Testing, Debugging, and Auditing Contracts BDC Practice Questions (Page 7)

Questions 31–35

1. 31foundation · easy

   Which of the following scenarios would most likely require an integration test?

   • AA contract that only reads its own storage variables.
   • BA contract that calls another contract to transfer tokens and then updates its own state.
   • CA contract that emits an event when a function is called.
   • DA contract that has a single function that adds two numbers.
   Reveal Solution Discussion Select an answer first
2. 32foundation · easy

   What is the first step typically performed in a smart contract security audit?

   • AWriting a formal verification proof.
   • BUnderstanding the contract's intended functionality and design.
   • CDeploying the contract to the mainnet.
   • DFixing all identified vulnerabilities.
   Reveal Solution Discussion Select an answer first
4. 33expert · hard

   A developer is writing integration tests for a contract that interacts with a decentralized oracle. The oracle is a live service on a public testnet. The developer wants to ensure the tests are reliable and not flaky. What is the best approach?

   • AUse a mock oracle contract in the test environment to simulate the oracle's responses.
   • BWrite unit tests that mock the oracle's function calls.
   • CUse the live oracle on the testnet and wait for the response.
   • DSkip integration testing and rely on manual testing on the testnet.
   Reveal Solution Discussion Select an answer first
5. 34foundation · easy

   What is the purpose of using `console.log` in a Hardhat test?

   • ATo permanently store data on the blockchain.
   • BTo print debug information to the console during test execution.
   • CTo automatically fix errors in the contract code.
   • DTo increase the gas limit of the test.
   Reveal Solution Discussion Select an answer first
6. 35expert · hard

   A company has a limited budget for a security audit of a DeFi contract that handles user funds. They have received quotes from two audit firms: Firm A offers a comprehensive audit with manual review and automated tools, while Firm B offers a cheaper audit that relies solely on automated tools. The contract has complex logic with multiple external calls. Which approach is more appropriate?

   • AChoose Firm B because automated tools are sufficient for detecting common vulnerabilities and are more cost-effective.
   • BChoose Firm B and supplement with an internal code review by the development team.
   • CSkip the audit and rely on extensive unit and integration tests.
   • DChoose Firm A because manual review is essential for complex contracts with external calls, despite the higher cost.
   Reveal Solution Discussion Select an answer first