tests/testthat/test-cast-obj.R

In causalDisco: Tools for Causal Discovery on Observational Data

# ──────────────────────────────────────────────────────────────────────────────
# cast_obj()
# ──────────────────────────────────────────────────────────────────────────────

test_that("cast_obj() casts ScoreWrapper implementors", {
  skip_if_no_tetrad()

  # Try common score wrappers; use whichever is available
  score <- try(
    rJava::.jnew("edu/cmu/tetrad/algcomparison/score/SemBicScore"),
    silent = TRUE
  )
  if (inherits(score, "try-error")) {
    score <- try(
      rJava::.jnew("edu/cmu/tetrad/algcomparison/score/BDeuScore"),
      silent = TRUE
    )
  }
  if (inherits(score, "try-error")) {
    skip(
      "No ScoreWrapper implementation available on classpath (SemBicScore/BDeuScore)."
    )
  }

  out <- cast_obj(score)
  expect_true(
    rJava::.jinstanceof(out, "edu/cmu/tetrad/algcomparison/score/ScoreWrapper")
  )
})

test_that("cast_obj() casts DataModel (DataSet)", {
  skip_if_no_tetrad()

  my_df <- data.frame(x = c(1.0, NA_real_), y = factor(c(1L, 2L)))
  ds <- rdata_to_tetrad(my_df)

  out <- cast_obj(ds)
  expect_true(rJava::.jinstanceof(out, "edu/cmu/tetrad/data/DataModel"))
})

test_that("cast_obj() casts IndependenceWrapper implementors", {
  skip_if_no_tetrad()

  # FisherZ is a common wrapper with a no-arg ctor in algcomparison
  indep <- try(
    rJava::.jnew("edu/cmu/tetrad/algcomparison/independence/FisherZ"),
    silent = TRUE
  )
  if (inherits(indep, "try-error")) {
    skip(
      "No IndependenceWrapper implementation available on classpath (FisherZ)."
    )
  }

  out <- cast_obj(indep)
  expect_true(
    rJava::.jinstanceof(
      out,
      "edu/cmu/tetrad/algcomparison/independence/IndependenceWrapper"
    )
  )
})

test_that("cast_obj() casts Graph implementors (EdgeListGraph)", {
  skip_if_no_tetrad()

  # EdgeListGraph usually has a no-arg constructor
  graph <- try(
    rJava::.jnew("edu/cmu/tetrad/graph/EdgeListGraph"),
    silent = TRUE
  )
  if (inherits(graph, "try-error")) {
    skip(
      "EdgeListGraph not available or lacks no-arg constructor on this Tetrad build."
    )
  }

  out <- cast_obj(graph)
  expect_true(rJava::.jinstanceof(out, "edu/cmu/tetrad/graph/Graph"))
})

test_that("cast_obj() errors on unsupported Java objects", {
  skip_if_no_tetrad()

  s <- rJava::.jnew("java/lang/String", "nope")
  expect_error(
    cast_obj(s),
    "The Java object cannot be cast to a superclass by cast_obj."
  )
})