fix: check type of column roles (#1131)

* fix: check type of column roles

* repair checks for tasks with arbitrary row ids

---------

Co-authored-by: Michel Lang <michellang@gmail.com>

R/Task.R

@@ -1195,6 +1195,20 @@ task_check_col_roles = function(self, new_roles) {
     }
   }
 
+  # check weights
+  if (length(new_roles[["weight"]])) {
+    weights = self$backend$data(self$backend$rownames, cols = new_roles[["weight"]])
+    assert_numeric(weights[[1L]], lower = 0, any.missing = FALSE, .var.name = names(weights))
+  }
+
+  # check name
+  if (length(new_roles[["name"]])) {
+    row_names = self$backend$data(self$backend$rownames, cols = new_roles[["name"]])
+    if (!is.character(row_names[[1L]]) && !is.factor(row_names[[1L]])) {
+      stopf("Assertion on '%s' failed: Must be of type 'character' or 'factor', not %s", names(row_names), class(row_names[[1]]))
+    }
+  }
+
   if (inherits(self, "TaskSupervised")) {
     if (length(new_roles$target) == 0L) {
       stopf("Supervised tasks need at least one target column")

tests/testthat/test_Task.R

@@ -283,6 +283,25 @@ test_that("groups/weights work", {
   }, "up to one")
 })
 
+test_that("col roles are valid", {
+  b = as_data_backend(data.table(
+    y = runif(20),
+    logical = sample(c(TRUE, FALSE), 20, replace = TRUE),
+    numeric = runif(20),
+    integer = sample(1:3, 20, replace = TRUE),
+    factor = factor(sample(letters[1:3], 20, replace = TRUE))))
+  task = TaskRegr$new("test", b, target = "y")
+
+  # weight
+  expect_error(task$set_col_roles("logical", roles = "weight"), "type")
+  expect_error(task$set_col_roles("factor", roles = "weight"), "type")
+
+  # name
+  expect_error(task$set_col_roles("logical", roles = "name"), "type")
+  expect_error(task$set_col_roles("integer", roles = "name"), "type")
+  expect_error(task$set_col_roles("numeric", roles = "name"), "type")
+})
+
 test_that("ordered factors (#95)", {
   df = data.frame(
     x = c(1, 2, 3),