feat(x/gov): add min_stake_to_vote parameter

CHANGELOG.md

@@ -40,6 +40,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ### Features
 
+* (x/gov) []() Add `min_stake_to_vote` gov parameter. If specified, it allows chains to set a minimum amount of stake required to vote on proposals.
 * (x/staking) [#18142](https://github.com/cosmos/cosmos-sdk/pull/18142) introduce `key_rotation_fee` param to calculate fees while rotating the keys
 * (server) [#18110](https://github.com/cosmos/cosmos-sdk/pull/18110) Start gRPC & API server in standalone mode
 * (client) [#18101](https://github.com/cosmos/cosmos-sdk/pull/18101) Add a `keyring-default-keyname` in `client.toml` for specifying a default key name, and skip the need to use the `--from` flag when signing transactions.

proto/cosmos/gov/v1/gov.proto

@@ -214,18 +214,18 @@ message Params {
   // Duration of the voting period.
   google.protobuf.Duration voting_period = 3 [(gogoproto.stdduration) = true];
 
-  //  Minimum percentage of total stake needed to vote for a result to be
-  //  considered valid.
+  // Minimum percentage of total stake needed to vote for a result to be
+  // considered valid.
   string quorum = 4 [(cosmos_proto.scalar) = "cosmos.Dec"];
 
-  //  Minimum proportion of Yes votes for proposal to pass. Default value: 0.5.
+  // Minimum proportion of Yes votes for proposal to pass. Default value: 0.5.
   string threshold = 5 [(cosmos_proto.scalar) = "cosmos.Dec"];
 
-  //  Minimum value of Veto votes to Total votes ratio for proposal to be
-  //  vetoed. Default value: 1/3.
+  // Minimum value of Veto votes to Total votes ratio for proposal to be
+  // vetoed. Default value: 1/3.
   string veto_threshold = 6 [(cosmos_proto.scalar) = "cosmos.Dec"];
 
-  //  The ratio representing the proportion of the deposit value that must be paid at proposal submission.
+  // The ratio representing the proportion of the deposit value that must be paid at proposal submission.
   string min_initial_deposit_ratio = 7 [(cosmos_proto.scalar) = "cosmos.Dec"];
 
   // The cancel ratio which will not be returned back to the depositors when a proposal is cancelled.
@@ -249,16 +249,29 @@ message Params {
   // Since: cosmos-sdk 0.50
   string expedited_threshold = 11 [(cosmos_proto.scalar) = "cosmos.Dec"];
 
-  //  Minimum expedited deposit for a proposal to enter voting period.
+  // Minimum expedited deposit for a proposal to enter voting period.
   repeated cosmos.base.v1beta1.Coin expedited_min_deposit = 12
       [(gogoproto.nullable) = false, (amino.dont_omitempty) = true];
 
-  // burn deposits if a proposal does not meet quorum
+  // Burn deposits if a proposal does not meet quorum
+  //
+  // Since: cosmos-sdk v0.47
   bool burn_vote_quorum = 13;
 
-  // burn deposits if the proposal does not enter voting period
+  // Burn deposits if the proposal does not enter voting period
+  //
+  // Since: cosmos-sdk v0.47
   bool burn_proposal_deposit_prevote = 14;
 
-  // burn deposits if quorum with vote type no_veto is met
+  // Burn deposits if quorum with vote type no_veto is met
+  //
+  // Since: cosmos-sdk v0.47
   bool burn_vote_veto = 15;
+
+  // min_stake_to_vote defines the minimum stake to vote on a proposal
+  // If the voter has less than min_stake_to_vote, the vote cannot vote.
+  // If min_stake_to_vote is not set, the vote will be counted regardless of the voter's stake
+  //
+  // Since: cosmos-sdk 0.50
+  cosmos.base.v1beta1.Coin min_stake_to_vote = 16;
 }

