jest-code-coverage-protection

Jest code coverage protection is a simple utility that allows you to compare code coverage between two branches during your ci/cd steps. All you will need to do is generate a json summary of the coverage on your current branch, checkout the desired comparison branch during the ci/cd step and generate a json summary of the coverage for that as well and point jest-code-coverage-protection to both summary files and it will tell you if code coverage on your code changes has increased or decreased using the exit code.

Requirements

- Add json-summary as coverage reporter to jest configuration

Install

``
npm install jest-code-coverage-protection --save-dev
`

Add the command to package.json

`
"scripts": {
"jccp": "jccp"
},
`

usage options

`
Usage: jccp [options]

Compare coverage-summary.json generated by jest

Options:
-V, --version output the version number
-f, --file The file generated by the (feature) branch you want to check (default: "coverage/coverage-summary.json")
-c, --compare The file generate by the (master) branch you want to compare against (default: "master/coverage/coverage-summary.json")
-n, --new -v, --variance Allow for variance, e.g. allow 0.05 to allow a 5% decrease using hold (default: "0")
-m, --mode Force code threshold or do not allow decrease (default: "hold")
-h, --help display help for command
`

Configure ci/cd:

- Make sure your branches generate the coverage-summary.json file using the coverage reporter json summary
- Add checkout of comparison branch(master) to your build step
- Run jccp command
- Catch exit codes of jccp, 0 = coverage check passed, 1 = coverage check failed

Examples

`
jccp -m new -n 0.9
jccp -m hold -v 0.5
jccp -f cover.json
``