exclude unscheduled forks from the schedule (#15799)

* exclude unscheduled forks from the schedule

* update tests that relied on fulu being far future

* don't mess with the version->epoch mapping

* LastFork cheats the tests by filtering by far_future_epoch

---------

Co-authored-by: Kasey Kirkham <kasey@users.noreply.github.com>

config/params/config.go

@@ -468,7 +468,7 @@ func (ns *NetworkSchedule) LastEntry() NetworkScheduleEntry {
 // LastFork is the last full fork (this is used by e2e testing)
 func (ns *NetworkSchedule) LastFork() NetworkScheduleEntry {
 	for i := len(ns.entries) - 1; i >= 0; i-- {
-		if ns.entries[i].isFork && ns.entries[i].Epoch != BeaconConfig().FarFutureEpoch {
+		if ns.entries[i].isFork {
 			return ns.entries[i]
 		}
 	}
@@ -527,6 +527,13 @@ func (ns *NetworkSchedule) index(e NetworkScheduleEntry) {
 }
 
 func (ns *NetworkSchedule) prepare(b *BeaconChainConfig) error {
+	// Only keep entries up to FarFutureEpoch.
+	for i := range ns.entries {
+		if ns.entries[i].Epoch == b.FarFutureEpoch {
+			ns.entries = ns.entries[:i]
+			break
+		}
+	}
 	if len(ns.entries) == 0 {
 		return errors.New("cannot compute digests for an empty network schedule")
 	}

config/params/config_test.go

@@ -266,3 +266,24 @@ func testConfigForSchedule(gvr [32]byte) *params.BeaconChainConfig {
 	}
 	return cfg
 }
+
+func TestFilterFarFuture(t *testing.T) {
+	params.SetupTestConfigCleanup(t)
+	params.BeaconConfig().FuluForkEpoch = params.BeaconConfig().FarFutureEpoch
+	params.BeaconConfig().InitializeForkSchedule()
+	last := params.LastNetworkScheduleEntry()
+	require.Equal(t, [4]byte(params.BeaconConfig().ElectraForkVersion), last.ForkVersion)
+}
+
+func TestFarFuturePrepareFilter(t *testing.T) {
+	params.SetupTestConfigCleanup(t)
+	cfg := params.BeaconConfig()
+	oldElectra := cfg.ElectraForkEpoch
+	// This should cause electra to be filtered from the schedule, so looking up the entry for electra's epoch
+	// should return the previous entry (deneb).
+	cfg.ElectraForkEpoch = params.BeaconConfig().FarFutureEpoch
+	cfg.FuluForkEpoch = params.BeaconConfig().FarFutureEpoch
+	params.OverrideBeaconConfig(cfg)
+	entry := params.GetNetworkScheduleEntry(oldElectra)
+	require.Equal(t, [4]byte(params.BeaconConfig().DenebForkVersion), entry.ForkVersion)
+}

config/params/fork.go

@@ -101,6 +101,11 @@ func LastForkEpoch() primitives.Epoch {
 	return BeaconConfig().networkSchedule.LastFork().Epoch
 }
 
+func LastNetworkScheduleEntry() NetworkScheduleEntry {
+	lastIdx := len(BeaconConfig().networkSchedule.entries) - 1
+	return BeaconConfig().networkSchedule.entries[lastIdx]
+}
+
 func GetNetworkScheduleEntry(epoch primitives.Epoch) NetworkScheduleEntry {
 	entry := BeaconConfig().networkSchedule.ForEpoch(epoch)
 	return entry

config/params/fork_test.go

@@ -142,8 +142,8 @@ func TestNextForkData(t *testing.T) {
 		{
 			name:              "after last bpo - should be far future epoch and 0x00000000",
 			currEpoch:         params.LastForkEpoch() + 1,
-			wantedForkVersion: [4]byte(cfg.FuluForkVersion),
-			wantedEpoch:       cfg.FarFutureEpoch,
+			wantedForkVersion: [4]byte(cfg.ElectraForkVersion),
+			wantedEpoch:       cfg.ElectraForkEpoch,
 		},
 	}
 	for _, tt := range tests {