Blockchain Testing & Security Validation

Create thorough test suites that validate smart contract functionality, security properties, and edge cases. Use modern testing frameworks to ensure code reliability before deployment.

Examples

Foundry Test Structure

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;

import "forge-std/Test.sol";
import "../contracts/Token.sol";

contract TokenTest is Test {
    Token token;
    address alice = address(0x1);
    address bob = address(0x2);
    
    function setUp() public {
        token = new Token();
        token.mint(alice, 1000 ether);
    }
    
    function testTransfer() public {
        vm.prank(alice);
        token.transfer(bob, 100 ether);
        assertEq(token.balanceOf(bob), 100 ether);
    }
}

Testing Reverts

function testTransferInsufficientBalance() public {
    vm.prank(alice);
    vm.expectRevert("Insufficient balance");
    token.transfer(bob, 2000 ether);
}

Fuzz Testing

function testTransferFuzz(address to, uint256 amount) public {
    vm.assume(to != address(0));
    vm.assume(amount <= token.balanceOf(alice));
    
    uint256 aliceBalanceBefore = token.balanceOf(alice);
    vm.prank(alice);
    token.transfer(to, amount);
    
    assertEq(token.balanceOf(alice), aliceBalanceBefore - amount);
}

Invariant Testing

function invariant_totalSupplyConstant() public {
    assertEq(token.totalSupply(), INITIAL_SUPPLY);
}

function invariant_reserveBacking() public {
    assertTrue(address(reserve).balance >= token.totalSupply());
}

Guidelines

Test Coverage Strategy

• Achieve 100% line coverage for critical functions
• Test all revert conditions explicitly
• Include edge cases (zero amounts, max values)
• Test interactions between contracts
• Validate event emissions

Testing Patterns

• Use setUp() for test initialization
• One assertion per test for clarity
• Descriptive test function names
• Group related tests in contracts
• Use test helpers for complex setups

Security Testing

• Test for reentrancy vulnerabilities
• Validate access control thoroughly
• Check for integer overflow/underflow
• Test delegate call interactions
• Verify storage collision resistance

Performance Testing

• Measure gas consumption
• Benchmark against similar contracts
• Test with realistic data sizes
• Profile storage vs memory usage
• Optimize based on test results

Integration Testing

• Test contract deployment sequences
• Validate upgrade mechanisms
• Test cross-contract calls
• Verify oracle integrations
• Simulate mainnet conditions with forks