Add (failing) skip slots tests

beacon_node/http_api/tests/tests.rs

@@ -185,6 +185,16 @@ impl ApiTester {
         }
     }
 
+    fn skip_slots(self, count: u64) -> Self {
+        for _ in 0..count {
+            self.chain
+                .slot_clock
+                .set_slot(self.chain.slot().unwrap().as_u64() + 1);
+        }
+
+        self
+    }
+
     fn interesting_state_ids(&self) -> Vec<StateId> {
         let mut ids = vec![
             StateId::Head,
@@ -1644,11 +1654,27 @@ async fn get_validator_duties_attester() {
     ApiTester::new().test_get_validator_duties_attester().await;
 }
 
+#[tokio::test(core_threads = 2)]
+async fn get_validator_duties_attester_with_skip_slots() {
+    ApiTester::new()
+        .skip_slots(E::slots_per_epoch() * 2)
+        .test_get_validator_duties_attester()
+        .await;
+}
+
 #[tokio::test(core_threads = 2)]
 async fn get_validator_duties_proposer() {
     ApiTester::new().test_get_validator_duties_proposer().await;
 }
 
+#[tokio::test(core_threads = 2)]
+async fn get_validator_duties_proposer_with_skip_slots() {
+    ApiTester::new()
+        .skip_slots(E::slots_per_epoch() * 2)
+        .test_get_validator_duties_proposer()
+        .await;
+}
+
 #[tokio::test(core_threads = 2)]
 async fn block_production() {
     ApiTester::new().test_block_production().await;