test_that("crate() supports lambda syntax", {
  expect_equal(
    crate(~NULL),
    new_crate(as_function(~NULL, env = current_env())),
    ignore_function_env = TRUE
  )
})

test_that("crate() requires named `...` arguments", {
  expect_snapshot(
    error = TRUE,
    crate(function(x) identity(x), x = 1, y = 2, 3),
  )
  expect_no_error(crate(function(x) identity(x), x = 1, y = 2))
  expect_no_error(crate(function(x) identity(x)))
})

test_that("crate() requires functions", {
  expect_snapshot(error = TRUE, crate(1))
})

test_that("crate() supports quasiquotation", {
  foo <- "foo"

  fn <- crate(function() toupper(!!foo))
  expect_identical(body(fn), quote(toupper("foo")))
  expect_identical(fn(), "FOO")

  fn <- crate(~ toupper(!!foo))
  expect_identical(body(fn), quote(toupper("foo")))
  expect_identical(fn(), "FOO")
})

test_that("can supply data", {
  fn <- crate(~ toupper(foo), foo = "foo")
  expect_identical(fn(), "FOO")

  foo <- "foo"
  fn <- crate(~ toupper(foo), foo = foo)
  expect_identical(fn(), "FOO")
})

test_that("can supply data before or after function", {
  foo <- "foo"
  fn <- crate(foo = foo, ~ toupper(foo))
  expect_identical(fn(), "FOO")
})

test_that("fails if relevant data not supplied", {
  foobar <- "foobar"
  fn <- crate(foo = "foo", ~ toupper(foobar))
  expect_error(fn(), "not found")
})

test_that("can supply data in a block", {
  fn <- crate({
    foo <- "foo"
    bar <- "bar"
    ~ paste(foo, bar)
  })

  expect_data(fn, "foo", "bar")
})

test_that("crated function roundtrips under serialisation", {
  fn <- crate(~ toupper(foo), foo = "foo")
  out <- unserialize(serialize(fn, NULL))
  expect_equal(as.list(fn_env(fn)), as.list(fn_env(out)))
  expect_equal(fn(), out())
})

test_that("new_crate() requires functions", {
  expect_snapshot(error = TRUE, new_crate(1))
  expect_snapshot(error = TRUE, new_crate(~foo))
})

test_that("new_crate() crates", {
  expect_s3_class(new_crate(function() NULL), "crate")
})

test_that("sizes are printed with the crate", {
  foo <- "foo"
  bar <- 1:100
  fn <- crate(~NULL, foo = foo, bar = bar)

  bare_fn <- fn
  attributes(bare_fn) <- NULL
  environment(bare_fn) <- global_env()

  bare_size <- format_bytes(lobstr::obj_size(bare_fn))
  bar_size <- format_bytes(lobstr::obj_size(bar))
  foo_size <- format_bytes(lobstr::obj_size(foo))

  output <- "
* function: %s
* `bar`: %s
* `foo`: %s"
  output <- sprintf(output, bare_size, bar_size, foo_size)

  expect_output(print(fn), output, fixed = TRUE)
})

test_that("empty crates are printed correctly", {
  fn <- crate(~NULL)

  bare_fn <- fn
  attributes(bare_fn) <- NULL
  environment(bare_fn) <- global_env()

  bare_size <- format_bytes(lobstr::obj_size(bare_fn))

  output <- "
* function: %s
function"
  output <- sprintf(output, bare_size)

  expect_output(print(fn), output, fixed = TRUE)
})

test_that("function must be defined in the crate environment", {
  fn <- function() NULL
  expect_snapshot(error = TRUE, crate(fn))

  expect_s3_class(crate(set_env(fn)), "crate")
})