def test_example(direct_vm, direct_deploy, direct_alice, direct_bob):
    # direct_vm      — VMContext with cheatcodes
    # direct_deploy  — deploy a contract file
    # direct_alice   — test address
    # direct_bob     — test address
    pass

All fixtures: direct_vm, direct_deploy, direct_alice, direct_bob, direct_charlie, direct_owner, direct_accounts

Basic Test Pattern

def test_set_and_get(direct_vm, direct_deploy, direct_alice):
    contract = direct_deploy("contracts/my_contract.py")
    direct_vm.sender = direct_alice

    contract.set_data("hello")

    result = contract.get_data(direct_alice)
    assert result == "hello"

Mocking Web Requests

For contracts that call gl.nondet.web.get():

import json

def test_with_web_mock(direct_vm, direct_deploy, direct_alice):
    contract = direct_deploy("contracts/my_contract.py")
    direct_vm.sender = direct_alice

    # Pattern: regex matching on URL
    direct_vm.mock_web(
        r".*api\.example\.com/prices.*",
        {"status": 200, "body": '{"price": 42.5}'},
    )

    contract.update_price("ETH/USD")
    assert contract.get_price("ETH/USD") == 42.5

Full mock format (when you need headers/method control)

direct_vm.mock_web(
    r"api\.example\.com/data",
    {
        "response": {
            "status": 200,
            "headers": {},
            "body": json.dumps({"key": "value"}).encode()
        },
        "method": "GET"
    }
)

Mocking LLM Responses

For contracts that call gl.nondet.exec_prompt():

direct_vm.mock_llm(
    r".*Extract the match result.*",  # Regex on prompt text
    json.dumps({"score": "2:1", "winner": 1}),
)

Clearing Mocks

direct_vm.clear_mocks()  # Reset between test scenarios

VMContext Cheatcodes

# Set transaction sender
direct_vm.sender = direct_alice

# Set native value (wei)
direct_vm.value = 1000000000000000000  # 1 ETH

# Expect a revert
with direct_vm.expect_revert("Insufficient balance"):
    contract.withdraw(1000)

# Temporary sender change
with direct_vm.prank(direct_bob):
    contract.method()  # Called as bob

# Snapshot and restore state
snap_id = direct_vm.snapshot()
contract.modify_state()
direct_vm.revert(snap_id)  # State restored

# Set account balance
direct_vm.deal(direct_alice, 1000000000000000000)

# Time travel
direct_vm.warp("2024-06-01T12:00:00Z")

Test Organization

tests/direct/
├── conftest.py           # Shared fixtures and mock helpers
├── test_<feature>.py     # Tests per feature/method
└── test_<feature>_web.py # Tests requiring web/LLM mocks

What to Test in Direct Mode

Category	Example
State transitions	Create → read back → verify fields
Validation / reverts	Invalid inputs, unauthorized callers
Access control	Owner-only methods, role checks
Edge cases	Empty state, boundary values, overflow
Web/LLM parsing	Mock responses → verify extraction logic

Common Patterns

Testing access control

def test_only_owner(direct_vm, direct_deploy, direct_alice, direct_bob):
    contract = direct_deploy("contracts/my_contract.py")

    direct_vm.sender = direct_alice
    contract.create_item("item_1")

    direct_vm.sender = direct_bob
    with direct_vm.expect_revert("Only owner"):
        contract.delete_item("item_1")

Testing state transitions

def test_state_flow(direct_vm, direct_deploy, direct_alice):
    contract = direct_deploy("contracts/my_contract.py")
    direct_vm.sender = direct_alice

    contract.create_item("item_1")
    assert contract.get_item("item_1")["status"] == "pending"

    contract.approve_item("item_1")
    assert contract.get_item("item_1")["status"] == "approved"

Reusable mock helpers (conftest.py)

import json

def mock_price_api(direct_vm, pair: str, price: float):
    """Mock a price API response."""
    direct_vm.mock_web(
        rf".*api\.example\.com/prices/{pair}.*",
        {"status": 200, "body": json.dumps({"price": price})},
    )

Tips

Always direct_vm.sender = ... before calling write methods
Use --json flag on genvm-lint check before writing tests to understand the contract's interface
Direct mode runs leader function only — validator logic is not exercised. Use integration tests for full consensus validation.

direct-tests

Direct Mode Tests

Running Tests

Fixtures