mollusk-helper

A simplified wrapper around mollusk-svm for easier Solana program testing with atomic transaction support.

Features

• Unified API: All functionality accessible through MolluskContextHelper
• Atomic Transactions: Run multiple instructions with snapshot/restore semantics
• SPL Token Support: Built-in helpers for mints, token accounts, and transfers
• Keypair Management: Store and retrieve keypairs by name for signing
• Add Custom Programs: Dynamically add programs after context creation

Default Programs

The following programs are included by default:

Installation

Add to your Cargo.toml:

[dev-dependencies]
mollusk-helper = { git = "https://github.com/ohaddahan/mollusk-helper" }

Quick Start

use mollusk_helper::prelude::*;

// Create context with your program
let elf = std::fs::read("path/to/your/program.so").unwrap();
let ctx = MolluskContextHelper::new(&program_id, &elf);

// Or without a custom program (for testing system/token operations)
let ctx = MolluskContextHelper::new_without_program();

// Fund accounts
ctx.fund_account(&alice, 1_000_000);
ctx.fund_account(&bob, 0);

// Execute single instruction
ctx.transfer_sol(&alice, &bob, 500_000)?;

Adding Custom Programs

You can add programs dynamically after context creation:

let mut ctx = MolluskContextHelper::new_without_program();

// Add program with default loader (v3/upgradeable)
let elf = std::fs::read("path/to/program.so").unwrap();
ctx.add_program(&program_id, &elf);

// Or specify the loader version
ctx.add_program_with_loader(&program_id, &elf, ProgramLoader::V2);

Constructor Variants

// With custom program (loader v3 by default)
let ctx = MolluskContextHelper::new(&program_id, &elf);

// With custom timestamp
let ctx = MolluskContextHelper::new_with_timestamp(&program_id, &elf, unix_timestamp);

// With specific loader
let ctx = MolluskContextHelper::new_with_loader(&program_id, &elf, ProgramLoader::V2);

// Full control
let ctx = MolluskContextHelper::new_with_options(
    &program_id,
    &elf,
    ProgramLoader::V3,
    unix_timestamp,
);

// Without custom program
let ctx = MolluskContextHelper::new_without_program();

Atomic Transactions

Run multiple instructions as an atomic unit. If any instruction fails, all changes are rolled back:

let result = ctx
    .transaction()
    .add_instruction(transfer_ix_1)
    .add_instruction(transfer_ix_2)
    .execute()?;

// On success: both transfers applied
// On failure: neither transfer applied (state restored)

Transaction Methods

• execute() - Stops on first failure, rolls back all changes
• execute_allow_failures() - Runs all instructions, rolls back if any failed
• dry_run() - Executes but always restores original state

Token Operations

// Create mint and token account
ctx.create_mint(&mint, &authority, 9);
ctx.create_token_account(&token_account, &mint, &owner, 0);

// Mint tokens
ctx.mint_to(&mint, &token_account, &authority, 1_000_000)?;

// Check balance
let balance = ctx.get_token_balance(&token_account)?;

// Transfer tokens
ctx.transfer_tokens(&source, &destination, &authority, 500_000)?;

Keypair Management

let keypair = Keypair::new();
ctx.store_keypair("signer", keypair)?;

let pubkey = ctx.get_keypair_pubkey("signer")?;
let signature = ctx.sign_with("signer", &message)?;

Program ID Constants

MolluskContextHelper::system_program()
MolluskContextHelper::token_program()
MolluskContextHelper::token_2022_program()
MolluskContextHelper::associated_token_program()
MolluskContextHelper::memo_program()
MolluskContextHelper::memo_v1_program()
MolluskContextHelper::address_lookup_table_program()
MolluskContextHelper::compute_budget_program()
MolluskContextHelper::native_mint()

API Reference

Constructors

Program Management

Instruction Processing

Account Management

Token Helpers

License

MIT