Fix getEpochInfo to use the cluster’s epoch schedule

pkg/rpcserver/get_epoch_info.go

@@ -25,17 +25,15 @@ func (rpcServer *RpcServer) GetEpochInfo(ctx context.Context, p jsonrpc.RawParam
 
 	_ = params
 
-	epoch := global.Epoch()
 	slot := global.Slot()
-	firstSlotInEpoch := rpcServer.epochSchedule.FirstSlotInEpoch(epoch)
-	slotIndex := slot - firstSlotInEpoch
+	epoch, slotIndex := rpcServer.epochSchedule.GetEpochAndSlotIndex(slot)
 
 	resp := GetEpochInfoResp{
-		AbsoluteSlot:     global.Slot(),
+		AbsoluteSlot:     slot,
 		BlockHeight:      global.BlockHeight(),
-		Epoch:            global.Epoch(),
+		Epoch:            epoch,
 		SlotIndex:        slotIndex,
-		SlotsInEpoch:     432000,
+		SlotsInEpoch:     rpcServer.epochSchedule.SlotsInEpoch(epoch),
 		TransactionCount: global.TransactionCount(),
 	}
 

pkg/rpcserver/get_epoch_info_test.go

@@ -0,0 +1,79 @@
+package rpcserver
+
+import (
+	"net/http/httptest"
+	"testing"
+
+	"github.com/Overclock-Validator/mithril/pkg/global"
+	"github.com/Overclock-Validator/mithril/pkg/sealevel"
+	"github.com/gagliardetto/solana-go"
+	solanarpc "github.com/gagliardetto/solana-go/rpc"
+	"github.com/stretchr/testify/require"
+)
+
+func TestGetEpochInfoSchedule(t *testing.T) {
+	savedSlot, savedEpoch := global.Slot(), global.Epoch()
+	t.Cleanup(func() {
+		global.SetSlot(savedSlot)
+		global.SetEpoch(savedEpoch)
+	})
+
+	for _, schedule := range []struct {
+		name  string
+		value sealevel.SysvarEpochSchedule
+		cases []struct{ slot, epoch, index, length uint64 }
+	}{
+		{
+			name:  "short epochs",
+			value: sealevel.SysvarEpochSchedule{SlotsPerEpoch: 32, LeaderScheduleSlotOffset: 32},
+			cases: []struct{ slot, epoch, index, length uint64 }{
+				{0, 0, 0, 32}, {31, 0, 31, 32}, {32, 1, 0, 32}, {79, 2, 15, 32},
+			},
+		},
+		{
+			name:  "normal epochs",
+			value: sealevel.SysvarEpochSchedule{SlotsPerEpoch: 432000, LeaderScheduleSlotOffset: 432000},
+			cases: []struct{ slot, epoch, index, length uint64 }{
+				{431999, 0, 431999, 432000}, {432000, 1, 0, 432000},
+			},
+		},
+		{
+			name: "warmup epochs",
+			value: sealevel.SysvarEpochSchedule{
+				SlotsPerEpoch: 432000, LeaderScheduleSlotOffset: 432000,
+				Warmup: true, FirstNormalEpoch: 14, FirstNormalSlot: 524256,
+			},
+			cases: []struct{ slot, epoch, index, length uint64 }{
+				{0, 0, 0, 32}, {32, 1, 0, 64}, {95, 1, 63, 64},
+				{524255, 13, 262143, 262144}, {524256, 14, 0, 432000},
+			},
+		},
+	} {
+		t.Run(schedule.name, func(t *testing.T) {
+			server := NewRpcServer(nil, 0, &schedule.value, solana.Hash{1})
+			require.NoError(t, server.listener.Close())
+			endpoint := httptest.NewServer(server)
+			t.Cleanup(endpoint.Close)
+			client := solanarpc.New(endpoint.URL)
+			for _, test := range schedule.cases {
+				global.SetSlot(test.slot)
+				global.SetEpoch(test.epoch)
+				got, err := client.GetEpochInfo(t.Context(), solanarpc.CommitmentProcessed)
+				require.NoError(t, err, "slot %d", test.slot)
+				require.Equal(t, test.slot, got.AbsoluteSlot)
+				require.Equal(t, test.epoch, got.Epoch, "slot %d", test.slot)
+				require.Equal(t, test.index, got.SlotIndex, "slot %d", test.slot)
+				require.Equal(t, test.length, got.SlotsInEpoch, "slot %d", test.slot)
+				require.Equal(t, global.BlockHeight(), got.BlockHeight)
+				require.NotNil(t, got.TransactionCount)
+				require.Equal(t, global.TransactionCount(), *got.TransactionCount)
+
+				// Replay publishes slot and epoch separately; keep the response tied to its slot.
+				global.SetEpoch(test.epoch + 1)
+				repeated, err := client.GetEpochInfo(t.Context(), solanarpc.CommitmentProcessed)
+				require.NoError(t, err)
+				require.Equal(t, got, repeated)
+			}
+		})
+	}
+}