ethclient, internal/ethapi: allow eth_call with overrides

This publishes the previously internal ethapi.StateOverrides type as
well as adds the methods CallContractWithOverrides and
PendingCallContractWithOverrides to ethclient.Client.

#22197

eth/tracers/api_test.go

@@ -29,6 +29,7 @@ import (
 	"testing"
 	"time"
 
+	"github.com/ethereum/go-ethereum"
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/ethereum/go-ethereum/consensus"
@@ -345,7 +346,7 @@ func TestOverridenTraceCall(t *testing.T) {
 			config: &TraceCallConfig{
 				Tracer: &tracer,
 				StateOverrides: &ethapi.StateOverride{
-					randomAccounts[0].addr: ethapi.OverrideAccount{Balance: newRPCBalance(new(big.Int).Mul(big.NewInt(1), big.NewInt(params.Ether)))},
+					randomAccounts[0].addr: ethereum.OverrideAccount{Balance: newRPCBalance(new(big.Int).Mul(big.NewInt(1), big.NewInt(params.Ether)))},
 				},
 			},
 			expectErr: nil,
@@ -398,7 +399,7 @@ func TestOverridenTraceCall(t *testing.T) {
 			config: &TraceCallConfig{
 				Tracer: &tracer,
 				StateOverrides: &ethapi.StateOverride{
-					randomAccounts[2].addr: ethapi.OverrideAccount{
+					randomAccounts[2].addr: ethereum.OverrideAccount{
 						Code:      newRPCBytes(common.Hex2Bytes("6080604052348015600f57600080fd5b506004361060285760003560e01c80638381f58a14602d575b600080fd5b60336049565b6040518082815260200191505060405180910390f35b6000548156fea2646970667358221220eab35ffa6ab2adfe380772a48b8ba78e82a1b820a18fcb6f59aa4efb20a5f60064736f6c63430007040033")),
 						StateDiff: newStates([]common.Hash{{}}, []common.Hash{common.BigToHash(big.NewInt(123))}),
 					},

ethclient/ethclient.go

@@ -473,19 +473,37 @@ func (ec *Client) PendingTransactionCount(ctx context.Context) (uint, error) {
 // case the code is taken from the latest known block. Note that state from very old
 // blocks might not be available.
 func (ec *Client) CallContract(ctx context.Context, msg ethereum.CallMsg, blockNumber *big.Int) ([]byte, error) {
+	return ec.CallContractWithOverrides(ctx, msg, blockNumber, nil)
+}
+
+// PendingCallContract executes a message call transaction using the EVM.
+// The state seen by the contract call is the pending state.
+func (ec *Client) PendingCallContract(ctx context.Context, msg ethereum.CallMsg) ([]byte, error) {
+	return ec.PendingCallContractWithOverrides(ctx, msg, nil)
+}
+
+// CallContractWithOverrides executes a message call transaction, which is directly executed in the VM
+// of the node, but never mined into the blockchain.
+//
+// blockNumber selects the block height at which the call runs. It can be nil, in which
+// case the code is taken from the latest known block. Note that state from very old
+// blocks might not be available.
+//
+// overrides specifies accounts whose state will be overridden prior to execution.
+func (ec *Client) CallContractWithOverrides(ctx context.Context, msg ethereum.CallMsg, blockNumber *big.Int, overrides ethereum.StateOverride) ([]byte, error) {
 	var hex hexutil.Bytes
-	err := ec.c.CallContext(ctx, &hex, "eth_call", toCallArg(msg), toBlockNumArg(blockNumber))
+	err := ec.c.CallContext(ctx, &hex, "eth_call", toCallArg(msg), toBlockNumArg(blockNumber), overrides)
 	if err != nil {
 		return nil, err
 	}
 	return hex, nil
 }
 
-// PendingCallContract executes a message call transaction using the EVM.
-// The state seen by the contract call is the pending state.
-func (ec *Client) PendingCallContract(ctx context.Context, msg ethereum.CallMsg) ([]byte, error) {
+// PendingCallContractWithOverrides executes a message call transaction using the EVM.
+// The state seen by the contract call is the pending state after account overrides have been applied.
+func (ec *Client) PendingCallContractWithOverrides(ctx context.Context, msg ethereum.CallMsg, overrides ethereum.StateOverride) ([]byte, error) {
 	var hex hexutil.Bytes
-	err := ec.c.CallContext(ctx, &hex, "eth_call", toCallArg(msg), "pending")
+	err := ec.c.CallContext(ctx, &hex, "eth_call", toCallArg(msg), "pending", overrides)
 	if err != nil {
 		return nil, err
 	}

ethclient/ethclient_test.go

@@ -28,6 +28,7 @@ import (
 
 	"github.com/ethereum/go-ethereum"
 	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/ethereum/go-ethereum/consensus/ethash"
 	"github.com/ethereum/go-ethereum/core"
 	"github.com/ethereum/go-ethereum/core/rawdb"
@@ -263,6 +264,9 @@ func TestEthClient(t *testing.T) {
 		"TestCallContract": {
 			func(t *testing.T) { testCallContract(t, client) },
 		},
+		"TestCallContractWithOverrides": {
+			func(t *testing.T) { testCallContractWithOverrides(t, client) },
+		},
 		"TestAtFunctions": {
 			func(t *testing.T) { testAtFunctions(t, client) },
 		},
@@ -492,12 +496,49 @@ func testCallContract(t *testing.T, client *rpc.Client) {
 	if _, err := ec.CallContract(context.Background(), msg, big.NewInt(1)); err != nil {
 		t.Fatalf("unexpected error: %v", err)
 	}
-	// PendingCallCOntract
+	// PendingCallContract
 	if _, err := ec.PendingCallContract(context.Background(), msg); err != nil {
 		t.Fatalf("unexpected error: %v", err)
 	}
 }
 
