There may be scenarios where you need to build out transactions that involve multiple program types and assets; this can be done by instantiating a ScriptTransactionRequest . This class allows you to a append multiple program types and assets to a single transaction.
Consider the following script that transfers multiple assets to a contract:
script;
use std::asset::transfer;
fn main(
contract_address: b256,
asset_a: AssetId,
amount_asset_a: u64,
asset_b: AssetId,
amount_asset_b: u64,
) -> bool {
let wrapped_contract = ContractId::from(contract_address);
let contract_id = Identity::ContractId(wrapped_contract);
transfer(contract_id, asset_a, amount_asset_a);
transfer(contract_id, asset_b, amount_asset_b);
true
} This script can be executed by creating a ScriptTransactionRequest , appending the resource and contract inputs/outputs and then sending the transaction, as follows:
// 1. Create a script transaction using the script binary
const request = new ScriptTransactionRequest({
...defaultTxParams,
gasLimit: 3_000_000,
script: ScriptTransferToContract.bytecode,
});
// 2. Instantiate the script main arguments
const scriptArguments = [
contract.id.toB256(),
{ bits: ASSET_A },
new BN(1000),
{ bits: ASSET_B },
new BN(500),
];
// 3. Populate the script data and add the contract input and output
request
.setData(ScriptTransferToContract.abi, scriptArguments)
.addContractInputAndOutput(contract.id);
// 4. Get the transaction resources
const quantities = [
coinQuantityfy([1000, ASSET_A]),
coinQuantityfy([500, ASSET_B]),
];
// 5. Calculate the transaction fee
const txCost = await wallet.getTransactionCost(request, { quantities });
request.gasLimit = txCost.gasUsed;
request.maxFee = txCost.maxFee;
await wallet.fund(request, txCost);
// 6. Send the transaction
const tx = await wallet.sendTransaction(request);
await tx.waitForResult();
const contractFinalBalanceAssetA = await contract.getBalance(ASSET_A);
const contractFinalBalanceAssetB = await contract.getBalance(ASSET_B);For a full example, see below:
import { BN, ScriptTransactionRequest, coinQuantityfy } from 'fuels';
import { ASSET_A, ASSET_B, launchTestNode } from 'fuels/test-utils';
import { EchoValuesFactory } from '../typegend/contracts/EchoValuesFactory';
import { ScriptTransferToContract } from '../typegend/scripts/ScriptTransferToContract';
using launched = await launchTestNode({
contractsConfigs: [{ factory: EchoValuesFactory }],
});
const {
contracts: [contract],
wallets: [wallet],
} = launched;
const defaultTxParams = {
gasLimit: 10000,
};
// 1. Create a script transaction using the script binary
const request = new ScriptTransactionRequest({
...defaultTxParams,
gasLimit: 3_000_000,
script: ScriptTransferToContract.bytecode,
});
// 2. Instantiate the script main arguments
const scriptArguments = [
contract.id.toB256(),
{ bits: ASSET_A },
new BN(1000),
{ bits: ASSET_B },
new BN(500),
];
// 3. Populate the script data and add the contract input and output
request
.setData(ScriptTransferToContract.abi, scriptArguments)
.addContractInputAndOutput(contract.id);
// 4. Get the transaction resources
const quantities = [
coinQuantityfy([1000, ASSET_A]),
coinQuantityfy([500, ASSET_B]),
];
// 5. Calculate the transaction fee
const txCost = await wallet.getTransactionCost(request, { quantities });
request.gasLimit = txCost.gasUsed;
request.maxFee = txCost.maxFee;
await wallet.fund(request, txCost);
// 6. Send the transaction
const tx = await wallet.sendTransaction(request);
await tx.waitForResult();
const contractFinalBalanceAssetA = await contract.getBalance(ASSET_A);
const contractFinalBalanceAssetB = await contract.getBalance(ASSET_B);