Solidity Coverage: Code Coverage for Solidity Testing


Code coverage for Solidity testing

coverage example


  • Hardhat >= 2.11.0


$ yarn add solidity-coverage --dev

Require the plugin in hardhat.config.js (Hardhat docs)


Or, if you are using TypeScript, add this to your hardhat.config.ts:

import 'solidity-coverage'



npx hardhat coverage [command-options]

Command Options

Option Example Description
testfiles--testfiles "test/registry/*.ts"Test file(s) to run. (Globs must be enclosed by quotes and use [globby matching patterns][38])
solcoverjs--solcoverjs ./../.solcover.jsRelative path from working directory to config. Useful for monorepo packages that share settings. (Path must be "./" prefixed)
network--network developmentUse network settings defined in the Hardhat config
temp[*][14]--temp build:warning: Caution :warning: Path to a disposable folder to store compilation artifacts in. Useful when your test setup scripts include hard-coded paths to a build directory. [More...][14]
matrix--matrixGenerate a JSON object that maps which mocha tests hit which lines of code. (Useful as an input for some fuzzing, mutation testing and fault-localization algorithms.) [More...][39]

* Advanced use

Config Options

Additional options can be specified in a .solcover.js config file located in the root directory of your project.


module.exports = {
  skipFiles: ['Routers/EtherRouter.sol']
Option Type Default Description
silentBooleanfalseSuppress logging output
skipFilesArray['Migrations.sol']Array of contracts or folders (with paths expressed relative to the contracts directory) that should be skipped when doing instrumentation.
measureStatementCoveragebooleantrueComputes statement (in addition to line) coverage. [More...][34]
measureFunctionCoveragebooleantrueComputes function coverage. [More...][34]
measureModifierCoveragebooleantrueComputes each modifier invocation as a code branch. [More...][34]
modifierWhitelistString[][]List of modifier names (ex: "onlyOwner") to exclude from branch measurement. (Useful for modifiers which prepare something instead of acting as a gate.))
matrixOutputPathString./testMatrix.jsonRelative path to write test matrix JSON object to. [More...][39]
mochaJsonOutputPathString./mochaOutput.jsonRelative path to write mocha JSON reporter object to. [More...][39]
abiOutputPathString./humanReadableAbis.jsonRelative path to write diff-able ABI data to
istanbulFolderString./coverageFolder location for Istanbul coverage reports.
istanbulReporterArray['html', 'lcov', 'text', 'json'][Istanbul coverage reporters][2]
mochaObject{ }[Mocha options][3] to merge into existing mocha config. grep and invert are useful for skipping certain tests under coverage using tags in the test descriptions.
coverageContractsTempString.coverage_contractsTemporary folder location for instrumented contracts - Note that this directory will automatically be deleted when coverage completes.
onServerReady[*][14]Function Hook run after server is launched, before the tests execute. Useful if you need to use the Oraclize bridge or have setup scripts which rely on the server's availability. [More...][23]
onPreCompile[*][14]Function Hook run after filesystem and compiler configuration is applied, before the compiler is run. Can be used with the other hooks to be able to generate coverage reports on non-standard / customized directory structures, as well as contracts with absolute import paths. [More...][23]
onCompileComplete[*][14]Function Hook run after compilation completes, before tests are run. Useful if you have secondary compilation steps or need to modify built artifacts. [More...][23]
onTestsComplete[*][14]Function Hook run after the tests complete, before Istanbul reports are generated. [More...][23]
onIstanbulComplete[*][14]Function Hook run after the Istanbul reports are generated, before the ganache server is shut down. Useful if you need to clean resources up. [More...][23]
configureYulOptimizerBooleanfalse(Experimental) Setting to true should resolve "stack too deep" compiler errors in large projects using ABIEncoderV2
solcOptimizerDetailsObjectundefined(Experimental) Must be used in combination with configureYulOptimizer. Allows you configure solc's [optimizer details][1001]. Useful if the default remedy for stack-too-deep errors doesn't work in your case (See FAQ below).
clientObjectrequire("ganache-core")Ganache only: useful if you need a specific ganache version
providerOptionsObject{ }Ganache only: [ganache-core options][1]

* Advanced use

Viewing the reports:

  • You can find the Istanbul reports written to the ./coverage/ folder generated in your root directory.


Solidity-coverage's core methods and many utilities are available as an API.

const CoverageAPI = require('solidity-coverage/api');

Documentation available here.

Detecting solidity-coverage from another task

If you're writing another plugin or task, it can be helpful to detect whether coverage is running or not. The coverage plugin sets a boolean variable on the globally injected hardhat environment object for this purpose.



Common problems & questions:

Example reports

Contribution Guidelines

Contributions are welcome! If you're opening a PR that adds features or options please consider writing full unit tests for them. (We've built simple fixtures for almost everything and are happy to add some for your case if necessary).

Set up the development environment with:

$ git clone
$ yarn


Download details:

Author: sc-forks

License: MIT license

#solidity #smartcontract #blockchain 

Solidity Coverage: Code Coverage for Solidity Testing
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