Hooks in Mocha

• before() — Runs once before the first test case in the block
• beforeEach() — Runs before each test case
• afterEach() — Runs after each test case
• after() — Runs once after the last test case in the block

• Sequence of Hooks
• before() -> beforeEach() -> test() -> afterEach() -> after()

Achieving 100% Coverage

• Positive test
• Test that code behaves as expected when valid data is given.
• Negative tests
• Test that code behaves as expected when invalid data is given.

Solidity code coverage tools

• solidity-coverage(Truffle) - https://github.com/sc-forks/solidity-coverage
• solidity-coverage(Hardhat) - https://github.com/sc-forks/solidity-coverage/blob/master/HARDHAT_README.md

Static Analysis : tools

• Solidity Static Analysis - Remix Plugin
• sFuzz - fuzzer to find common vulnerabilities
• SmartCheck - sc vulnerabilities and bugs detector
• slither - Solidity static analyzer
• echidna - rapid sc fuzzer
• Securify - Solidity security static analyzer

Solidity Static Analysis - Remix Plugin

• Debug the code without execution.
• Ensures proper coding standards, best practices, syntax errors,etc.

Solidity Static Analysis - Remix Plugin

Solidity Static Analysis - Remix Plugin

Solidity Static Analysis - Remix Plugin

• False Positive on infinite gas for dynamic arrays such as string

Static Analysis : Echidna

• Property testing to generate malicious inputs that break smart contracts
• Generates inputs tailored to code
• Optional corpus collection, mutation and coverage guidance to find deeper bugs
• Powered by Slither to extract useful information before the fuzzing campaign

Static Analysis : Echidna

• Automatic testcase minimization for quick triage
• Seamless integration into the development workflow
• Maximum gas usage reporting of the fuzzing campaign
• Support for a complex contract initialization with Etheno and Truffle

Dynamic Analysis

• Analysis is performed by executing the program
• Unit testing is a type of dynamic analysis

Dynamic Analysis

• Truffle tests
• Hardhat unit tests
• Vertigo - Mutation testing for Ethereum smart contracts
• Unit Testing Plugin - Remix Plugin