feat(solana): simulate executor operation mcms

Simulate the operation of executor ExecuteOperation. Per discussion [here](https://chainlink-core.slack.com/archives/C07NVBK16KS/p1738296756500949?thread_ts=1738215917.353599&cid=C07NVBK16KS), we want to simulate the actual wrapped operation instead of the mcms execute operation.

- Added e2e
- Added unit tests

JIRA: https://smartcontract-it.atlassian.net/browse/DPA-1418

.changeset/cold-gifts-add.md

@@ -0,0 +1,5 @@
+---
+"@smartcontractkit/mcms": minor
+---
+
+feat(solana): simulate executor operation mcms

e2e/tests/solana/simulator.go

@@ -11,6 +11,7 @@ import (
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/gagliardetto/solana-go"
+	"github.com/gagliardetto/solana-go/programs/system"
 
 	"github.com/smartcontractkit/mcms"
 	"github.com/smartcontractkit/mcms/sdk"
@@ -109,3 +110,39 @@ func (s *SolanaTestSuite) TestSimulator_SimulateSetRoot() {
 	}
 	s.Require().NoError(err)
 }
+
+func (s *SolanaTestSuite) TestSimulator_SimulateOperation() {
+	ctx := context.Background()
+
+	recipientAddress, err := solana.NewRandomPrivateKey()
+	s.Require().NoError(err)
+
+	auth, err := solana.PrivateKeyFromBase58(privateKey)
+	s.Require().NoError(err)
+
+	encoder := solanasdk.NewEncoder(s.ChainSelector, 1, false)
+	executor := solanasdk.NewExecutor(encoder, s.SolanaClient, auth)
+	simulator := solanasdk.NewSimulator(executor)
+
+	ix, err := system.NewTransferInstruction(
+		1*solana.LAMPORTS_PER_SOL,
+		auth.PublicKey(),
+		recipientAddress.PublicKey()).ValidateAndBuild()
+	s.Require().NoError(err)
+
+	ixData, err := ix.Data()
+	s.Require().NoError(err)
+
+	tx, err := solanasdk.NewTransaction(solana.SystemProgramID.String(), ixData, nil, ix.Accounts(), "System", []string{})
+	s.Require().NoError(err)
+
+	op := types.Operation{
+		Transaction:   tx,
+		ChainSelector: s.ChainSelector,
+	}
+	metadata := types.ChainMetadata{
+		MCMAddress: s.MCMProgramID.String(),
+	}
+	err = simulator.SimulateOperation(ctx, metadata, op)
+	s.Require().NoError(err)
+}

sdk/solana/simulator.go

@@ -2,6 +2,8 @@ package solana
 
 import (
 	"context"
+	"encoding/json"
+	"errors"
 	"fmt"
 	"time"
 
@@ -45,14 +47,26 @@ func (s *Simulator) SimulateSetRoot(
 func (s *Simulator) SimulateOperation(
 	ctx context.Context, metadata types.ChainMetadata, operation types.Operation,
 ) error {
-	s.instructions = []solana.Instruction{}
-	nonce := uint32(0)
-	proof := []common.Hash{}
-	_, err := s.executor.ExecuteOperation(ctx, metadata, nonce, proof, operation)
-	if err != nil {
-		return err
+	var additionalFields AdditionalFields
+	if err := json.Unmarshal(operation.Transaction.AdditionalFields, &additionalFields); err != nil {
+		return fmt.Errorf("unable to unmarshal additional fields: %w", err)
 	}
 
+	toProgramID, _, err := ParseContractAddress(operation.Transaction.To)
+	if errors.Is(err, ErrInvalidContractAddressFormat) {
+		var pkerr error
+		toProgramID, pkerr = solana.PublicKeyFromBase58(operation.Transaction.To)
+		if pkerr != nil {
+			return fmt.Errorf("unable to parse the 'To' address: %w", err)
+		}
+	}
+
+	s.instructions = append(s.instructions, solana.NewInstruction(
+		toProgramID,
+		additionalFields.Accounts,
+		operation.Transaction.Data,
+	))
+
 	return s.simulate(ctx)
 }
 

sdk/solana/simulator_test.go

@@ -3,10 +3,13 @@ package solana
 import (
 	"context"
 	"errors"
+	"fmt"
 	"testing"
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/gagliardetto/solana-go"
+	"github.com/gagliardetto/solana-go/programs/system"
+	cselectors "github.com/smartcontractkit/chain-selectors"
 	"github.com/stretchr/testify/require"
 
