Blockchain Development Frameworks (Truffle, Hardhat) BDC Practice Questions (Page 5)

Questions 21–25

1. 21application · medium

   A developer is debugging a Solidity contract in Hardhat. The contract reverts with a custom error, but the stack trace does not show the exact line where the revert occurs. Which Hardhat feature should the developer use to get more detailed debugging information?

   • ARun the test with the `--verbose` flag to enable detailed stack traces.
   • BUse `hardhat console` to step through the contract execution line by line.
   • CEnable Solidity stack traces in `hardhat.config.js` by setting `solidity: { version: '0.8.17', settings: { debug: { revertStrings: 'debug' } } }`.
   • DUse the `--debug` flag when running the deploy script to get a full trace.
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2. 22expert · hard

   A team is deploying a contract to a public testnet using Hardhat. They have a deployment script that works locally, but when they run it with --network testnet, it fails with a nonce error. What is the most likely cause?

   • AThe network configuration in hardhat.config.js is missing the chainId.
   • BThe contract has a constructor that requires an argument, and the script does not pass it.
   • CThe deployment script is using a different account than the one funded with test ETH.
   • DThe account has pending transactions from a previous deployment that have not been mined, causing the nonce to be out of sync.
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4. 23foundation · easy

   In Hardhat, which command runs the test suite?

   • Anpx hardhat verify
   • Bnpx hardhat run test
   • Cnpx hardhat check
   • Dnpx hardhat test
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5. 24foundation · easy

   Which command compiles all Solidity contracts in a Truffle project?

   • Atruffle compile
   • Btruffle build
   • Ctruffle migrate
   • Dtruffle test
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6. 25application · medium

   A team wants to verify their smart contract source code on Etherscan after deployment. They are using Hardhat. Which plugin should they install and how should they configure it?

   • AUse the built-in Hardhat verify command without installing any plugin.
   • BInstall @nomiclabs/hardhat-etherscan and add the Etherscan API key to the hardhat.config.js file.
   • CInstall hardhat-deploy and use its built-in verify command without an API key.
   • DInstall @truffle/plugin-verify and add the Etherscan API key to truffle-config.js.
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