test_that("agent()<- assignment works", {
  p1 <- person(given = "Jane", family = "Doe", role = c("cre", "aut"))
  p2 <- person(given = "Joe", family = "Doe", role = c("aut", "dtm"))
  p3 <- person(given = "Publisher Inc", role = c("pbl"))
  test_df <- dataset_df(data.frame(a = 1, b = 2))
  expect_error(agent(test_df) <- 1:2,
    regexp = "value must be a vector of utils\\:\\:persons\\(\\) class"
  )
  expect_equal(get_bibentry(test_df)$author, person("Author", "Unknown"))
  expect_error(agent(x = 1) <- person("Jane Doe"))
})

test_that("agent() works", {
  expect_error(agent(x = 1:3),
    regexp = "x must be a dataset_df, a vector of persons, a dublincore or datacite object"
  )
  p1 <- person("Jane", "Doe", role = c("cre", "aut"))
  p2 <- person("Joe", "Doe", role = c("aut", "dtm"))
  p3 <- person("Publisher Inc", role = c("pbl"))
  expect_equal(length(agent(x = c(p1, p2, p3))), 3)
  expect_equal(
    agent(x = c(p1, p2, p3))$creators[1],
    person("Jane", "Doe", role = c("cre", "aut"))
  )
  expect_null(agent(x = c(p1, p2, p3))$contributors)
  expect_equal(
    agent(x = c(p1, p2, p3))$publisher,
    person("Publisher Inc", role = c("pbl"))
  )
})