+func testCallContractWithOverrides(t *testing.T, client *rpc.Client) {
+	ec := NewClient(client)
+
+	nonExistentAccount := common.Address{1}
+
+	msg := ethereum.CallMsg{
+		From:  nonExistentAccount,
+		To:    &common.Address{},
+		Gas:   21000,
+		Value: big.NewInt(1),
+	}
+
+	// CallContract should fail due to lack of funds
+	if _, err := ec.CallContract(context.Background(), msg, big.NewInt(1)); err == nil {
+		t.Fatalf("expected error sending from empty account")
+	}
+	// PendingCallContract should fail due to lack of funds
+	if _, err := ec.PendingCallContract(context.Background(), msg); err == nil {
+		t.Fatalf("expected error sending from empty account")
+	}
+
+	// Override
+	overrides := make(ethereum.StateOverride)
+	balance := new(*hexutil.Big)
+	*balance = (*hexutil.Big)(big.NewInt(1))
+	overrides[nonExistentAccount] = ethereum.OverrideAccount{Balance: balance}
+
+	// CallContractWithOverrides should succeed with overridden balance
+	if _, err := ec.CallContractWithOverrides(context.Background(), msg, big.NewInt(1), overrides); err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	// PendingCallContractWithOverrides should succeed with overridden balance
+	if _, err := ec.PendingCallContractWithOverrides(context.Background(), msg, overrides); err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+}
+
 func testAtFunctions(t *testing.T, client *rpc.Client) {
 	ec := NewClient(client)
 	// send a transaction for some interesting pending status

interfaces.go

@@ -23,6 +23,7 @@ import (
 	"math/big"
 
 	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/ethereum/go-ethereum/core/types"
 )
 
@@ -133,6 +134,23 @@ type ContractCaller interface {
 	CallContract(ctx context.Context, call CallMsg, blockNumber *big.Int) ([]byte, error)
 }
 
+// OverrideAccount indicates the overriding fields of account during the execution
+// of a message call.
+// Note, state and stateDiff can't be specified at the same time. If state is
+// set, message execution will only use the data in the given state. Otherwise
+// if statDiff is set, all diff will be applied first and then execute the call
+// message.
+type OverrideAccount struct {
+	Nonce     *hexutil.Uint64              `json:"nonce"`
+	Code      *hexutil.Bytes               `json:"code"`
+	Balance   **hexutil.Big                `json:"balance"`
+	State     *map[common.Hash]common.Hash `json:"state"`
+	StateDiff *map[common.Hash]common.Hash `json:"stateDiff"`
+}
+
+// StateOverride is the collection of overridden accounts.
+type StateOverride map[common.Address]OverrideAccount
+
 // FilterQuery contains options for contract log filtering.
 type FilterQuery struct {
 	BlockHash *common.Hash     // used by eth_getLogs, return logs only from block with this hash

internal/ethapi/api.go

@@ -25,6 +25,7 @@ import (
 	"time"
 
 	"github.com/davecgh/go-spew/spew"
+	"github.com/ethereum/go-ethereum"
 	"github.com/ethereum/go-ethereum/accounts"
 	"github.com/ethereum/go-ethereum/accounts/abi"
 	"github.com/ethereum/go-ethereum/accounts/keystore"
@@ -804,22 +805,8 @@ func (s *PublicBlockChainAPI) GetStorageAt(ctx context.Context, address common.A
 	return res[:], state.Error()
 }
 
-// OverrideAccount indicates the overriding fields of account during the execution
-// of a message call.
-// Note, state and stateDiff can't be specified at the same time. If state is
-// set, message execution will only use the data in the given state. Otherwise
-// if statDiff is set, all diff will be applied first and then execute the call
-// message.
-type OverrideAccount struct {
-	Nonce     *hexutil.Uint64              `json:"nonce"`
-	Code      *hexutil.Bytes               `json:"code"`
-	Balance   **hexutil.Big                `json:"balance"`
-	State     *map[common.Hash]common.Hash `json:"state"`
-	StateDiff *map[common.Hash]common.Hash `json:"stateDiff"`
-}
-
 // StateOverride is the collection of overridden accounts.
-type StateOverride map[common.Address]OverrideAccount
+type StateOverride ethereum.StateOverride
 
 // Apply overrides the fields of specified accounts into the given state.
 func (diff *StateOverride) Apply(state *state.StateDB) error {