[Gateway] Enforce minimum stake when staking

x/gateway/keeper/msg_server_stake_gateway.go

@@ -5,6 +5,8 @@ import (
 	"fmt"
 
 	sdk "github.com/cosmos/cosmos-sdk/types"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
 
 	"github.com/pokt-network/poktroll/telemetry"
 	"github.com/pokt-network/poktroll/x/gateway/types"
@@ -24,46 +26,67 @@ func (k msgServer) StakeGateway(
 	ctx := sdk.UnwrapSDKContext(goCtx)
 
 	logger := k.Logger().With("method", "StakeGateway")
-	logger.Info(fmt.Sprintf("About to stake gateway with msg: %v", msg))
+	logger.Info(fmt.Sprintf("about to stake gateway with msg: %v", msg))
 
 	if err := msg.ValidateBasic(); err != nil {
-		return nil, err
+		return nil, status.Error(codes.InvalidArgument, err.Error())
+	}
+
+	// Retrieve the address of the gateway
+	gatewayAddress, err := sdk.AccAddressFromBech32(msg.Address)
+	// NB: This SHOULD NEVER happen because msg.ValidateBasic() validates the address as bech32.
+	if err != nil {
+		// TODO_TECHDEBT(#384): determine whether to continue using cosmos logger for debug level.
+		logger.Info(fmt.Sprintf("could not parse address %q", msg.Address))
+		return nil, status.Error(codes.InvalidArgument, err.Error())
 	}
 
 	// Check if the gateway already exists or not
-	var err error
 	var coinsToEscrow sdk.Coin
 	gateway, isGatewayFound := k.GetGateway(ctx, msg.Address)
 	if !isGatewayFound {
-		logger.Info(fmt.Sprintf("Gateway not found. Creating new gateway for address %q", msg.Address))
+		logger.Info(fmt.Sprintf("gateway not found. Creating new gateway for address %q", msg.Address))
 		gateway = k.createGateway(ctx, msg)
 		coinsToEscrow = *msg.Stake
 	} else {
-		logger.Info(fmt.Sprintf("Gateway found. About to try and update gateway for address %q", msg.Address))
+		logger.Info(fmt.Sprintf("gateway found. About to try and update gateway for address %q", msg.Address))
 		currGatewayStake := *gateway.Stake
 		if err = k.updateGateway(ctx, &gateway, msg); err != nil {
 			logger.Error(fmt.Sprintf("could not update gateway for address %q due to error %v", msg.Address, err))
-			return nil, err
+			return nil, status.Error(codes.InvalidArgument, err.Error())
 		}
 		coinsToEscrow, err = (*msg.Stake).SafeSub(currGatewayStake)
 		if err != nil {
-			return nil, err
+			return nil, status.Error(
+				codes.InvalidArgument,
+				types.ErrGatewayInvalidStake.Wrapf(
+					"stake (%s) must be higher than previous stake (%s)",
+					msg.Stake, currGatewayStake,
+				).Error(),
+			)
 		}
-		logger.Info(fmt.Sprintf("Gateway is going to escrow an additional %+v coins", coinsToEscrow))
+		logger.Info(fmt.Sprintf("gateway is going to escrow an additional %+v coins", coinsToEscrow))
 	}
 
-	// Must always stake or upstake (> 0 delta)
+	// MUST ALWAYS stake or upstake (> 0 delta).
 	if coinsToEscrow.IsZero() {
-		logger.Warn(fmt.Sprintf("Gateway %q must escrow more than 0 additional coins", msg.Address))
-		return nil, types.ErrGatewayInvalidStake.Wrapf("gateway %q must escrow more than 0 additional coins", msg.Address)
+		errMsg := fmt.Sprintf("gateway %q must escrow more than 0 additional coins", msg.GetAddress())
+		logger.Info(errMsg)
+		return nil, status.Error(
+			codes.InvalidArgument,
+			types.ErrGatewayInvalidStake.Wrap(errMsg).Error(),
+		)
 	}
 
-	// Retrieve the address of the gateway
-	gatewayAddress, err := sdk.AccAddressFromBech32(msg.Address)
-	if err != nil {
-		// TODO_TECHDEBT(#384): determine whether to continue using cosmos logger for debug level.
-		logger.Error(fmt.Sprintf("could not parse address %q", msg.Address))
-		return nil, err
+	// MUST ALWAYS have at least minimum stake.
+	minStake := k.GetParams(ctx).MinStake
+	if msg.Stake.Amount.LT(minStake.Amount) {
+		errFmt := "gateway %q must stake at least %s"
+		logger.Info(fmt.Sprintf(errFmt, msg.Address, minStake))
+		return nil, status.Error(
+			codes.InvalidArgument,
+			types.ErrGatewayInvalidStake.Wrapf(errFmt, msg.Address, minStake).Error(),
+		)
 	}
 
 	// Send the coins from the gateway to the staked gateway pool

x/gateway/keeper/msg_server_stake_gateway_test.go

@@ -4,51 +4,52 @@ import (
 	"testing"
 
 	"cosmossdk.io/math"
-	sdk "github.com/cosmos/cosmos-sdk/types"
+	cosmostypes "github.com/cosmos/cosmos-sdk/types"
 	"github.com/stretchr/testify/require"
 
+	"github.com/pokt-network/poktroll/app/volatile"
 	keepertest "github.com/pokt-network/poktroll/testutil/keeper"
 	"github.com/pokt-network/poktroll/testutil/sample"
 	"github.com/pokt-network/poktroll/x/gateway/keeper"
-	"github.com/pokt-network/poktroll/x/gateway/types"
+	gatewaytypes "github.com/pokt-network/poktroll/x/gateway/types"
 )
 
 func TestMsgServer_StakeGateway_SuccessfulCreateAndUpdate(t *testing.T) {
 	k, ctx := keepertest.GatewayKeeper(t)
 	srv := keeper.NewMsgServerImpl(k)
 
