tests/testthat/test-group-size.R

In sctyner/dplyr050: A Grammar of Data Manipulation

context("Group sizes")

df <- data.frame(x = rep(1:3, each = 10), y = rep(1:6, each = 5))
tbls <- test_load(df)

test_that("ungrouped data has 1 group, with group size = nrow()", {
  for (tbl in tbls) {
    expect_equal(n_groups(tbl), 1L)
    expect_equal(group_size(tbl), 30)
  }
})

test_that("rowwise data has one group for each group", {
  rw <- rowwise(df)
  expect_equal(n_groups(rw), 30)
  expect_equal(group_size(rw), rep(1, 30))
})

test_that("group_size correct for grouped data", {
  for (tbl in tbls) {
    grp <- group_by(tbl, x)
    expect_equal(n_groups(grp), 3L)
    expect_equal(group_size(grp), rep(10, 3))
  }
})