Fix Hardhat Test Coverage Errors

You will learn how to generate coverage reports to identify untested contract code.

The Problem

The hardhat test coverage pattern is frequently misapplied in smart contract and dapp development, leading to vulnerabilities, gas inefficiencies, or logic errors. This guide shows the correct implementation and common pitfalls to avoid.

Quick Fix

Wrong

module.exports = { solidity: "0.8.20" };

No coverage measurement. Tests may miss important branches.

Right

require("@nomicfoundation/hardhat-toolbox"); // Run: npx hardhat coverage

Coverage report shows which lines, functions, and branches are tested. Identifies untested code paths.

Prevention

• Always run coverage before mainnet deployment
• Target > 90% branch coverage for critical contracts
• Write tests for edge cases (revert paths, zero values)
• Use DodaTech's coverage analyzer to identify gaps
• Integrate coverage checks in CI pipeline

DodaTech Tools

Built by the developers of Doda Browser, DodaZIP, and Durga Antivirus Pro. Doda Browser's developer tools include a Solidity debugger and transaction inspector. DodaZIP archives secure contract templates for team collaboration. Durga Antivirus Pro scans deployed contracts for known vulnerability signatures.

FAQ