Transaction Helpers

Sending Transactions

The TransactionHelpers trait provides convenient methods for sending instructions and analyzing results.

Send a Single Instruction

use litesvm_utils::{LiteSVM, Signer, TestHelpers, TransactionHelpers};
use solana_sdk::{native_token::LAMPORTS_PER_SOL, system_instruction};

#[test]
fn test_send_instruction() {
    let mut svm = LiteSVM::new();

    let alice = svm.create_funded_account(10 * LAMPORTS_PER_SOL).unwrap();
    let bob = svm.create_funded_account(0).unwrap();

    // Create a transfer instruction
    let transfer_ix = system_instruction::transfer(
        &alice.pubkey(),
        &bob.pubkey(),
        LAMPORTS_PER_SOL,
    );

    // Send and get result (returns Result<TransactionResult, TransactionError>)
    let result = svm.send_instruction(transfer_ix, &[&alice]).unwrap();

    // Assert it succeeded
    result.assert_success();
}

Send Multiple Instructions

use litesvm_utils::{LiteSVM, Signer, TestHelpers, TransactionHelpers};
use solana_sdk::{native_token::LAMPORTS_PER_SOL, system_instruction};

#[test]
fn test_send_multiple_instructions() {
    let mut svm = LiteSVM::new();

    let alice = svm.create_funded_account(10 * LAMPORTS_PER_SOL).unwrap();
    let bob = svm.create_funded_account(0).unwrap();
    let carol = svm.create_funded_account(0).unwrap();

    // Create multiple transfer instructions
    let instructions = vec![
        system_instruction::transfer(&alice.pubkey(), &bob.pubkey(), LAMPORTS_PER_SOL),
        system_instruction::transfer(&alice.pubkey(), &carol.pubkey(), LAMPORTS_PER_SOL),
    ];

    // Send all in one transaction
    let result = svm.send_instructions(&instructions, &[&alice]).unwrap();
    result.assert_success();
}

TransactionResult

The send_instruction and send_instructions methods return a TransactionResult that wraps the transaction metadata with useful testing utilities.

Assert Success

use litesvm_utils::{LiteSVM, Signer, TestHelpers, TransactionHelpers};
use solana_sdk::{native_token::LAMPORTS_PER_SOL, system_instruction};

#[test]
fn test_assert_success() {
    let mut svm = LiteSVM::new();

    let alice = svm.create_funded_account(10 * LAMPORTS_PER_SOL).unwrap();
    let bob = svm.create_funded_account(0).unwrap();

    let ix = system_instruction::transfer(&alice.pubkey(), &bob.pubkey(), LAMPORTS_PER_SOL);
    let result = svm.send_instruction(ix, &[&alice]).unwrap();

    // Panics with detailed logs if the transaction failed
    result.assert_success();
}

assert_success() will panic with the full transaction logs if the transaction failed, making debugging much easier.

Assert Failure

use litesvm_utils::{LiteSVM, Signer, TestHelpers, TransactionHelpers};
use solana_sdk::{native_token::LAMPORTS_PER_SOL, system_instruction};

#[test]
fn test_assert_failure() {
    let mut svm = LiteSVM::new();

    let alice = svm.create_funded_account(1 * LAMPORTS_PER_SOL).unwrap();
    let bob = svm.create_funded_account(0).unwrap();

    // Try to transfer more than Alice has
    let ix = system_instruction::transfer(
        &alice.pubkey(),
        &bob.pubkey(),
        100 * LAMPORTS_PER_SOL, // Alice only has 1 SOL
    );
    let result = svm.send_instruction(ix, &[&alice]).unwrap();

    // This should fail
    result.assert_failure();
}

Assert Specific Error

use litesvm_utils::{LiteSVM, Signer, TestHelpers, TransactionHelpers};
use solana_sdk::{native_token::LAMPORTS_PER_SOL, system_instruction};

#[test]
fn test_assert_error() {
    let mut svm = LiteSVM::new();

    let alice = svm.create_funded_account(1 * LAMPORTS_PER_SOL).unwrap();
    let bob = svm.create_funded_account(0).unwrap();

    let ix = system_instruction::transfer(
        &alice.pubkey(),
        &bob.pubkey(),
        100 * LAMPORTS_PER_SOL,
    );
    let result = svm.send_instruction(ix, &[&alice]).unwrap();

    // Assert a specific error message is present
    result.assert_error("insufficient lamports");
}

Assert Error Code

For custom program errors, you can assert on the error code:

// Assert a specific custom error code
result.assert_error_code(6000); // Custom error code from your program

Assert Anchor Error

For Anchor programs, assert on error names:

