Add a test for set_at and fix it

Author: victor-Lopez25

Inc/HALAL/Services/Time/Scheduler.hpp

@@ -101,9 +101,9 @@ struct Scheduler {
         return (uint8_t)((sorted_task_ids_ >> (idx * 4)) & 0xF);
     }
     static HYPER_INLINE void set_at(uint8_t idx, uint8_t id) {
-        uint32_t shift = idx * 4;
-        uint64_t clearmask = ~(0xFFULL << shift);
-        Scheduler::sorted_task_ids_ = (sorted_task_ids_ & clearmask) | (id << shift);
+        uint64_t shift = idx * 4;
+        uint64_t clearmask = ~(0x0FULL << shift);
+        Scheduler::sorted_task_ids_ = (sorted_task_ids_ & clearmask) | ((uint64_t)id << shift);
     }
     static HYPER_INLINE uint8_t front_id() { return *((uint8_t*)&sorted_task_ids_) & 0xF; }
     static HYPER_INLINE void pop_front() {

Tests/Time/scheduler_test.cpp

@@ -40,6 +40,15 @@ TEST_F(SchedulerTests, GetAt) {
     }
 }
 
+TEST_F(SchedulerTests, SetAt) {
+    uint64_t original = 0x1EDCBA9876543210ULL;
+    for (uint64_t i = 0; i < 16; i++) {
+        Scheduler::sorted_task_ids_ = original;
+        Scheduler::set_at(i, 0xF);
+        EXPECT_EQ(Scheduler::sorted_task_ids_, original | (0xFULL << (i*4)));
+    }
+}
+
 TEST_F(SchedulerTests, FreeBitmap) {
     Scheduler::register_task(10, &fake_workload);
     EXPECT_EQ(Scheduler::free_bitmap_, 0xFFFF'FFFE);