chore: Require -gas-fee-margin to be a non-negative integer

Signed-off-by: Jeff Thompson <jeff@thefirst.org>

Author: jefft0

gno.land/pkg/integration/testdata/simulate_gas.txtar

@@ -24,6 +24,14 @@ stdout 'gas fee: 111ugnot'
 gnokey maketx call -pkgpath gno.land/r/simulate -func Hello -gas-fee 1000000ugnot -gas-wanted 2000000 -broadcast -chainid=tendermint_test -simulate only -gas-fee-margin=10 test1
 stdout 'gas fee: 122ugnot'
 
+# -gas-fee-margin should be a number
+! gnokey maketx call -pkgpath gno.land/r/simulate -func Hello -gas-fee 1000000ugnot -gas-wanted 2000000 -broadcast -chainid=tendermint_test -simulate only -gas-fee-margin=zzz test1
+stderr 'invalid value'
+
+# -gas-fee-margin should be non-negative
+! gnokey maketx call -pkgpath gno.land/r/simulate -func Hello -gas-fee 1000000ugnot -gas-wanted 2000000 -broadcast -chainid=tendermint_test -simulate only -gas-fee-margin=-10 test1
+stderr 'invalid value'
+
 -- package/package.gno --
 package call_package
 

tm2/pkg/crypto/keys/client/broadcast.go

@@ -28,7 +28,7 @@ type BroadcastCfg struct {
 	// If true, simulation is attempted but not printed;
 	// the result is only returned in case of an error.
 	testSimulate bool
-	GasFeeMargin int64
+	GasFeeMargin uint64
 }
 
 func NewBroadcastCmd(rootCfg *BaseCfg, io commands.IO) *commands.Command {
@@ -144,7 +144,7 @@ func BroadcastHandler(cfg *BroadcastCfg) (*ctypes.ResultBroadcastTxCommit, error
 	return bres, nil
 }
 
-func estimateGasFee(cli client.ABCIClient, bres *ctypes.ResultBroadcastTxCommit, gasFeeMargin int64) error {
+func estimateGasFee(cli client.ABCIClient, bres *ctypes.ResultBroadcastTxCommit, gasFeeMargin uint64) error {
 	gp := std.GasPrice{}
 	qres, err := cli.ABCIQuery(context.Background(), "auth/gasprice", []byte{})
 	if err != nil {
@@ -162,7 +162,7 @@ func estimateGasFee(cli client.ABCIClient, bres *ctypes.ResultBroadcastTxCommit,
 	fee := bres.DeliverTx.GasUsed/gp.Gas + 1
 	fee = overflow.Mulp(fee, gp.Price.Amount)
 	// gasFeeMargin is a percentage fee buffer to cover the sudden change of gas price
-	feeBuffer := overflow.Mulp(fee, gasFeeMargin) / 100
+	feeBuffer := overflow.Mulp(fee, int64(gasFeeMargin)) / 100
 	fee = overflow.Addp(fee, feeBuffer)
 	s := fmt.Sprintf("estimated gas usage: %d, gas fee: %d%s, current gas price: %s\n", bres.DeliverTx.GasUsed, fee, gp.Price.Denom, gp.String())
 	bres.DeliverTx.Info = s

tm2/pkg/crypto/keys/client/maketx.go

@@ -24,7 +24,7 @@ type MakeTxCfg struct {
 	// Valid options are SimulateTest, SimulateSkip or SimulateOnly.
 	Simulate string
 	// Only used with SimulateOnly
-	GasFeeMargin int64
+	GasFeeMargin uint64
 	ChainID      string
 }
 
@@ -105,7 +105,7 @@ func (c *MakeTxCfg) RegisterFlags(fs *flag.FlagSet) {
 		- only: avoids broadcasting transaction (ie. dry run)`,
 	)
 
-	fs.Int64Var(
+	fs.Uint64Var(
 		&c.GasFeeMargin,
 		"gas-fee-margin",
 		5,