suppressMessages({
  test_that("add_group_id single dataframe works", {
    # Create test data
    test_df <- data.frame(
      category = rep(c("A", "B"), 5),
      value = rnorm(10),
      type = rep(c("X", "Y"), each = 5)
    )

    # Test with one key
    result <- add_group_id(test_df, by = "category")
    expect_equal(max(result$g_id), 2) # Should have 2 groups

    # Test with two keys
    result <- add_group_id(test_df, by = c("category", "type"))
    expect_equal(max(result$g_id), 4) # Should have 4 groups
  })

  test_that("add_group_id two dataframes works", {
    # Create test data
    df1 <- data.frame(
      category = rep(c("A", "B"), 5),
      value = rnorm(10),
      type = rep(c("X", "Y"), each = 5)
    )

    df2 <- data.frame(
      category = rep(c("A", "B"), 5),
      value = rnorm(10),
      type = rep(c("Y", "X"), each = 5)
    )

    # Test with two dataframes
    result <- add_group_id(df1, df2, by = c("category", "type"))
    expect_equal(names(result), c("x", "y"))
    expect_equal(
      unique(result$x[order(result$x$g_id), c("g_id", "category", "type")]),
      unique(result$y[order(result$y$g_id), c("g_id", "category", "type")])
    )

    # Test automatic categorical variable detection
    result_auto <- add_group_id(df1, df2)
    expect_equal(
      unique(result_auto$x[order(result_auto$x$g_id), c("g_id", "category", "type")]),
      unique(result_auto$y[order(result_auto$y$g_id), c("g_id", "category", "type")])
    )

    # Test error handling
    expect_error(add_group_id(df1, df2, by = "nonexistent"))
  })

  test_that("keys_match works", {
  # Test data
  x <- data.frame(
    type = c("1", "2"),
    category = c("a", "b"),
    scenario_id = c(0, 1)
  )

  y <- data.frame(
    type = c("1", "2"),
    category = c("c", "d"),
    scenario_id = c(0, 2)
  )

  # Automatic matching
  expect_message(
    result <- keys_match(x, y),
    "Group by: type, category"
  )

  expect_equal(result$xy$scenario_id, c(0, 1, 0, 2))

  # Match by type
  result_type <- keys_match(x, y, "type")
  expect_equal(result_type$xy$g_id, c(1, 2, 2))
  })


})