adds schedule test

Author: sunny-g

rustler_tests/lib/rustler_test.ex

@@ -74,6 +74,8 @@ defmodule RustlerTest do
 
   def sum_range(_), do: err()
 
+  def scheduled_fac(_, _ \\ nil), do: err()
+
   def bad_arg_error(), do: err()
   def atom_str_error(), do: err()
   def raise_atom_error(), do: err()

rustler_tests/native/rustler_test/src/lib.rs

@@ -10,6 +10,7 @@ mod test_nif_attrs;
 mod test_primitives;
 mod test_range;
 mod test_resource;
+mod test_schedule;
 mod test_term;
 mod test_thread;
 
@@ -65,6 +66,7 @@ rustler::init!(
         test_codegen::tuplestruct_record_echo,
         test_dirty::dirty_cpu,
         test_dirty::dirty_io,
+        test_schedule::scheduled_fac,
         test_range::sum_range,
         test_error::bad_arg_error,
         test_error::atom_str_error,

rustler_tests/native/rustler_test/src/test_schedule.rs

@@ -0,0 +1,11 @@
+use rustler::schedule::Schedule;
+
+#[rustler::nif]
+fn scheduled_fac(input: u32, result: Option<u32>) -> Schedule<scheduled_fac, u32, u32, u32> {
+    let result = result.unwrap_or(1);
+    if input == 0 {
+        Schedule::Result(result)
+    } else {
+        Schedule::next2(input - 1, result * input)
+    }
+}

rustler_tests/test/schedule_test.exs

@@ -0,0 +1,7 @@
+defmodule RustlerTest.ScheduleTest do
+  use ExUnit.Case, async: true
+
+  test "scheduled factorial" do
+    assert 24 == RustlerTest.scheduled_fac(4)
+  end
+end