Test error handling

inst/include/dust2/r/helpers.hpp

@@ -87,8 +87,7 @@ bool is_integer_like(T x, T eps) {
   return std::abs(x - std::round(x)) <= eps;
 }
 
-template <typename T>
-cpp11::integers as_integers(cpp11::doubles x, const char * name) {
+inline cpp11::integers as_integers(cpp11::doubles x, const char * name) {
   const auto len = x.size();
   cpp11::writable::integers ret(x.size());
   for (auto i = 0; i < len; ++i) {
@@ -156,7 +155,8 @@ inline std::vector<size_t> check_index(cpp11::sexp r_index, size_t max,
     return ret;
   }
   if (TYPEOF(r_index) == REALSXP) {
-    return check_index(as_integers(r_index), max, name);
+    cpp11::doubles r_index_real = cpp11::as_cpp<cpp11::doubles>(r_index);
+    return check_index(as_integers(r_index_real, name), max, name);
   }
   if (TYPEOF(r_index) != INTSXP) {
     cpp11::stop("Expected an integer vector for '%s'", name);

tests/testthat/test-walk.R

@@ -444,7 +444,32 @@ test_that("can simulate walk model with index", {
   ptr1 <- obj1[[1]]
   ptr2 <- obj2[[1]]
 
-  res1 <- dust2_cpu_walk_simulate(ptr1, 0:20, c(2L, 4L), TRUE)
+  res1 <- dust2_cpu_walk_simulate(ptr1, 0:20, c(2, 4), TRUE)
   res2 <- dust2_cpu_walk_simulate(ptr2, 0:20, NULL, TRUE)
   expect_equal(res1, res2[c(2, 4), , , ])
 })
+
+
+test_that("can validate index values", {
+  pars <- list(len = 3, sd = 1)
+  obj <- dust2_cpu_walk_alloc(pars, 0, 1, 10, 0, 42, FALSE)
+  ptr <- obj[[1]]
+  expect_error(
+    dust2_cpu_walk_simulate(ptr, 0:20, c("2", "4"), TRUE),
+    "Expected an integer vector for 'index'")
+  expect_error(
+    dust2_cpu_walk_simulate(ptr, 0:20, c(2, 2.9), TRUE),
+    "All values of 'index' must be integer-like, but 'index[2]' was not",
+    fixed = TRUE)
+  expect_error(
+    dust2_cpu_walk_simulate(ptr, 0:20, c(2, 20), TRUE),
+    "All values of 'index' must be in [1, 3], but 'index[2]' was 20",
+    fixed = TRUE)
+  expect_error(
+    dust2_cpu_walk_simulate(ptr, 0:20, c(2, 3, -4), TRUE),
+    "All values of 'index' must be in [1, 3], but 'index[3]' was -4",
+    fixed = TRUE)
+  expect_error(
+    dust2_cpu_walk_simulate(ptr, 0:20, integer(), TRUE),
+    "'index' must have nonzero length")
+})