Solidity Development

Solidity Development Skill

Master Solidity smart contract development with design patterns, testing strategies, and production best practices.

Quick Start

# Invoke this skill for Solidity development
Skill("solidity-development", topic="patterns", solidity_version="0.8.24")

Topics Covered

1. Language Features (0.8.x)

Modern Solidity essentials:

• Data Types: Value, reference, mappings
• Functions: Visibility, modifiers, overloading
• Inheritance: Diamond problem, C3 linearization
• Custom Errors: Gas-efficient error handling

2. Design Patterns

Battle-tested patterns:

• CEI: Checks-Effects-Interactions
• Factory: Contract deployment patterns
• Proxy: Upgradeable contracts
• Access Control: RBAC, Ownable

3. Testing

Comprehensive test strategies:

• Unit Tests: Foundry, Hardhat
• Fuzz Testing: Property-based testing
• Invariant Testing: System-wide properties
• Fork Testing: Mainnet simulation

4. Upgradability

Safe upgrade patterns:

• UUPS: Self-upgrading proxy
• Transparent: Admin separation
• Beacon: Shared implementation
• Diamond: Multi-facet

Code Examples

CEI Pattern

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.24;

contract SecureVault {
    mapping(address => uint256) public balances;

    error InsufficientBalance();
    error TransferFailed();

    function withdraw(uint256 amount) external {
        // 1. CHECKS
        if (balances[msg.sender] < amount) revert InsufficientBalance();

        // 2. EFFECTS
        balances[msg.sender] -= amount;

        // 3. INTERACTIONS
        (bool ok,) = msg.sender.call{value: amount}("");
        if (!ok) revert TransferFailed();
    }
}

Factory Pattern

contract TokenFactory {
    event TokenCreated(address indexed token, address indexed owner);

    function createToken(
        string memory name,
        string memory symbol
    ) external returns (address) {
        Token token = new Token(name, symbol, msg.sender);
        emit TokenCreated(address(token), msg.sender);
        return address(token);
    }
}

Foundry Test

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.24;

import "forge-std/Test.sol";

contract VaultTest is Test {
    Vault vault;
    address alice = makeAddr("alice");

    function setUp() public {
        vault = new Vault();
        vm.deal(alice, 10 ether);
    }

    function test_Deposit() public {
        vm.prank(alice);
        vault.deposit{value: 1 ether}();

        assertEq(vault.balances(alice), 1 ether);
    }

    function testFuzz_Withdraw(uint256 amount) public {
        amount = bound(amount, 0.01 ether, 10 ether);

        vm.startPrank(alice);
        vault.deposit{value: amount}();
        vault.withdraw(amount);
        vm.stopPrank();

        assertEq(vault.balances(alice), 0);
    }

    function test_RevertWhen_InsufficientBalance() public {
        vm.prank(alice);
        vm.expectRevert(Vault.InsufficientBalance.selector);
        vault.withdraw(1 ether);
    }
}

Pattern Reference

Common Pitfalls

Troubleshooting

"Stack too deep"

// Solution 1: Use struct
struct Params { uint256 a; uint256 b; uint256 c; }

// Solution 2: Block scoping
{ uint256 temp = x + y; }

// Solution 3: Internal function
function _helper(uint256 a) internal { }

"Contract size exceeds limit"

# Check contract sizes
forge build --sizes

Solutions: Split into libraries, use Diamond pattern.

Security Checklist

• [ ] CEI pattern on all withdrawals
• [ ] Access control on admin functions
• [ ] Input validation (zero address, bounds)
• [ ] Reentrancy guards on external calls
• [ ] Event emission for state changes
• [ ] Custom errors for gas efficiency

CLI Commands

# Development workflow
forge init                    # New project
forge build                   # Compile
forge test -vvv               # Run tests
forge coverage                # Coverage report
forge fmt                     # Format code
forge snapshot                # Gas snapshot

Cross-References

• Bonded Agent: 03-solidity-expert
• Related Skills: ethereum-development, smart-contract-security

Version History

Solidity Development Guide

Overview

This guide provides comprehensive documentation for the solidity-development skill in the custom-plugin-blockchain plugin.

Category: General

Quick Start

Prerequisites

• Familiarity with general concepts
• Development environment set up
• Plugin installed and configured

Basic Usage

# Invoke the skill
claude "solidity-development - [your task description]"

# Example
claude "solidity-development - analyze the current implementation"

Core Concepts

Key Principles

1. Consistency - Follow established patterns 2. Clarity - Write readable, maintainable code 3. Quality - Validate before deployment

Best Practices

• Always validate input data
• Handle edge cases explicitly
• Document your decisions
• Write tests for critical paths

Common Tasks

Task 1: Basic Implementation

# Example implementation pattern
def implement_solidity_development(input_data):
    """
    Implement solidity-development functionality.

    Args:
        input_data: Input to process

    Returns:
        Processed result
    """
    # Validate input
    if not input_data:
        raise ValueError("Input required")

    # Process
    result = process(input_data)

    # Return
    return result

Task 2: Advanced Usage

For advanced scenarios, consider:

• Configuration customization via assets/config.yaml
• Validation using scripts/validate.py
• Integration with other skills

Troubleshooting

Common Issues

Related Resources

• SKILL.md - Skill specification
• config.yaml - Configuration options
• validate.py - Validation script

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Last updated: 2025-12-30

Solidity Development Patterns

Design Patterns

Pattern 1: Input Validation

Always validate input before processing:

def validate_input(data):
    if data is None:
        raise ValueError("Data cannot be None")
    if not isinstance(data, dict):
        raise TypeError("Data must be a dictionary")
    return True

Pattern 2: Error Handling

Use consistent error handling:

try:
    result = risky_operation()
except SpecificError as e:
    logger.error(f"Operation failed: {e}")
    handle_error(e)
except Exception as e:
    logger.exception("Unexpected error")
    raise

Pattern 3: Configuration Loading

Load and validate configuration:

import yaml

def load_config(config_path):
    with open(config_path) as f:
        config = yaml.safe_load(f)
    validate_config(config)
    return config

Anti-Patterns to Avoid

❌ Don't: Swallow Exceptions

# BAD
try:
    do_something()
except:
    pass

✅ Do: Handle Explicitly

# GOOD
try:
    do_something()
except SpecificError as e:
    logger.warning(f"Expected error: {e}")
    return default_value

Category-Specific Patterns: General

Recommended Approach

1. Start with the simplest implementation 2. Add complexity only when needed 3. Test each addition 4. Document decisions

Common Integration Points

• Configuration: assets/config.yaml
• Validation: scripts/validate.py
• Documentation: references/GUIDE.md

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Pattern library for solidity-development skill