epoching: API for querying the validator set of a given epoch (#236)

proto/babylon/epoching/v1/epoching.proto

@@ -73,3 +73,10 @@ message DelegationLifecycle {
   string del_addr = 1;
   repeated DelegationStateUpdate del_life = 2;
 }
+
+message Validator {
+  // addr is the validator's address (in sdk.ValAddress)
+  bytes addr = 1;
+  // power is the validator's voting power
+  int64 power = 2;
+}

proto/babylon/epoching/v1/query.proto

@@ -45,6 +45,11 @@ service Query {
   rpc DelegationLifecycle(QueryDelegationLifecycleRequest) returns (QueryDelegationLifecycleResponse) {
     option (google.api.http).get = "/babylon/epoching/v1/delegation_lifecycle/{del_addr}";
   }
+
+  // EpochValSet queries the validator set of a given epoch
+  rpc EpochValSet(QueryEpochValSetRequest) returns (QueryEpochValSetResponse) {
+    option (google.api.http).get = "/babylon/epoching/v1/epochs/{epoch_num=*}/validator_set";
+  }
 }
 
 // QueryParamsRequest is the request type for the Query/Params RPC method.
@@ -127,3 +132,14 @@ message QueryDelegationLifecycleRequest {
 message QueryDelegationLifecycleResponse {
   DelegationLifecycle del_life = 1;
 }
+
+message QueryEpochValSetRequest {
+  uint64 epoch_num = 1;
+  cosmos.base.query.v1beta1.PageRequest pagination = 2;
+}
+
+message QueryEpochValSetResponse {
+  repeated babylon.epoching.v1.Validator validators = 1;
+  int64 total_voting_power = 2;
+  cosmos.base.query.v1beta1.PageResponse pagination = 3;
+}

x/checkpointing/keeper/grpc_query_bls_test.go

@@ -1,6 +1,9 @@
 package keeper_test
 
 import (
+	"math/rand"
+	"testing"
+
 	"github.com/babylonchain/babylon/app"
 	"github.com/babylonchain/babylon/crypto/bls12381"
 	"github.com/babylonchain/babylon/testutil/datagen"
@@ -11,8 +14,6 @@ import (
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	"github.com/cosmos/cosmos-sdk/types/query"
 	"github.com/stretchr/testify/require"
-	"math/rand"
-	"testing"
 )
 
 // FuzzQueryBLSKeySet does the following checks
@@ -53,7 +54,7 @@ func FuzzQueryBLSKeySet(f *testing.F) {
 		require.NoError(t, err)
 		require.Len(t, res.ValidatorWithBlsKeys, 1)
 		require.Equal(t, res.ValidatorWithBlsKeys[0].BlsPubKey, genesisBLSPubkey.Bytes())
-		require.Equal(t, res.ValidatorWithBlsKeys[0].ValidatorAddress, genesisVal.Addr.String())
+		require.Equal(t, res.ValidatorWithBlsKeys[0].ValidatorAddress, genesisVal.GetValAddressStr())
 
 		// add n new validators via MsgWrappedCreateValidator
 		n := rand.Intn(3) + 1
@@ -88,7 +89,7 @@ func FuzzQueryBLSKeySet(f *testing.F) {
 		expectedValSet := ek.GetValidatorSet(ctx, 2)
 		require.Len(t, expectedValSet, n+1)
 		for i, expectedVal := range expectedValSet {
-			require.Equal(t, expectedVal.Addr.String(), resp.ValidatorWithBlsKeys[i].ValidatorAddress)
+			require.Equal(t, expectedVal.GetValAddressStr(), resp.ValidatorWithBlsKeys[i].ValidatorAddress)
 		}
 
 		// 3.1 query BLS public keys when there are n+1 validators with limit pagination

x/checkpointing/keeper/keeper.go

@@ -347,7 +347,7 @@ func (k Keeper) GetBLSPubKeySet(ctx sdk.Context, epochNumber uint64) ([]*types.V
 			return nil, err
 		}
 		valWithblsKeys[i] = &types.ValidatorWithBlsKey{
-			ValidatorAddress: val.Addr.String(),
+			ValidatorAddress: val.GetValAddressStr(),
 			BlsPubKey:        pubkey,
 		}
 	}

x/checkpointing/keeper/msg_server_test.go

@@ -1,6 +1,9 @@
 package keeper_test
 
 import (
+	"math/rand"
+	"testing"
+
 	"github.com/babylonchain/babylon/app"
 	appparams "github.com/babylonchain/babylon/app/params"
 	"github.com/babylonchain/babylon/crypto/bls12381"
@@ -14,8 +17,6 @@ import (
 	stakingtypes "github.com/cosmos/cosmos-sdk/x/staking/types"
 	"github.com/stretchr/testify/require"
 	"github.com/tendermint/tendermint/crypto/ed25519"
-	"math/rand"
-	"testing"
 )
 