-	// Generate an address for the gateway
+	// Generate an address for the gateway.
 	addr := sample.AccAddress()
 
-	// Verify that the gateway does not exist yet
+	// Verify that the gateway does not exist yet.
 	_, isGatewayFound := k.GetGateway(ctx, addr)
 	require.False(t, isGatewayFound)
 
-	// Prepare the gateway
-	initialStake := sdk.NewCoin("upokt", math.NewInt(100))
-	stakeMsg := &types.MsgStakeGateway{
+	// Prepare the gateway.
+	initialStake := cosmostypes.NewCoin("upokt", math.NewInt(100))
+	stakeMsg := &gatewaytypes.MsgStakeGateway{
 		Address: addr,
 		Stake:   &initialStake,
 	}
 
-	// Stake the gateway
+	// Stake the gateway.
 	_, err := srv.StakeGateway(ctx, stakeMsg)
 	require.NoError(t, err)
 
-	// Verify that the gateway exists
+	// Verify that the gateway exists.
 	foundGateway, isGatewayFound := k.GetGateway(ctx, addr)
 	require.True(t, isGatewayFound)
 	require.Equal(t, addr, foundGateway.Address)
 	require.Equal(t, initialStake.Amount, foundGateway.Stake.Amount)
 
-	// Prepare an updated gateway with a higher stake
-	updatedStake := sdk.NewCoin("upokt", math.NewInt(200))
-	updateMsg := &types.MsgStakeGateway{
+	// Prepare an updated gateway with a higher stake.
+	updatedStake := cosmostypes.NewCoin("upokt", math.NewInt(200))
+	updateMsg := &gatewaytypes.MsgStakeGateway{
 		Address: addr,
 		Stake:   &updatedStake,
 	}
 
-	// Update the staked gateway
+	// Update the staked gateway.
 	_, err = srv.StakeGateway(ctx, updateMsg)
 	require.NoError(t, err)
 	foundGateway, isGatewayFound = k.GetGateway(ctx, addr)
@@ -60,33 +61,61 @@ func TestMsgServer_StakeGateway_FailLoweringStake(t *testing.T) {
 	k, ctx := keepertest.GatewayKeeper(t)
 	srv := keeper.NewMsgServerImpl(k)
 
-	// Prepare the gateway
+	// Prepare the gateway.
 	addr := sample.AccAddress()
-	initialStake := sdk.NewCoin("upokt", math.NewInt(100))
-	stakeMsg := &types.MsgStakeGateway{
+	initialStake := cosmostypes.NewCoin("upokt", math.NewInt(100))
+	stakeMsg := &gatewaytypes.MsgStakeGateway{
 		Address: addr,
 		Stake:   &initialStake,
 	}
 
-	// Stake the gateway & verify that the gateway exists
+	// Stake the gateway & verify that the gateway exists.
 	_, err := srv.StakeGateway(ctx, stakeMsg)
 	require.NoError(t, err)
 	_, isGatewayFound := k.GetGateway(ctx, addr)
 	require.True(t, isGatewayFound)
 
-	// Prepare an updated gateway with a lower stake
-	updatedStake := sdk.NewCoin("upokt", math.NewInt(50))
-	updateMsg := &types.MsgStakeGateway{
+	// Prepare an updated gateway with a lower stake.
+	updatedStake := cosmostypes.NewCoin("upokt", math.NewInt(50))
+	updateMsg := &gatewaytypes.MsgStakeGateway{
 		Address: addr,
 		Stake:   &updatedStake,
 	}
 
-	// Verify that it fails
+	// Verify that it fails.
 	_, err = srv.StakeGateway(ctx, updateMsg)
 	require.Error(t, err)
 
-	// Verify that the gateway stake is unchanged
+	// Verify that the gateway stake is unchanged.
 	gatewayFound, isGatewayFound := k.GetGateway(ctx, addr)
 	require.True(t, isGatewayFound)
 	require.Equal(t, initialStake.Amount, gatewayFound.Stake.Amount)
 }
+
+func TestMsgServer_StakeGateway_FailBelowMinStake(t *testing.T) {
+	k, ctx := keepertest.GatewayKeeper(t)
+	srv := keeper.NewMsgServerImpl(k)
+
+	addr := sample.AccAddress()
+	gatewayStake := cosmostypes.NewInt64Coin(volatile.DenomuPOKT, 100)
+	minStake := gatewayStake.AddAmount(math.NewInt(1))
+	expectedErr := gatewaytypes.ErrGatewayInvalidStake.Wrapf("gateway %q must stake at least %s", addr, minStake)
+
+	// Set the minimum stake to be greater than the gateway stake.
+	params := k.GetParams(ctx)
+	params.MinStake = &minStake
+	err := k.SetParams(ctx, params)
+	require.NoError(t, err)
+
+	// Prepare the gateway.
+	stakeMsg := &gatewaytypes.MsgStakeGateway{
+		Address: addr,
+		Stake:   &gatewayStake,
+	}
+
+	// Attempt to stake the gateway & verify that the gateway does NOT exist.
+	_, err = srv.StakeGateway(ctx, stakeMsg)
+	require.ErrorContains(t, err, expectedErr.Error())
+	_, isGatewayFound := k.GetGateway(ctx, addr)
+	require.False(t, isGatewayFound)
+}