x/gov/README.md

@@ -645,9 +645,10 @@ upon receiving txGovDeposit from sender do
 
 ### Vote
 
-Once `ActiveParam.MinDeposit` is reached, voting period starts. From there,
-bonded Atom holders are able to send `MsgVote` transactions to cast their
-vote on the proposal.
+Once `ActiveParam.MinDeposit` is reached, voting period starts.
+From there, bonded Atom holders are able to send `MsgVote` transactions to cast their vote on the proposal.
+Chains have the ability to limit voting to certain account having a minimum stake.
+This parameter is called `MinStakeToVote` and is set to 0 by default.
 
 ```protobuf reference
 https://github.com/cosmos/cosmos-sdk/blob/v0.47.0-rc1/proto/cosmos/gov/v1/tx.proto#L92-L108
@@ -661,35 +662,6 @@ https://github.com/cosmos/cosmos-sdk/blob/v0.47.0-rc1/proto/cosmos/gov/v1/tx.pro
 Gas cost for this message has to take into account the future tallying of the vote in EndBlocker.
 :::
 
-Next is a pseudocode outline of the way `MsgVote` transactions are handled:
-
-```go
-  // PSEUDOCODE //
-  // Check if MsgVote is valid. If it is, count vote//
-
-  upon receiving txGovVote from sender do
-    // check if proposal is correctly formatted. Includes fee payment.
-
-    if !correctlyFormatted(txGovDeposit)
-      throw
-
-    proposal = load(Proposals, <txGovDeposit.ProposalID|'proposal'>)
-
-    if (proposal == nil)
-      // There is no proposal for this proposalID
-      throw
-
-
-    if  (proposal.CurrentStatus == ProposalStatusActive)
-
-
-        // Sender can vote if
-        // Proposal is active
-        // Sender has some bonds
-
-        store(Governance, <txGovVote.ProposalID|'addresses'|sender>, txGovVote.Vote)   // Voters can vote multiple times. Re-voting overrides previous vote. This is ok because tallying is done once at the end.
-```
-
 ## Events
 
 The governance module emits the following events:
@@ -767,11 +739,11 @@ The governance module contains the following parameters:
 | expedited_threshold           | string (time ns) | "0.667000000000000000"                  |
 | expedited_voting_period       | string (time ns) | "86400000000000" (8600s)                |
 | expedited_min_deposit         | array (coins)    | [{"denom":"uatom","amount":"50000000"}] |
-| burn_proposal_deposit_prevote | bool             | false                                    |
+| burn_proposal_deposit_prevote | bool             | false                                   |
 | burn_vote_quorum              | bool             | false                                   |
 | burn_vote_veto                | bool             | true                                    |
-| min_initial_deposit_ratio                | string             | "0.1"                                    |
-
+| min_initial_deposit_ratio      | string          | "0.1"                                   |
+| min_stake_to_vote             | string (coin)    | {"denom":"uatom","amount":"10000000"}   |
 
 **NOTE**: The governance module contains parameters that are objects unlike other
 modules. If only a subset of parameters are desired to be changed, only they need

x/gov/keeper/msg_server_test.go

@@ -451,6 +451,34 @@ func (suite *KeeperTestSuite) TestMsgVote() {
 			expErr:    true,
 			expErrMsg: longAddressError,
 		},
+		"minimum stake not met": {
+			preRun: func() uint64 {
+				minStake := sdk.NewCoin(sdk.DefaultBondDenom, sdkmath.NewInt(1))
+				params.MinStakeToVote = &minStake
+				_ = suite.govKeeper.Params.Set(suite.ctx, params)
+
+				msg, err := v1.NewMsgSubmitProposal(
+					[]sdk.Msg{bankMsg},
+					minDeposit,
+					proposer.String(),
+					"",
+					"Proposal",
+					"description of proposal",
+					false,
+				)
+				suite.Require().NoError(err)
+
+				res, err := suite.msgSrvr.SubmitProposal(suite.ctx, msg)
+				suite.Require().NoError(err)
+				suite.Require().NotNil(res.ProposalId)
+				return res.ProposalId
+			},
+			option:    v1.VoteOption_VOTE_OPTION_YES,
+			voter:     proposer,
+			metadata:  "",
+			expErr:    false,
+			expErrMsg: "voter has too not enough staked token to vote",
+		},
 		"all good": {
 			preRun: func() uint64 {
 				msg, err := v1.NewMsgSubmitProposal(

x/gov/keeper/vote.go

@@ -6,6 +6,7 @@ import (
 
 	"cosmossdk.io/collections"
 	"cosmossdk.io/errors"
+	"cosmossdk.io/math"
 
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	"github.com/cosmos/cosmos-sdk/x/gov/types"
@@ -14,6 +15,17 @@ import (
 
 // AddVote adds a vote on a specific proposal
 func (keeper Keeper) AddVote(ctx context.Context, proposalID uint64, voterAddr sdk.AccAddress, options v1.WeightedVoteOptions, metadata string) error {
+	// Check if voter has enough staked token to vote.
+	params, err := keeper.Params.Get(ctx)
+	if err != nil {
+		return fmt.Errorf("failed to get gov params: %w", err)
+	}
+
+	stakedCoins := sdk.NewCoin(sdk.DefaultBondDenom, math.ZeroInt()) // todo
