test_that("zero diagonal etas must have zero off-diagonals (rxode2#481)", {

  expect_error(
    lotri({
      lka <- 0.45
      lcl <- 1
      lvc <- 3.45
      propSd <- fix(0)
      etalcl + etalvc ~ c(0, 0.05, 0)
    }, cov=FALSE),
    NA)

  expect_error(
    lotri({
      lka <- 0.45
      lcl <- 1
      lvc <- 3.45
      propSd <- fix(0)
      etalcl + etalvc ~ c(0, 0.05, 0)
    }, cov=TRUE),
    regexp = "if diagonals are zero, off-diagonals must be zero for covariance matrices (row 1, column 2)",
    fixed = TRUE)

  expect_error(
    lotri({
      lka <- 0.45
      lcl <- 1
      lvc <- 3.45
      propSd <- fix(0)
      etalcl + etalvc ~ c(1, 0.05, 0)
    }, cov=TRUE),
    regexp = "if diagonals are zero, off-diagonals must be zero for covariance matrices (row 2, column 1)",
    fixed = TRUE)

  expect_error(
    lotri({
      lka <- 0.45
      lcl <- 1
      lvc <- 3.45
      propSd <- fix(0)
      etalcl + etalvc ~ c(1, 0.05, 0)
    }, cov=FALSE),
    NA)

  expect_error(
    lotri({
      lka <- 0.45
      lcl <- 1
      lvc <- 3.45
      propSd <- fix(0)
      etalcl + etalvc ~ c(0, 0.05, 1)
    }, cov=TRUE),
    regexp = "if diagonals are zero, off-diagonals must be zero for covariance matrices (row 1, column 2)",
    fixed = TRUE
  )

  expect_error(
    lotri({
      lka <- 0.45
      lcl <- 1
      lvc <- 3.45
      propSd <- fix(0)
      etalcl + etalvc ~ c(0, 0.05, 1)
    }, cov=FALSE),
    NA)

  # call out non-id levels
  expect_error(
    lotri({
      lka <- 0.45
      lcl <- 1
      lvc <- 3.45
      propSd <- fix(0)
      etalcl + etalvc ~ c(0, 0.05, 0) | occ
    }, cov=TRUE),
    regexp="if diagonals are zero, off-diagonals must be zero for covariance matrices (row 1, column 2, level occ)",
    fixed=TRUE
  )


})