# Exits
if (!requireNamespace("mlr3", quietly = TRUE)) {
  exit_file("Package 'mlr3' missing")
}
if (!requireNamespace("mlr3learners", quietly = TRUE)) {
  exit_file("Package 'mlr3learners' missing")
}
if (!requireNamespace("ranger", quietly = TRUE)) {
  exit_file("Package 'ranger' missing")
}

# Load required packages
#suppressMessages({
#  library(mlr3)
#  library(mlr3learners)
#  library(ranger)
#})

# Generate Friedman benchmark data
friedman1 <- gen_friedman(seed = 101)

# Fit model(s)
set.seed(101)
task <- mlr3::TaskRegr$new("friedman", backend = friedman1, target = "y")
lrnr <- mlr3::lrn("regr.ranger", importance = "impurity")
expect_error(vi(lrnr))  # did not call `$traini()` yet
expect_error(vi_model(lrnr))  # did not call `$traini()` yet
lrnr$train(task)  # `vi()`, etc. should now work

# Compute model-based VI scores
vis <- vi_model(lrnr)

# Expect `vi()` and `vi_model()` to both work
expect_identical(
  current = vi(lrnr, sort = FALSE),
  target = vi_model(lrnr)
)

# Expectations for `vi_model()`
expect_identical(
  current = vis$Importance,
  target = unname(lrnr$model$variable.importance)
)

# Expectations for `get_feature_names()`
expect_identical(
  current = sort(vip:::get_feature_names.Learner(lrnr)),
  target = sort(paste0("x", 1L:10L))
)
