Aztec Testing

Aztec Testing Skill

You are an expert in testing Aztec smart contracts. Help users write comprehensive tests using Aztec's TestEnvironment and debugging test failures.

Testing Framework Overview

Aztec provides a Noir-native testing framework using TestEnvironment that allows you to:

• Deploy contracts in a simulated environment
• Call private and public functions
• Verify state changes
• Test access control
• Simulate multiple users

Test Setup

Basic Test Structure

use aztec::{
    protocol::address::AztecAddress,
    test::helpers::test_environment::TestEnvironment,
};

#[test]
unconstrained fn test_example() {
    // Setup
    let mut env = TestEnvironment::new();
    let owner = env.create_light_account();

    // Deploy
    let initializer = MyContract::interface().constructor(args);
    let contract_address = env.deploy("MyContract").with_public_initializer(owner, initializer);

    // Act - call private function
    env.call_private(owner, MyContract::at(contract_address).some_function(args));

    // Assert - view public state
    let result = env.view_public(MyContract::at(contract_address).view_function());
    assert(result == expected);
}

Account Types

// Light account - fast, limited features (use for most tests)
let owner = env.create_light_account();

// Contract account - full features including authwit support (slower)
let owner = env.create_contract_account();

Deployment Options

// Deploy with public initializer
let address = env.deploy("MyContract").with_public_initializer(owner, initializer);

// Deploy with private initializer
let address = env.deploy("MyContract").with_private_initializer(owner, initializer);

// Deploy without initializer
let address = env.deploy("MyContract").without_initializer();

Common Testing Patterns

Testing Private Functions

#[test]
unconstrained fn test_private_transfer() {
    let mut env = TestEnvironment::new();
    let alice = env.create_light_account();
    let bob = env.create_light_account();

    // Deploy and setup
    let contract_address = deploy_token(&mut env, alice);

    // Mint to alice first
    env.call_private(alice, Token::at(contract_address).mint_private(alice, 100));

    // Transfer from alice to bob
    env.call_private(alice, Token::at(contract_address).transfer(bob, 50));

    // Verify balances using simulate_utility for unconstrained reads
    let alice_balance = env.simulate_utility(Token::at(contract_address).balance_of_private(alice));
    let bob_balance = env.simulate_utility(Token::at(contract_address).balance_of_private(bob));

    assert(alice_balance == 50);
    assert(bob_balance == 50);
}

Testing Public Functions

#[test]
unconstrained fn test_public_mint() {
    let mut env = TestEnvironment::new();
    let admin = env.create_light_account();
    let user = env.create_light_account();

    let contract_address = deploy_token(&mut env, admin);

    // Admin mints tokens
    env.call_public(admin, Token::at(contract_address).mint_public(user, 1000));

    // Verify balance
    let balance = env.view_public(Token::at(contract_address).balance_of_public(user));
    assert(balance == 1000);
}

Testing Access Control

#[test(should_fail)]
unconstrained fn test_unauthorized_mint() {
    let mut env = TestEnvironment::new();
    let admin = env.create_light_account();
    let attacker = env.create_light_account();

    let contract_address = deploy_token(&mut env, admin);

    // Non-admin tries to mint - should fail
    env.call_public(attacker, Token::at(contract_address).mint_public(attacker, 1000));
}

Testing Private <> Public Communication

#[test]
unconstrained fn test_public_to_private() {
    let mut env = TestEnvironment::new();
    let user = env.create_light_account();

    let contract_address = deploy_token(&mut env, user);

    // Give user some public tokens
    env.call_public(user, Token::at(contract_address).mint_public(user, 100));

    // Move tokens from public to private
    env.call_private(user, Token::at(contract_address).public_to_private(50));

    // Verify balances in both domains
    let public_balance = env.view_public(Token::at(contract_address).balance_of_public(user));
    let private_balance = env.simulate_utility(Token::at(contract_address).balance_of_private(user));

    assert(public_balance == 50);
    assert(private_balance == 50);
}

Testing Best Practices

1. Test Isolation

• Each test should be independent
• Don't rely on state from other tests
• Use fresh TestEnvironment for each test

2. Test Coverage

• Happy path scenarios
• Edge cases (zero amounts, max values)
• Access control violations
• Invalid inputs

3. Descriptive Test Names

#[test]
fn test_transfer_succeeds_with_sufficient_balance() { }

#[test(should_fail)]
fn test_transfer_fails_with_insufficient_balance() { }

4. Helper Functions

Create reusable helpers for common setup:

unconstrained fn deploy_token(env: &mut TestEnvironment, admin: AztecAddress) -> AztecAddress {
    let initializer = Token::interface().constructor(admin);
    env.deploy("Token").with_public_initializer(admin, initializer)
}

Debugging Test Failures

Common Issues

1. "Not authorized" errors

   • Check if you've called env.impersonate(correct_user)
   • Verify the user has the required role

2. State not updating

   • Ensure you're using the right context (.private() vs .public())
   • Check that enqueued calls are being processed

3. Note not found

   • Make sure notes were created before consumption
   • Verify the note owner is correct

4. Assertion failures

   • Add print statements to debug values
   • Check for off-by-one errors
   • Verify expected vs actual values

Running Tests

# Run all tests
aztec test

# Run specific test
aztec test --test-name test_transfer

# Run with verbose output
aztec test --show-output