Aptos Move Testing

Unit Testing in Move

#[test]
fun test_basic_functionality() {
    // Test code here
    assert!(condition, ERROR_CODE);
}

#[test(account = @0x1)]
fun test_with_signer(account: &signer) {
    // Test with signer parameter
}

#[test]
#[expected_failure(abort_code = ERROR_CODE)]
fun test_expected_failure() {
    // Code that should fail
}

Test Attributes

• #[test] - Basic test function
• #[test(param = @address)] - Test with named parameters (signers/addresses)
• #[test_only] - Functions/modules only compiled in test mode
• #[expected_failure] - Test should abort
• #[expected_failure(abort_code = N)] - Test should abort with specific code

Process

When a user asks about Move testing:

1. Identify Testing Need

Common scenarios:
- Writing unit tests for new functions
- Testing resource operations (move_to, move_from, borrow_global)
- Verifying error conditions and abort codes
- Integration testing with multiple modules
- Formal verification with Move Prover
- Debugging test failures
- Improving test coverage

2. Determine Test Type

Unit Tests:

• Test individual functions in isolation
• Mock dependencies
• Fast execution
• Use #[test] attribute

Integration Tests:

• Test module interactions
• Test complete workflows
• Use multiple signers
• Test state changes

Formal Verification:

• Use Move Prover
• Write specifications
• Verify invariants
• Prove correctness mathematically

3. Provide Testing Solution

Structure your response:

• Test strategy - what to test and why
• Code example - working test code
• Setup - any required test fixtures or helper functions
• Assertions - what to verify
• Edge cases - corner cases to consider
• Commands - how to run the tests

Testing Patterns

Pattern 1: Resource Testing

#[test_only]
use std::signer;

#[test(account = @0x123)]
fun test_resource_creation(account: &signer) {
    let addr = signer::address_of(account);

    // Create resource
    create_resource(account);

    // Verify resource exists
    assert!(exists<MyResource>(addr), ERROR_RESOURCE_NOT_FOUND);

    // Verify resource state
    let resource = borrow_global<MyResource>(addr);
    assert!(resource.value == expected_value, ERROR_INVALID_STATE);
}

Pattern 2: Error Condition Testing

#[test]
#[expected_failure(abort_code = ERROR_INSUFFICIENT_BALANCE)]
fun test_insufficient_balance() {
    // Setup account with low balance
    // Attempt operation that should fail
    transfer(from, to, amount_too_large);
}

Pattern 3: Multi-Signer Testing

#[test(alice = @0x123, bob = @0x456)]
fun test_transfer(alice: &signer, bob: &signer) {
    let alice_addr = signer::address_of(alice);
    let bob_addr = signer::address_of(bob);

    // Setup initial state
    initialize(alice);
    initialize(bob);

    // Perform transfer
    transfer(alice, bob_addr, 100);

    // Verify balances
    assert!(get_balance(alice_addr) == 900, ERROR_INVALID_BALANCE);
    assert!(get_balance(bob_addr) == 100, ERROR_INVALID_BALANCE);
}

Pattern 4: Test-Only Helpers

#[test_only]
module test_helpers {
    use std::signer;

    public fun setup_account(account: &signer): address {
        let addr = signer::address_of(account);
        // Common setup logic
        addr
    }

    public fun create_test_token(account: &signer, amount: u64) {
        // Create tokens for testing
    }
}

Move Prover Integration

Specification Syntax

spec module {
    // Module-level invariants
    invariant forall addr: address:
        exists<Balance>(addr) ==> global<Balance>(addr).value >= 0;
}

spec transfer {
    // Pre-conditions
    requires sender_balance >= amount;
    requires sender != recipient;

    // Post-conditions
    ensures global<Balance>(sender).value == old(global<Balance>(sender).value) - amount;
    ensures global<Balance>(recipient).value == old(global<Balance>(recipient).value) + amount;

    // Abort conditions
    aborts_if sender_balance < amount;
}

Running Move Prover

# Verify all specs in package
aptos move prove

# Verify specific module
aptos move prove --filter MyModule

# Verbose output
aptos move prove --verbose

Test Commands

Basic Testing

# Run all tests in package
aptos move test

# Run specific test
aptos move test --filter test_name

# Run tests with coverage
aptos move test --coverage

# Run with gas profiling
aptos move test --gas

# Verbose output
aptos move test --verbose

Test Output Interpretation

Running Move unit tests
[ PASS    ] 0x1::my_module::test_success
[ FAIL    ] 0x1::my_module::test_failure
[ TIMEOUT ] 0x1::my_module::test_slow

Error: Assertion failed
   ┌── my_module.move:42:9 ───
   │
42 │         assert!(balance == 100, ERROR_INVALID_BALANCE);
   │         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Debugging Strategies

1. Add Debug Prints (Test Only)

#[test_only]
use std::debug;

#[test]
fun test_with_debug() {
    debug::print(&b"Starting test");
    debug::print(&value);
    // Test logic
}

2. Break Down Complex Tests

// Instead of one large test
#[test]
fun test_complex_workflow() {
    setup();
    step1();
    step2();
    step3();
    verify();
}

// Break into multiple tests
#[test]
fun test_step1() { /* ... */ }

#[test]
fun test_step2() { /* ... */ }

#[test]
fun test_step3() { /* ... */ }

3. Use Specific Abort Codes

const ERROR_INVALID_AMOUNT: u64 = 1;
const ERROR_INSUFFICIENT_BALANCE: u64 = 2;
const ERROR_UNAUTHORIZED: u64 = 3;

// In code
assert!(amount > 0, ERROR_INVALID_AMOUNT);

// In test
#[expected_failure(abort_code = ERROR_INVALID_AMOUNT)]
fun test_zero_amount() { /* ... */ }

Test Coverage Best Practices

What to Test

✅ Critical Paths:

• Main business logic
• State transitions
• Access control
• Resource management

✅ Error Conditions:

• Invalid inputs
• Insufficient permissions
• Resource not found
• Arithmetic overflow

✅ Edge Cases:

• Zero values
• Maximum values
• Empty collections
• Boundary conditions

✅ Invariants:

• Total supply conservation
• Balance constraints
• Ownership rules

Coverage Goals

Aim for:
- 100% of public functions
- 100% of abort conditions
- All state transitions
- All access control checks

Common Testing Patterns

Setup/Teardown Pattern

#[test_only]
fun setup_test_env(account: &signer): TestContext {
    initialize_module(account);
    create_test_resources(account);
    TestContext { /* ... */ }
}

#[test(account = @0x1)]
fun test_feature(account: &signer) {
    let ctx = setup_test_env(account);
    // Use ctx
    // No teardown needed (Move tests are isolated)
}

Parameterized Testing

#[test_only]
fun verify_transfer_amount(amount: u64, expected_result: bool) {
    if (expected_result) {
        transfer(sender, receiver, amount);
    } else {
        // Should fail
    }
}

#[test]
fun test_valid_amounts() {
    verify_transfer_amount(1, true);
    verify_transfer_amount(100, true);
    verify_transfer_amount(1000, true);
}

#[test]
#[expected_failure]
fun test_invalid_amounts() {
    verify_transfer_amount(0, false);
}

State Verification

#[test]
fun test_state_consistency(account: &signer) {
    let addr = signer::address_of(account);

    // Initial state
    let before = get_state(addr);

    // Perform operation
    perform_operation(account);

    // Verify state changes
    let after = get_state(addr);
    assert!(after.field1 == before.field1 + delta, ERROR_STATE);
}

Integration with CI/CD

GitHub Actions Example