tests/testthat/test_piest.r

In joemckean/mathstat: Introduction to Mathematical Statistics R Package

context("piest.r")

six_decimal_error <- 1e-07

# Test invalid inputs.
test_that("input", {
  expect_error(piest("x"), "argument 1 must be a number")
  expect_error(piest(c(1, 2, 3)), "argument 1 cannot have length greater than 1")
  expect_error(piest(Inf), "argument 1 cannot include an Inf or -Inf")
  expect_error(piest(NaN), "argument 1 cannot include a NaN")
  expect_error(piest(-1), "argument 1 must be positive")
  expect_error(piest(0), "argument 1 must be numeric and non-zero")
})

# Test valid inputs expecting valid results.
test_that("n=3", {
  result <- piest(3)
  
  expect_that(result, is_a("list"))
  expect_that(length(result), equals(2))
  expect_that(result$estimate >= 0, is_true())
  expect_that(result$standard_error >= 0, is_true())
})

test_that("n=5000", {
  result <- piest(5000)
  expect_that(result, is_a("list"))
  expect_that(length(result), equals(2))
  expect_that(abs(3.14 - result$estimate) < 0.1, is_true())
  expect_that(result$standard_error < 0.1, is_true())
})


# Test valid input which results in invalid result.
test_that("n=5000000000", {
  expect_that(piest(5e+09), throws_error("cannot allocate vector"))
})