# group_data --------------------------------------------------------------

test_that("group_data(<data.frame>) returns a data frame", {
  df <- data.frame(x = 1:3)
  gd <- group_data(df)

  expect_s3_class(gd, "data.frame", exact = TRUE)
  expect_equal(gd$.rows, list_of(1:3))
})

test_that("group_data(<tbl_df>) returns a tibble", {
  df <- tibble(x = 1:3)
  gd <- group_data(df)

  expect_s3_class(gd, "tbl_df")
  expect_equal(gd, tibble(".rows" := list_of(1:3)))
})

test_that("group_data(<grouped_df>) returns a tibble", {
  df <- tibble(x = c(1, 1, 2))
  gf <- group_by(df, x)
  gd <- group_data(gf)

  expect_s3_class(gd, "tbl_df")
  expect_equal(
    gd,
    tibble(x = c(1, 2), ".rows" := list_of(1:2, 3L)),
    ignore_attr = TRUE
  )
})

test_that("group_data(<rowwise) returns a tibble", {
  df <- tibble(x = 1:3)
  rf <- rowwise(df)
  gd <- group_data(rf)

  expect_s3_class(gd, "tbl_df")
  expect_equal(gd, tibble(".rows" := list_of(1, 2, 3)))
})

# group_rows() and group_keys() -------------------------------------------

test_that("group_rows() and group_keys() partition group_data()", {
  df <- data.frame(x = 1:2, y = 1:2)
  gf <- group_by(df, x, y)
  gd <- group_data(gf)

  expect_equal(group_keys(gf), gd[1:2], ignore_attr = TRUE) # .drop attribute
  expect_equal(group_rows(gf), gd[[3]])
})

test_that("group_keys(...) is defunct", {
  df <- tibble(x = 1, y = 2)

  expect_snapshot(error = TRUE, {
    group_keys(df, x)
  })
})

# group_indices() ---------------------------------------------------------

test_that("no arg group_indices() is deprecated", {
  df <- tibble(x = 1)

  expect_snapshot({
    out <- summarise(df, id = group_indices())
  })

  expect_equal(out, tibble(id = 1))
})

test_that("group_indices(...) is deprecated", {
  df <- tibble(x = 1, y = 2)

  expect_snapshot(error = TRUE, {
    group_indices(df, x)
  })
})

test_that("group_indices() returns expected values", {
  df <- tibble(x = c("b", "a", "b"))
  gf <- group_by(df, x)

  expect_equal(group_indices(df), c(1, 1, 1))
  expect_equal(group_indices(gf), c(2, 1, 2))
})

test_that("group_indices() handles 0 rows data frames (#5541)", {
  df <- new_grouped_df(
    data.frame(x = integer(), y = integer()),
    groups = data.frame(x = 0, .rows = vctrs::list_of(1:1000))
  )
  expect_equal(group_indices(df), integer())
})

# group_size --------------------------------------------------------------

test_that("ungrouped data has 1 group, with group size = nrow()", {
  df <- tibble(x = rep(1:3, each = 10), y = rep(1:6, each = 5))

  expect_equal(n_groups(df), 1L)
  expect_equal(group_size(df), 30)
})

test_that("rowwise data has one group for each group", {
  rw <- rowwise(mtcars)
  expect_equal(n_groups(rw), 32)
  expect_equal(group_size(rw), rep(1, 32))
})

test_that("group_size correct for grouped data", {
  df <- tibble(x = rep(1:3, each = 10), y = rep(1:6, each = 5)) |> group_by(x)
  expect_equal(n_groups(df), 3L)
  expect_equal(group_size(df), rep(10, 3))
})

# n_groups ----------------------------------------------------------------

test_that("n_groups respects zero-length groups (#341)", {
  df <- tibble(x = factor(1:3, levels = 1:4)) |> group_by(x, .drop = FALSE)
  expect_equal(n_groups(df), 4)
})