 // FuzzWrappedCreateValidator tests adding new validators via
@@ -76,7 +77,7 @@ func FuzzWrappedCreateValidator(f *testing.F) {
 		for _, msg := range wcvMsgs {
 			found := false
 			for _, val := range valSet {
-				if msg.MsgCreateValidator.ValidatorAddress == val.Addr.String() {
+				if msg.MsgCreateValidator.ValidatorAddress == val.GetValAddressStr() {
 					found = true
 				}
 			}

x/epoching/keeper/epoch_slashed_val_set_test.go

@@ -43,7 +43,7 @@ func FuzzSlashedValSet(f *testing.F) {
 		sortVals(excpectedSlashedVals)
 		actualSlashedVals = types.NewSortedValidatorSet(actualSlashedVals)
 		for i := range actualSlashedVals {
-			require.Equal(t, excpectedSlashedVals[i], actualSlashedVals[i].Addr)
+			require.Equal(t, excpectedSlashedVals[i], actualSlashedVals[i].GetValAddress())
 		}
 
 		// go to the 1st block and thus epoch 1

x/epoching/keeper/epoch_val_set_test.go

@@ -26,7 +26,7 @@ func FuzzEpochValSet(f *testing.F) {
 		for i := range getValSet {
 			consAddr, err := valSet[i].GetConsAddr()
 			require.NoError(t, err)
-			require.Equal(t, sdk.ValAddress(consAddr), getValSet[i].Addr)
+			require.Equal(t, sdk.ValAddress(consAddr), getValSet[i].GetValAddress())
 		}
 
 		// generate a random number of new blocks
@@ -41,7 +41,7 @@ func FuzzEpochValSet(f *testing.F) {
 		for i := range getValSet2 {
 			consAddr, err := valSet[i].GetConsAddr()
 			require.NoError(t, err)
-			require.Equal(t, sdk.ValAddress(consAddr), getValSet[i].Addr)
+			require.Equal(t, sdk.ValAddress(consAddr), getValSet[i].GetValAddress())
 		}
 	})
 }

x/epoching/keeper/grpc_query.go

@@ -175,3 +175,41 @@ func (k Keeper) DelegationLifecycle(c context.Context, req *types.QueryDelegatio
 		DelLife: lc,
 	}, nil
 }
+
+func (k Keeper) EpochValSet(c context.Context, req *types.QueryEpochValSetRequest) (*types.QueryEpochValSetResponse, error) {
+	ctx := sdk.UnwrapSDKContext(c)
+
+	epoch := k.GetEpoch(ctx)
+	if epoch.EpochNumber < req.EpochNum {
+		return nil, types.ErrUnknownEpochNumber
+	}
+
+	totalVotingPower := k.GetTotalVotingPower(ctx, epoch.EpochNumber)
+
+	vals := []*types.Validator{}
+	epochValSetStore := k.valSetStore(ctx, epoch.EpochNumber)
+	pageRes, err := query.Paginate(epochValSetStore, req.Pagination, func(key, value []byte) error {
+		// Here key is the validator's ValAddress, and value is the voting power
+		var power sdk.Int
+		if err := power.Unmarshal(value); err != nil {
+			panic(sdkerrors.Wrap(types.ErrUnmarshal, err.Error())) // this only happens upon a programming error
+		}
+		val := types.Validator{
+			Addr:  key,
+			Power: power.Int64(),
+		}
+		// append to msgs
+		vals = append(vals, &val)
+		return nil
+	})
+	if err != nil {
+		return nil, status.Error(codes.Internal, err.Error())
+	}
+
+	resp := &types.QueryEpochValSetResponse{
+		Validators:       vals,
+		TotalVotingPower: totalVotingPower,
+		Pagination:       pageRes,
+	}
+	return resp, nil
+}

x/epoching/keeper/grpc_query_test.go

@@ -1,10 +1,11 @@
 package keeper_test
 
 import (
-	stakingtypes "github.com/cosmos/cosmos-sdk/x/staking/types"
 	"math/rand"
 	"testing"
 
