test_that("measurement class works", {
  expect_true(S7::S7_inherits(measurement))

  expect_true(S7::S7_inherits(measurement(), measurement))
  expect_true(S7::S7_inherits(lcdm(), measurement))
  expect_true(S7::S7_inherits(dina(), measurement))
  expect_true(S7::S7_inherits(dino(), measurement))
  expect_true(S7::S7_inherits(crum(), measurement))
  expect_true(S7::S7_inherits(nida(), measurement))
  expect_true(S7::S7_inherits(nido(), measurement))
  expect_true(S7::S7_inherits(ncrum(), measurement))

  expect_true(S7::S7_inherits(lcdm(), LCDM))
  expect_true(S7::S7_inherits(dina(), DINA))
  expect_true(S7::S7_inherits(dino(), DINO))
  expect_true(S7::S7_inherits(crum(), CRUM))
  expect_true(S7::S7_inherits(nida(), NIDA))
  expect_true(S7::S7_inherits(nido(), NIDO))
  expect_true(S7::S7_inherits(ncrum(), NCRUM))
})

test_that("measurment class errors", {
  expect_error(
    measurement(
      model = "taylor"
    ),
    "@model must be one of"
  )

  expect_error(
    measurement(
      model = "lcdm",
      model_args = list(taylor = 13)
    ),
    "@model_args contains unknown arguments"
  )
})

test_that("structural class works", {
  expect_true(S7::S7_inherits(structural))

  expect_true(S7::S7_inherits(structural(), structural))
  expect_true(S7::S7_inherits(unconstrained(), structural))
  expect_true(S7::S7_inherits(independent(), structural))
  expect_true(S7::S7_inherits(loglinear(), structural))
  expect_true(S7::S7_inherits(hdcm(), structural))
  expect_true(S7::S7_inherits(bayesnet(), structural))

  expect_true(S7::S7_inherits(unconstrained(), UNCONSTRAINED))
  expect_true(S7::S7_inherits(independent(), INDEPENDENT))
  expect_true(S7::S7_inherits(loglinear(), LOGLINEAR))
  expect_true(S7::S7_inherits(hdcm(), HDCM))
  expect_true(S7::S7_inherits(bayesnet(), BAYESNET))
})

test_that("structural class errors", {
  expect_error(
    structural(
      model = "travis"
    ),
    "@model must be one of"
  )

  expect_error(
    structural(
      model = "hdcm",
      model_args = list(travis = 87)
    ),
    "@model_args contains unknown arguments"
  )
})

test_that("quantities class works", {
  expect_true(S7::S7_inherits(quantities))

  expect_true(S7::S7_inherits(quantities(), quantities))
  expect_true(S7::S7_inherits(generated_quantities(), quantities))

  expect_true(S7::S7_inherits(generated_quantities(), GQS))
})

test_that("quantities class errors", {
  expect_error(
    quantities(model_args = list(taylor = 13)),
    "@model_args contains unknown arguments"
  )
})

test_that("model_property cannot be overwritten", {
  meas_mod <- lcdm()
  expect_error(
    meas_mod@model <- "dina",
    "@model is read-only"
  )

  strc_mod <- loglinear()
  expect_error(
    strc_mod@model <- "hdcm",
    "@model is read-only"
  )
})