context("checkFunction")

test_that("checkFunction", {
  myobj = mean
  expect_succ_all(Function, myobj)
  myobj = TRUE
  expect_fail_all(Function, myobj)

  myfun = function(x, y, ...) x + y

  expect_false(testFunction(NULL))
  expect_true(testFunction(identity))
  expect_true(testFunction(myfun))
  expect_false(testFunction("myfun"))
  expect_false(testFunction("myfun"))

  expect_true(testFunction(myfun, args = "x"))
  expect_true(testFunction(myfun, args = "..."))
  expect_true(testFunction(myfun, args = "x", ordered = TRUE))
  expect_true(testFunction(myfun, args = "y"))
  expect_true(testFunction(myfun, args = c("x", "y")))
  expect_true(testFunction(myfun, args = c("x", "y", "...")))
  expect_true(testFunction(myfun, args = c("y", "x")))
  expect_true(testFunction(myfun, args = c("x", "y"), ordered = TRUE))
  expect_false(testFunction(myfun, args = "z"))
  expect_false(testFunction(myfun, args = c("y"), ordered = TRUE))
  expect_false(testFunction(myfun, args = c("y", "x"), ordered = TRUE))

  expect_true(testFunction(myfun, nargs = 2))
  expect_true(testFunction(myfun, args = "x", nargs = 2))
  expect_true(testFunction(function() 1, nargs = 0))
  expect_true(testFunction(function(...) 1, nargs = 0))
  expect_false(testFunction(function(...) 1, nargs = 1))

  expect_error(assertFunction(fff), "not found")
  expect_error(assertFunction(myfun, "z"), "formal arguments")
  expect_error(assertFunction(myfun, "y", ordered=TRUE), "first formal arguments")

  expect_false(testFunction(function(x) x^2, args = character(0)))
  expect_true(testFunction(function() x^2, args = character(0)))
  expect_error(assertFunction(letters), "character")
})

test_that("checkFunction with Primitives", {
  expect_true(testFunction(sqrt))
  expect_true(testFunction(sqrt, args = "x"))
  expect_true(testFunction(as.logical, nargs = 1)) # bug 144
})

test_that("ordered and no args (#204)", {
  f = function() 0
  expect_error(assertFunction(f, args = c("a", "b"), ordered = FALSE), "formal arguments")
  expect_error(assertFunction(f, args = c("a", "b"), ordered = TRUE), "formal arguments")
})