+	stakingtypes "github.com/cosmos/cosmos-sdk/x/staking/types"
+
 	"github.com/babylonchain/babylon/testutil/datagen"
 	"github.com/babylonchain/babylon/x/epoching/testepoching"
 	"github.com/babylonchain/babylon/x/epoching/types"
@@ -18,15 +19,14 @@ import (
 // 2. When EpochInterval is 0, ensure `Validate` returns an error
 // 3. Randomly set the param via query and check if the param has been updated
 func FuzzParamsQuery(f *testing.F) {
-	f.Add(uint64(11111), int64(23))
-	f.Add(uint64(22222), int64(330))
-	f.Add(uint64(22222), int64(101))
+	datagen.AddRandomSeedsToFuzzer(f, 10)
 
-	f.Fuzz(func(t *testing.T, epochInterval uint64, seed int64) {
+	f.Fuzz(func(t *testing.T, seed int64) {
 		rand.Seed(seed)
 
 		// params generated by fuzzer
 		params := types.DefaultParams()
+		epochInterval := datagen.RandomInt(20)
 		params.EpochInterval = epochInterval
 
 		// test the case of EpochInterval == 0
@@ -62,11 +62,13 @@ func FuzzParamsQuery(f *testing.F) {
 // 2. query the current epoch and boundary
 // 3. compare them with the correctly calculated ones
 func FuzzCurrentEpoch(f *testing.F) {
-	f.Add(uint64(1111))
-	f.Add(uint64(2222))
-	f.Add(uint64(3333))
+	datagen.AddRandomSeedsToFuzzer(f, 10)
+
+	f.Fuzz(func(t *testing.T, seed int64) {
+		rand.Seed(seed)
+
+		increment := datagen.RandomInt(100)
 
-	f.Fuzz(func(t *testing.T, increment uint64) {
 		helper := testepoching.NewHelper(t)
 		ctx, keeper, queryClient := helper.Ctx, helper.EpochingKeeper, helper.QueryClient
 		wctx := sdk.WrapSDKContext(ctx)
@@ -81,15 +83,12 @@ func FuzzCurrentEpoch(f *testing.F) {
 	})
 }
 
-// FuzzEpochMsgs fuzzes queryClient.EpochMsgs
+// FuzzEpochMsgsQuery fuzzes queryClient.EpochMsgs
 // 1. randomly generate msgs and limit in pagination
 // 2. check the returned msg was previously enqueued
 // NOTE: Msgs in QueryEpochMsgsResponse are out-of-roder
-func FuzzEpochMsgs(f *testing.F) {
-	f.Add(int64(12))
-	f.Add(int64(44))
-	f.Add(int64(422))
-	f.Add(int64(4222))
+func FuzzEpochMsgsQuery(f *testing.F) {
+	datagen.AddRandomSeedsToFuzzer(f, 10)
 
 	f.Fuzz(func(t *testing.T, seed int64) {
 		rand.Seed(seed)
@@ -137,3 +136,41 @@ func FuzzEpochMsgs(f *testing.F) {
 		require.Error(t, err)
 	})
 }
+
+// FuzzEpochMsgs fuzzes queryClient.EpochValSet
+// TODO (stateful tests): create some random validators and check if the resulting validator set is consistent or not (require mocking MsgWrappedCreateValidator)
+func FuzzEpochValSetQuery(f *testing.F) {
+	datagen.AddRandomSeedsToFuzzer(f, 10)
+
+	f.Fuzz(func(t *testing.T, seed int64) {
+		rand.Seed(seed)
+
+		helper := testepoching.NewHelperWithValSet(t)
+		ctx, queryClient := helper.Ctx, helper.QueryClient
+
+		limit := uint64(rand.Int() % 100)
+		req := &types.QueryEpochValSetRequest{
+			EpochNum: 0,
+			Pagination: &query.PageRequest{
+				Limit: limit,
+			},
+		}
+
+		resp, err := queryClient.EpochValSet(ctx, req)
+		require.NoError(t, err)
+
+		// generate a random number of new blocks
+		numIncBlocks := rand.Uint64()%1000 + 1
+		for i := uint64(0); i < numIncBlocks; i++ {
+			ctx = helper.GenAndApplyEmptyBlock()
+		}
+
+		// check whether the validator set remains the same or not
+		resp2, err := queryClient.EpochValSet(ctx, req)
+		require.NoError(t, err)
+		require.Equal(t, len(resp.Validators), len(resp2.Validators))
+		for i := range resp2.Validators {
+			require.Equal(t, resp.Validators[i].Addr, resp2.Validators[i].Addr)
+		}
+	})
+}