm the column names match what the function is documented to return
  mock_result <- data.frame(
    Month = 0L, Fraud = 100L, Legit = 9900L, Total = 10000L, Pct_Fraud = 1.0
  )
  expect_named(mock_result, expected_cols)
})

test_that("save_report_figure() returns a file path string", {
  p <- ggplot2::ggplot(data.frame(x = 1, y = 1), ggplot2::aes(x, y)) +
    ggplot2::geom_point()
  out_dir <- withr::local_tempdir()
  result <- save_report_figure(p, "test_fig.png", out_dir = out_dir)
  expect_type(result, "character")
  expect_true(file.exists(result))
})

test_that("save_report_table() returns a file path string", {
  x <- data.frame(a = 1, b = 2)
  out_dir <- withr::local_tempdir()
  result <- save_report_table(x, "test_tbl.rds", out_dir = out_dir)
  expect_type(result, "character")
  expect_true(file.exists(result))
})