 	"github.com/smartcontractkit/mcms/sdk/solana/mocks"
@@ -78,3 +81,98 @@ func TestSimulator_SimulateSetRoot(t *testing.T) {
 		})
 	}
 }
+
+func TestSimulator_SimulateOperation(t *testing.T) {
+	t.Parallel()
+
+	auth, err := solana.NewRandomPrivateKey()
+	require.NoError(t, err)
+
+	selector := cselectors.SOLANA_DEVNET.Selector
+
+	testWallet := solana.NewWallet()
+	ix, err := system.NewTransferInstruction(20*solana.LAMPORTS_PER_SOL, auth.PublicKey(), testWallet.PublicKey()).ValidateAndBuild()
+	require.NoError(t, err)
+
+	data, err := ix.Data()
+	require.NoError(t, err)
+
+	tx, err := NewTransaction(solana.SystemProgramID.String(), data, nil, ix.Accounts(), "solana-testing", []string{})
+	require.NoError(t, err)
+
+	tests := []struct {
+		name          string
+		givenOP       types.Operation
+		setupMocks    func(t *testing.T, client *mocks.JSONRPCClient)
+		expectedError string
+	}{
+		{
+			name: "success: SimulateOperation",
+			givenOP: types.Operation{
+				Transaction:   tx,
+				ChainSelector: types.ChainSelector(selector),
+			},
+			setupMocks: func(t *testing.T, m *mocks.JSONRPCClient) {
+				t.Helper()
+				mockSolanaSimulateTransaction(t, m, 50, nil, nil)
+			},
+		},
+		{
+			name: "error: invalid additional fields",
+			givenOP: types.Operation{
+				Transaction: types.Transaction{
+					AdditionalFields: []byte("invalid"),
+				},
+				ChainSelector: types.ChainSelector(selector),
+			},
+			setupMocks: func(t *testing.T, m *mocks.JSONRPCClient) {
+				t.Helper()
+			},
+			expectedError: "unable to unmarshal additional fields: invalid character 'i' looking for beginning of value",
+		},
+		{
+			name: "error: block hash fetch failed",
+			givenOP: types.Operation{
+				Transaction:   tx,
+				ChainSelector: types.ChainSelector(selector),
+			},
+			setupMocks: func(t *testing.T, m *mocks.JSONRPCClient) {
+				t.Helper()
+				mockSolanaSimulateTransaction(t, m, 50, errors.New("block hash error"), nil)
+			},
+			expectedError: "unable to simulate instruction: block hash error",
+		},
+		{
+			name: "failure: SimulateTransaction error",
+			givenOP: types.Operation{
+				Transaction:   tx,
+				ChainSelector: types.ChainSelector(selector),
+			},
+			setupMocks: func(t *testing.T, client *mocks.JSONRPCClient) {
+				t.Helper()
+				mockSolanaSimulateTransaction(t, client, 50, nil, errors.New("SimulateTransaction error"))
+			},
+			expectedError: "SimulateTransaction error",
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+
+			executor, client := newTestExecutor(t, auth, testChainSelector)
+			simulator := NewSimulator(executor)
+
+			tt.setupMocks(t, client)
+
+			err = simulator.SimulateOperation(context.Background(), types.ChainMetadata{
+				MCMAddress: fmt.Sprintf("%s.%s", testMCMProgramID.String(), testPDASeed),
+			}, tt.givenOP)
+
+			if tt.expectedError != "" {
+				require.ErrorContains(t, err, tt.expectedError)
+			} else {
+				require.NoError(t, err)
+			}
+		})
+	}
+}