solidity-coverage

Code coverage for Solidity testing

• For more details about what this is, how it works and potential limitations, see the accompanying article.
• solidity-coverage is Solcover

Requirements

• Hardhat >= 2.11.0

Install

$ yarn add solidity-coverage --dev

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

require('solidity-coverage')

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

import 'solidity-coverage'

Resources:

• 0.8.0 release notes

Run

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)
sources	--sources myFolder or --sources myFile.sol	Path to single folder or file to target for coverage. Path is relative to Hardhat's paths.sources (usually contracts/)
solcoverjs	--solcoverjs ./../.solcover.js	Relative path from working directory to config. Useful for monorepo packages that share settings. (Path must be "./" prefixed)
temp*	--temp build	⚠️ Caution ⚠️ 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...
matrix	--matrix	Generate 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...

^* Advanced use

Config Options

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

Example:

module.exports = {
  skipFiles: ['Routers/EtherRouter.sol']
};

Option	Type	Default	Description
silent	Boolean	false	Suppress logging output
skipFiles	Array	['Migrations.sol']	Array of contracts or folders (with paths expressed relative to the contracts directory) that should be skipped when doing instrumentation.
measureStatementCoverage	boolean	true	Computes statement (in addition to line) coverage. More...
measureFunctionCoverage	boolean	true	Computes function coverage. More...
measureModifierCoverage	boolean	true	Computes each modifier invocation as a code branch. More...
modifierWhitelist	String[]	[]	List of modifier names (ex: "onlyOwner") to exclude from branch measurement. (Useful for modifiers which prepare something instead of acting as a gate.))
matrixOutputPath	String	./testMatrix.json	Relative path to write test matrix JSON object to. More...
mochaJsonOutputPath	String	./mochaOutput.json	Relative path to write mocha JSON reporter object to. More...
abiOutputPath	String	./humanReadableAbis.json	Relative path to write diff-able ABI data to
istanbulFolder	String	./coverage	Folder location for Istanbul coverage reports.
istanbulReporter	Array	['html', 'lcov', 'text', 'json']	Istanbul coverage reporters
mocha	Object	{ }	Mocha options to merge into existing mocha config. grep and invert are useful for skipping certain tests under coverage using tags in the test descriptions.
coverageContractsTemp	String	.coverage_contracts	Temporary folder location for instrumented contracts - Note that this directory will automatically be deleted when coverage completes.
onServerReady*	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...
onPreCompile*	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...
onCompileComplete*	Function		Hook run after compilation completes, before tests are run. Useful if you have secondary compilation steps or need to modify built artifacts. More...
onTestsComplete*	Function		Hook run after the tests complete, before Istanbul reports are generated. More...
onIstanbulComplete*	Function		Hook run after the Istanbul reports are generated, before the coverage task completes. Useful if you need to clean resources up. More...
configureYulOptimizer	Boolean	false	(Experimental) Setting to true should resolve "stack too deep" compiler errors in large projects using ABIEncoderV2
solcOptimizerDetails	Object	undefined	(Experimental) Must be used in combination with configureYulOptimizer. Allows you configure solc's optimizer details. Useful if the default remedy for stack-too-deep errors doesn't work in your case (See FAQ below).

^* Advanced use

Viewing the reports:

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

API

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.

hre.__SOLIDITY_COVERAGE_RUNNING === true

FAQ

Common problems & questions:

• Running in CI
• Running out of gas
• Running out of time
• Running out of stack (Stack too deep)
• Running out of memory
• Running in parallel (in CI)
• Running coverage threshold checks

Example reports

• metacoin (Istanbul HTML)
• openzeppelin-solidity(Coveralls)

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 https://github.com/sc-forks/solidity-coverage.git
$ yarn