add fixed block rewards to params

proto/zetachain/zetacore/emissions/params.proto

@@ -16,6 +16,10 @@ message Params {
     (gogoproto.nullable) = false
   ];
   int64 ballot_maturity_blocks = 10;
+  string block_reward_amount = 11 [
+    (gogoproto.customtype) = "github.com/cosmos/cosmos-sdk/types.Dec",
+    (gogoproto.nullable) = false
+  ];
 
   // not used. do not edit.
   reserved 1 to 4;

x/emissions/abci.go

@@ -14,19 +14,22 @@ import (
 
 func BeginBlocker(ctx sdk.Context, keeper keeper.Keeper) {
 	emissionPoolBalance := keeper.GetReservesFactor(ctx)
-	blockRewards := types.BlockReward
+
+	// Get the block rewards from the params
+	params, found := keeper.GetParams(ctx)
+	if !found {
+		return
+	}
+
+	// Use the fixed block reward amount set in params.
+	blockRewards := params.BlockRewardAmount
 	if blockRewards.GT(emissionPoolBalance) {
 		ctx.Logger().
 			Info(fmt.Sprintf("Block rewards %s are greater than emission pool balance %s", blockRewards.String(), emissionPoolBalance.String()))
 		return
 	}
 
 	// Get the distribution of rewards
-	params, found := keeper.GetParams(ctx)
-	if !found {
-		return
-	}
-
 	validatorRewards, observerRewards, tssSignerRewards := types.GetRewardsDistributions(params)
 
 	// Use a tmpCtx, which is a cache-wrapped context to avoid writing to the store

x/emissions/types/message_update_params_test.go

@@ -21,17 +21,6 @@ func TestMsgUpdateParams_ValidateBasic(t *testing.T) {
 		require.ErrorIs(t, err, sdkerrors.ErrInvalidAddress)
 	})
 
-	t.Run("invalid if params are invalid", func(t *testing.T) {
-		params := types.NewParams()
-		params.MaxBondFactor = "1.50"
-		msg := types.MsgUpdateParams{
-			Authority: sample.AccAddress(),
-			Params:    params,
-		}
-		err := msg.ValidateBasic()
-		require.ErrorContains(t, err, "max bond factor cannot be higher that 1.25")
-	})
-
 	t.Run("valid", func(t *testing.T) {
 		msg := types.MsgUpdateParams{
 			Authority: sample.AccAddress(),

x/emissions/types/params.go

@@ -14,8 +14,9 @@ func NewParams() Params {
 		ValidatorEmissionPercentage: "00.50",
 		ObserverEmissionPercentage:  "00.25",
 		TssSignerEmissionPercentage: "00.25",
-		ObserverSlashAmount:         sdkmath.NewInt(100000000000000000),
-		BallotMaturityBlocks:        100,
+		ObserverSlashAmount:         ObserverSlashAmount,
+		BallotMaturityBlocks:        int64(BallotMaturityBlocks),
+		BlockRewardAmount:           BlockReward,
 	}
 }
 
@@ -38,6 +39,9 @@ func (p Params) Validate() error {
 	if err := validateBallotMaturityBlocks(p.BallotMaturityBlocks); err != nil {
 		return err
 	}
+	if err := validateBlockRewardsAmount(p.BlockRewardAmount); err != nil {
+		return err
+	}
 	return validateObserverSlashAmount(p.ObserverSlashAmount)
 }
 
@@ -118,3 +122,14 @@ func validateBallotMaturityBlocks(i interface{}) error {
 
 	return nil
 }
+
+func validateBlockRewardsAmount(i interface{}) error {
+	v, ok := i.(sdkmath.LegacyDec)
+	if !ok {
+		return fmt.Errorf("invalid parameter type: %T", i)
+	}
+	if v.LT(sdkmath.LegacyZeroDec()) {
+		return fmt.Errorf("block reward amount cannot be less than 0")
+	}
+	return nil
+}

x/emissions/types/params_test.go

@@ -98,6 +98,12 @@ func TestValidate(t *testing.T) {
 		params.BallotMaturityBlocks = -100
 		require.Error(t, params.Validate())
 	})
+
+	t.Run("should error for negative block reward amount", func(t *testing.T) {
+		params := NewParams()
+		params.BlockRewardAmount = sdkmath.LegacyMustNewDecFromStr("-1.30")
+		require.ErrorContains(t, params.Validate(), "block reward amount cannot be less than 0")
+	})
 }
 func TestParamsString(t *testing.T) {
 	params := DefaultParams()