bind: fix dynamic-fee tx selection and DeployContract construction

thorclient/bind/contract.go

@@ -17,6 +17,7 @@ import (
 	"github.com/ethereum/go-ethereum/common/hexutil"
 
 	"github.com/vechain/thor/v2/test"
+	"github.com/vechain/thor/v2/test/datagen"
 	"github.com/vechain/thor/v2/thor"
 	"github.com/vechain/thor/v2/thorclient"
 	"github.com/vechain/thor/v2/tx"
@@ -50,32 +51,49 @@ func DeployContract(client *thorclient.Client, signer Signer, abiData []byte, by
 	if err != nil {
 		return nil, err
 	}
+	clause := tx.NewClause(nil).WithData(bc)
 
 	tag, err := client.ChainTag()
 	if err != nil {
 		return nil, err
 	}
+	best, err := client.Block("best")
+	if err != nil {
+		return nil, fmt.Errorf("failed to get best block: %w", err)
+	}
+
+	// Estimate gas from intrinsic gas plus simulated execution gas.
+	gas, err := tx.IntrinsicGas(clause)
+	if err != nil {
+		return nil, fmt.Errorf("failed to calculate intrinsic gas: %w", err)
+	}
+	caller := signer.Address()
+	simulation, err := simulateClause(client, caller, clause)
+	if err != nil {
+		return nil, fmt.Errorf("failed to simulate deployment clause: %w", err)
+	}
+	if simulation.Reverted || simulation.VMError != "" {
+		return nil, fmt.Errorf("unable to deploy contract: %+v", simulation)
+	}
+	gas += simulation.GasUsed
 
-	trx := tx.NewBuilder(tx.TypeLegacy).
+	builder := tx.NewBuilder(tx.TypeLegacy)
+	if best.BaseFeePerGas != nil {
+		builder = tx.NewBuilder(tx.TypeDynamicFee).MaxFeePerGas((*big.Int)(best.BaseFeePerGas))
+	}
+	trx := builder.
 		ChainTag(tag).
-		Clause(tx.NewClause(nil).WithData(bc)).
+		Clause(clause).
 		Expiration(10000).
-		Gas(10_000_000).
+		BlockRef(tx.NewBlockRef(best.Number)).
+		Nonce(datagen.RandUint64()).
+		Gas(gas).
 		Build()
 	trx, err = signer.SignTransaction(trx)
 	if err != nil {
 		return nil, err
 	}
 
-	signerAddr := signer.Address()
-	clauses, err := client.InspectTxClauses(trx, &signerAddr)
-	if err != nil {
-		return nil, err
-	}
-	if len(clauses) != 1 || clauses[0].Reverted || clauses[0].VMError != "" {
-		return nil, fmt.Errorf("unable to deploy contract: %+v", clauses)
-	}
-
 	res, err := client.SendTransaction(trx)
 	if err != nil {
 		return nil, err

thorclient/bind/send.go

@@ -12,13 +12,9 @@ import (
 	"math/big"
 	"time"
 
-	"github.com/ethereum/go-ethereum/common/hexutil"
-	"github.com/ethereum/go-ethereum/common/math"
-
 	"github.com/vechain/thor/v2/api"
 	"github.com/vechain/thor/v2/test/datagen"
 	"github.com/vechain/thor/v2/thor"
-	"github.com/vechain/thor/v2/thorclient"
 	"github.com/vechain/thor/v2/tx"
 )
 
@@ -98,18 +94,11 @@ func (b *SendBuilder) Submit() (*tx.Transaction, error) {
 			return nil, fmt.Errorf("failed to calculate intrinsic gas: %w", err)
 		}
 		caller := b.signer.Address()
-		simulation, err := b.op.contract.client.InspectClauses(
-			&api.BatchCallData{
-				Caller:  &caller,
-				Clauses: api.Clauses{{To: b.op.contract.addr, Data: hexutil.Encode(clause.Data()), Value: (*math.HexOrDecimal256)(clause.Value())}},
-			}, thorclient.Revision("best"))
+		simulation, err := simulateClause(b.op.contract.client, caller, clause)
 		if err != nil {
 			return nil, fmt.Errorf("failed to simulate clauses (%s): %w", b.op.String(), err)
 		}
-		if len(simulation) != 1 {
-			return nil, fmt.Errorf("expected 1 simulation result, got %d", len(simulation))
-		}
-		gas += simulation[0].GasUsed
+		gas += simulation.GasUsed
 		if clause.To() != nil && len(clause.Data()) > 0 {
 			gas += 15_000 // buffer required for OP_CALL
 		}
@@ -134,7 +123,7 @@ func (b *SendBuilder) Submit() (*tx.Transaction, error) {
 	}
 
 	// Build the transaction
-	builder := new(tx.Builder).
+	builder := tx.NewBuilder(txType).
 		Clause(clause).
 		Gas(*opts.Gas).
 		ChainTag(chainTag).

thorclient/bind/simulate.go

@@ -0,0 +1,43 @@
+// Copyright (c) 2025 The VeChainThor developers
+//
+// Distributed under the GNU Lesser General Public License v3.0 software license, see the accompanying
+// file LICENSE or <https://www.gnu.org/licenses/lgpl-3.0.html>
+
+package bind
+
+import (
+	"fmt"
+
+	"github.com/ethereum/go-ethereum/common/hexutil"
+	"github.com/ethereum/go-ethereum/common/math"
+
+	"github.com/vechain/thor/v2/api"
+	"github.com/vechain/thor/v2/thor"
+	"github.com/vechain/thor/v2/thorclient"
+	"github.com/vechain/thor/v2/tx"
+)
+
+// simulateClause simulates the execution of a single clause on top of the best block
+// and returns the simulation result.
+func simulateClause(client *thorclient.Client, caller thor.Address, clause *tx.Clause) (*api.CallResult, error) {
+	var to *thor.Address
+	if clause.To() != nil {
+		addr := *clause.To()
+		to = &addr
+	}
+	sim, err := client.InspectClauses(&api.BatchCallData{
+		Caller: &caller,
+		Clauses: api.Clauses{{
+			To:    to,
+			Data:  hexutil.Encode(clause.Data()),
+			Value: (*math.HexOrDecimal256)(clause.Value()),
+		}},
+	}, thorclient.Revision("best"))
+	if err != nil {
+		return nil, err
+	}
+	if len(sim) != 1 {
+		return nil, fmt.Errorf("expected 1 simulation result, got %d", len(sim))
+	}
+	return sim[0], nil
+}

thorclient/thorclient.go

@@ -991,7 +991,7 @@ func (c *Client) Peers() ([]*api.PeerStats, error) {
 //	}
 //
 //	// Use chain tag when building transaction
-//	tx := tx.NewBuilder(chainTag).
+//	tx := tx.NewBuilder(tx.TypeDynamicFee).
 //		ChainTag(chainTag).
 //		BlockRef(blockRef).
 //		// ... other transaction fields