test_that("Array input throws no errors", {
  A = array(rnorm(108*2), c(108,2))
  B = array(rnorm(100*2), c(100,2))
  C = array(rnorm(10*2), c(10,2))
  X = reinflateTensor(A, B, C, returnAsTensor=FALSE)
  expect_no_error(parafac(X, 2, maxit=2))
})

test_that("Tensor input throws no errors", {
  A = array(rnorm(108*2), c(108,2))
  B = array(rnorm(100*2), c(100,2))
  C = array(rnorm(10*2), c(10,2))
  X = reinflateTensor(A, B, C, returnAsTensor=TRUE)
  expect_no_error(parafac(X, 2, maxit=2))
})

test_that("Xhat has the right dimensions", {
  A = array(rnorm(108*2), c(108,2))
  B = array(rnorm(100*2), c(100,2))
  C = array(rnorm(10*2), c(10,2))
  X = reinflateTensor(A, B, C, returnAsTensor=TRUE)
  model = parafac(X, 2, maxit=2)
  expect_equal(dim(model$Xhat), c(108,100,10))
})

test_that("Number of iterations is more than 1", {
  A = array(rnorm(108*2), c(108,2))
  B = array(rnorm(100*2), c(100,2))
  C = array(rnorm(10*2), c(10,2))
  X = reinflateTensor(A, B, C, returnAsTensor=TRUE)
  model = parafac(X, 2, maxit=20)
  expect_gt(model$iter, 1)
})

test_that("SSE is larger than 0", {
  A = array(rnorm(108*2), c(108,2))
  B = array(rnorm(100*2), c(100,2))
  C = array(rnorm(10*2), c(10,2))
  X = reinflateTensor(A, B, C, returnAsTensor=TRUE)
  model = parafac(X, 2, maxit=2)
  expect_gt(model$SSE, 0)
})

test_that("Varexp is greater than 0", {
  A = array(rnorm(108*2), c(108,2))
  B = array(rnorm(100*2), c(100,2))
  C = array(rnorm(10*2), c(10,2))
  X = reinflateTensor(A, B, C, returnAsTensor=TRUE)
  model = parafac(X, 2, maxit=2)
  expect_gt(model$varExp, 0)
})

test_that("Varexp is smaller than or equal to 100", {
  A = array(rnorm(108*2), c(108,2))
  B = array(rnorm(100*2), c(100,2))
  C = array(rnorm(10*2), c(10,2))
  X = reinflateTensor(A, B, C, returnAsTensor=TRUE)
  model = parafac(X, 2, maxit=20)
  expect_true(model$varExp <= 100.01)
})

test_that("nstart larger than 1 returns nstart models if output is all", {
  A = array(rnorm(108*2), c(108,2))
  B = array(rnorm(100*2), c(100,2))
  C = array(rnorm(10*2), c(10,2))
  X = reinflateTensor(A, B, C, returnAsTensor=TRUE)
  models = parafac(X, 2, nstart=10, output="all", maxit=2)
  expect_equal(length(models), 10)
})