## Tests for response model functions

## Load packages
library("testthat")
library("coenocliner")

n <- 10L

test_that("NegBin returns the right number of random draws", {
  expect_identical(length(NegBin(n, mu = 2, alpha = 1)), n)
})

test_that("Poisson returns the right number of random draws", {
  expect_identical(length(Poisson(n, mu = 2)), n)
})

test_that("Bernoulli returns the right number of random draws", {
  expect_identical(length(Bernoulli(n, mu = 0.5)), n)
})

test_that("Binomial returns the right number of random draws", {
  expect_identical(length(Binomial(n, mu = 0.5, size = 10)), n)
})

test_that("BetaBinomial returns the right number of random draws", {
  expect_identical(length(BetaBinomial(n, mu = 0.5, size = 10,
                                       theta = 2)), n)
})

test_that("ZIP returns the right number of random draws", {
  expect_identical(length(ZIP(n, mu = 2, zprobs = 0.5)), n)
})

test_that("ZINB returns the right number of random draws", {
  expect_identical(length(ZINB(n, mu = 2, alpha = 1, zprobs = 0.5)), n)
})

test_that("ZIB returns the right number of random draws", {
  expect_identical(length(ZIB(n, mu = 0.5, size = 10, zprobs = 0.5)), n)
})

test_that("ZIBB returns the right number of random draws", {
  expect_identical(length(ZIBB(n, mu = 0.5, size = 10,
                               theta = 2, zprobs = 0.5)), n)
})

test_that("NegBin handles negative alpha correctly", {
  expect_error(NegBin(n, mu = 2, alpha = -1),
               regexp = "Negative values of 'alpha' are not supported")
})

test_that("NegBin returns same as Poisson for alpha = 0", {
  mu <- 2
  set.seed(1)
  rnd1 <- NegBin(n, mu = mu, alpha = 0)
  set.seed(1)
  rnd2 <- Poisson(n, mu = mu)
  expect_identical(rnd1, rnd2)
})

test_that("ZINB handles negative alpha correctly", {
    expect_error(ZINB(n, mu = 2, alpha = -1, zprobs = 0.2),
                 regexp = "Negative values of 'alpha' are not supported")
})

test_that("ZINB returns same as ZIP for alpha = 0", {
  mu <- 2
  zprobs <- 0.2
  set.seed(1)
  rnd1 <- ZINB(n, mu = mu, alpha = 0, zprobs = zprobs)
  set.seed(1)
  rnd2 <- ZIP(n, mu = mu, zprobs = zprobs)
  expect_identical(rnd1, rnd2)
})

test_that("NegBin and ZINB work with vector alpha argument", {
  mu <- 2
  zprobs <- 0.2
  set.seed(1)
  rndNegBin <- NegBin(n, mu = mu, alpha = 0)
  rndZINB   <- ZINB(n, mu = mu, alpha = 0, zprobs = zprobs)
  expect_type(rndNegBin, "integer")
  expect_length(rndNegBin, 10L)
  expect_type(rndZINB, "integer")
  expect_length(rndZINB, 10L)
})