+	if stakedCoins.IsLT(*params.MinStakeToVote) {
+		return fmt.Errorf("voter has too not enough staked token to vote: minimum %s, got %s", params.MinStakeToVote, stakedCoins)
+	}
+
 	// Check if proposal is in voting period.
 	inVotingPeriod, err := keeper.VotingPeriodProposals.Has(ctx, proposalID)
 	if err != nil {

x/gov/migrations/v5/store.go

@@ -21,6 +21,7 @@ var (
 //
 // Addition of the new proposal expedited parameters that are set to 0 by default.
 // Set of default chain constitution.
+// Set of default minimum stake to vote.
 func MigrateStore(ctx sdk.Context, storeService corestoretypes.KVStoreService, cdc codec.BinaryCodec, constitutionCollection collections.Item[string]) error {
 	store := storeService.OpenKVStore(ctx)
 	paramsBz, err := store.Get(ParamsKey)
@@ -40,6 +41,7 @@ func MigrateStore(ctx sdk.Context, storeService corestoretypes.KVStoreService, c
 	params.ExpeditedThreshold = defaultParams.ExpeditedThreshold
 	params.ProposalCancelRatio = defaultParams.ProposalCancelRatio
 	params.ProposalCancelDest = defaultParams.ProposalCancelDest
+	params.MinStakeToVote = defaultParams.MinStakeToVote
 
 	bz, err := cdc.Marshal(&params)
 	if err != nil {

x/gov/migrations/v5/store_test.go

@@ -45,6 +45,7 @@ func TestMigrateStore(t *testing.T) {
 	require.Equal(t, v1.DefaultParams().ExpeditedMinDeposit, params.ExpeditedMinDeposit)
 	require.Equal(t, v1.DefaultParams().ExpeditedThreshold, params.ExpeditedThreshold)
 	require.Equal(t, v1.DefaultParams().ExpeditedVotingPeriod, params.ExpeditedVotingPeriod)
+	require.Equal(t, v1.DefaultParams().MinStakeToVote, params.MinStakeToVote)
 
 	// Check constitution
 	result, err := constitutionCollection.Get(ctx)

x/gov/simulation/genesis.go

@@ -28,6 +28,7 @@ const (
 	ExpeditedThreshold    = "expedited_threshold"
 	Veto                  = "veto"
 	ProposalCancelRate    = "proposal_cancel_rate"
+	MinStakeToVote        = "min_stake_to_vote"
 
 	// ExpeditedThreshold must be at least as large as the regular Threshold
 	// Therefore, we use this break out point in randomization.
@@ -94,6 +95,11 @@ func GenVeto(r *rand.Rand) sdkmath.LegacyDec {
 	return sdkmath.LegacyNewDecWithPrec(int64(simulation.RandIntBetween(r, 250, 334)), 3)
 }
 
+// GenMinStakeToVote returns randomized MinStakeToVote
+func GenMinStakeToVote(r *rand.Rand, bondDenom string) sdk.Coin {
+	return sdk.NewInt64Coin(bondDenom, int64(simulation.RandIntBetween(r, 0, 1)))
+}
+
 // RandomizedGenState generates a random GenesisState for gov
 func RandomizedGenState(simState *module.SimulationState) {
 	startingProposalID := uint64(simState.Rand.Intn(100))
@@ -131,9 +137,12 @@ func RandomizedGenState(simState *module.SimulationState) {
 	var veto sdkmath.LegacyDec
 	simState.AppParams.GetOrGenerate(Veto, &veto, simState.Rand, func(r *rand.Rand) { veto = GenVeto(r) })
 
+	var minStakeToVote sdk.Coin
+	simState.AppParams.GetOrGenerate(MinStakeToVote, &minStakeToVote, simState.Rand, func(r *rand.Rand) { minStakeToVote = GenMinStakeToVote(r, simState.BondDenom) })
+
 	govGenesis := v1.NewGenesisState(
 		startingProposalID,
-		v1.NewParams(minDeposit, expeditedMinDeposit, depositPeriod, votingPeriod, expeditedVotingPeriod, quorum.String(), threshold.String(), expitedVotingThreshold.String(), veto.String(), minInitialDepositRatio.String(), proposalCancelRate.String(), "", simState.Rand.Intn(2) == 0, simState.Rand.Intn(2) == 0, simState.Rand.Intn(2) == 0),
+		v1.NewParams(minDeposit, expeditedMinDeposit, depositPeriod, votingPeriod, expeditedVotingPeriod, quorum.String(), threshold.String(), expitedVotingThreshold.String(), veto.String(), minInitialDepositRatio.String(), proposalCancelRate.String(), "", simState.Rand.Intn(2) == 0, simState.Rand.Intn(2) == 0, simState.Rand.Intn(2) == 0, minStakeToVote),
 	)
 
 	bz, err := json.MarshalIndent(&govGenesis, "", " ")

x/gov/simulation/genesis_test.go

@@ -51,6 +51,7 @@ func TestRandomizedGenState(t *testing.T) {
 		tallyExpeditedThreshold = "0.545000000000000000"
 		tallyVetoThreshold      = "0.327000000000000000"
 		minInitialDepositDec    = "0.880000000000000000"
+		minStakeToVote          = "0stake"
 	)
 
 	assert.Equal(t, "272stake", govGenesis.Params.MinDeposit[0].String())
@@ -62,6 +63,8 @@ func TestRandomizedGenState(t *testing.T) {
 	assert.Equal(t, tallyThreshold, govGenesis.Params.Threshold)
 	assert.Equal(t, tallyExpeditedThreshold, govGenesis.Params.ExpeditedThreshold)
 	assert.Equal(t, tallyVetoThreshold, govGenesis.Params.VetoThreshold)
+	assert.Equal(t, minInitialDepositDec, govGenesis.Params.MinInitialDepositRatio)
+	assert.Equal(t, minStakeToVote, govGenesis.Params.MinStakeToVote.String())
 	assert.Equal(t, uint64(0x28), govGenesis.StartingProposalId)
 	assert.DeepEqual(t, []*v1.Deposit{}, govGenesis.Deposits)
 	assert.DeepEqual(t, []*v1.Vote{}, govGenesis.Votes)