Code coverage for Jest built on top of Jasmine

Question

Is there a way to have code coverage in the JavaScript Jest testing framework that is built on top of Jasmine  The internal framework does not print out the code coverage it gets  I ve also tried using Istanbul  blanket  and JSCover  but none of them work

User · Answer

This works for me    quot jest quot          quot collectCoverage quot   true       quot coverageReporters quot     quot json quot    quot html quot           quot scripts quot          quot test quot    quot jest  --coverage quot        Run  yarn npm test

User · Answer

I had the same issue and I fixed it as below   install yarn npm install --save-dev yarn install jest-cli npm install --save-dev jest-cli add this to the package json  quot jest-coverage quot    quot yarn run jest -- --coverage quot   After you write the tests  run the command npm run jest-coverage  This will create a coverage folder in the root directory   coverage icov-report index html has the HTML view of the code coverage

User · Answer

When using Jest 21 2 1  I can see code coverage at the command line and create a coverage directory by passing --coverage to the Jest script  Below are some examples   I tend to install Jest locally  in which case the command might look like this    npx jest --coverage  I assume  though haven t confirmed   that this would also work if I installed Jest globally   jest --coverage  The very sparse docs are here  When I navigated into the coverage lcov-report directory I found an index html file that could be loaded into a browser  It included the information printed at the command line  plus additional information and some graphical output

User · Answer

Configure your package json file          test    jest --coverage       Now run   yarn test   All the test will start running and you will get the report

User · Answer

UPDATE  7 20 2018 - Added links and updated name for coverageReporters   UPDATE  8 14 2017 - This answer is totally outdated  Just look at the Jest docs now  They have official support and documentation about how to do this    hankhsiao has got a forked repo where Istanbul is working with Jest   Add this to your dev dependencies    devDependencies           jest-cli    git   github com hankhsiao jest git       Also make sure coverage is enabled in your package json jest entry and you can also specify formats you want    The html is pretty bad ass      jest           collectCoverage   true        coverageReporters     json    html         See Jest documentation for coverageReporters  default is    json    lcov    text     Or add --coverage when you invoke jest

User · Answer

If you are having trouble with --coverage not working it may also be due to having coverageReporters enabled without  text  or  text-summary  being added  From the docs   Note  Setting this option overwrites the default values  Add  text  or  text-summary  to see a coverage summary in the console output   Source

User · Answer

Try Chutzpah  I have just used it  And I blogged about it on how to integrate in Visual Studio  This is how I did code coverage with Chutzpah  Code Coverage with Chutzpah

User · Answer

If you are using the NestJS framework  you can get code coverage using this command  npm run test cov

User · Answer

Jan 2019  Jest version 23 6 For anyone looking into this question recently especially if testing using npm or yarn directly Currently  you don t have to change the configuration options As per Jest official website  you can do the following to generate coverage reports  1- For npm  You must put -- before passing the --coverage argument of Jest npm test -- --coverage  if you try invoking the --coverage directly without the -- it won t work 2- For yarn  You can pass the --coverage argument of jest directly yarn test --coverage

User · Answer

Check the latest Jest  v 0 22   https   github com facebook jest  The Facebook team adds the Istanbul code coverage output as part of the coverage report and you can use it directly   After executing Jest  you can get a coverage report in the console and under the root folder set by Jest  you will find the coverage report in JSON and HTML format   FYI  if you install from npm  you might not get the latest version  so try the GitHub first and make sure the coverage is what you need

[javascript] Code coverage for Jest built on top of Jasmine

Examples related to javascript

Examples related to jestjs