// Assert an Anchor-specific error
result.assert_anchor_error("InsufficientFunds");

Inspecting Transactions

Check Transaction Logs

use litesvm_utils::{LiteSVM, Signer, TestHelpers, TransactionHelpers};
use solana_sdk::{native_token::LAMPORTS_PER_SOL, system_instruction};

#[test]
fn test_check_logs() {
    let mut svm = LiteSVM::new();

    let alice = svm.create_funded_account(10 * LAMPORTS_PER_SOL).unwrap();
    let bob = svm.create_funded_account(0).unwrap();

    let ix = system_instruction::transfer(&alice.pubkey(), &bob.pubkey(), LAMPORTS_PER_SOL);
    let result = svm.send_instruction(ix, &[&alice]).unwrap();

    // Check if a specific message is in the logs
    if result.has_log("Transfer") {
        println!("Found transfer log!");
    }

    // Find a log matching a pattern
    if let Some(log) = result.find_log("Program") {
        println!("Found log: {}", log);
    }

    // Get all logs
    let logs = result.logs();
    for log in logs {
        println!("{}", log);
    }
}

Print Logs for Debugging

use litesvm_utils::{LiteSVM, Signer, TestHelpers, TransactionHelpers};
use solana_sdk::{native_token::LAMPORTS_PER_SOL, system_instruction};

#[test]
fn test_print_logs() {
    let mut svm = LiteSVM::new();

    let alice = svm.create_funded_account(10 * LAMPORTS_PER_SOL).unwrap();
    let bob = svm.create_funded_account(0).unwrap();

    let ix = system_instruction::transfer(&alice.pubkey(), &bob.pubkey(), LAMPORTS_PER_SOL);
    let result = svm.send_instruction(ix, &[&alice]).unwrap();

    // Print formatted logs for debugging
    result.print_logs();
}

Check Compute Units

use litesvm_utils::{LiteSVM, Signer, TestHelpers, TransactionHelpers};
use solana_sdk::{native_token::LAMPORTS_PER_SOL, system_instruction};

#[test]
fn test_compute_units() {
    let mut svm = LiteSVM::new();

    let alice = svm.create_funded_account(10 * LAMPORTS_PER_SOL).unwrap();
    let bob = svm.create_funded_account(0).unwrap();

    let ix = system_instruction::transfer(&alice.pubkey(), &bob.pubkey(), LAMPORTS_PER_SOL);
    let result = svm.send_instruction(ix, &[&alice]).unwrap();

    let compute_units = result.compute_units();
    println!("Compute units consumed: {}", compute_units);

    // Assert compute usage is within expected bounds
    assert!(compute_units < 10_000, "Transaction used too many compute units");
}

Monitoring compute units is useful for optimization. Solana limits transactions to 1.4M compute units, and higher usage costs more.

Complete Example

Here's a comprehensive example demonstrating transaction helpers:

use litesvm_utils::{AssertionHelpers, LiteSVM, Signer, TestHelpers, TransactionHelpers};
use solana_sdk::{native_token::LAMPORTS_PER_SOL, system_instruction};

#[test]
fn test_transaction_workflow() {
    let mut svm = LiteSVM::new();

    // Setup accounts
    let alice = svm.create_funded_account(10 * LAMPORTS_PER_SOL).unwrap();
    let bob = svm.create_funded_account(0).unwrap();

    // Test successful transfer
    let transfer_ix = system_instruction::transfer(
        &alice.pubkey(),
        &bob.pubkey(),
        2 * LAMPORTS_PER_SOL,
    );

    let result = svm.send_instruction(transfer_ix, &[&alice]).unwrap();

    // Verify success
    result.assert_success();

    // Check compute usage
    let cu = result.compute_units();
    println!("Transfer used {} compute units", cu);

    // Verify balances
    svm.assert_sol_balance(&bob.pubkey(), 2 * LAMPORTS_PER_SOL);

    // Test expected failure
    let bad_transfer = system_instruction::transfer(
        &alice.pubkey(),
        &bob.pubkey(),
        100 * LAMPORTS_PER_SOL, // More than Alice has
    );

    let fail_result = svm.send_instruction(bad_transfer, &[&alice]).unwrap();
    fail_result.assert_failure();

    // Print logs for debugging
    fail_result.print_logs();

    println!("Transaction workflow test passed!");
}

Error Types

The TransactionError enum provides structured error information:

Variant	Description
`ExecutionFailed(String)`	Transaction execution failed with message
`BuildError(String)`	Failed to build the transaction
`AssertionFailed(String)`	An assertion on the result failed

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