koleok / jest-coverage-ratchet

Uses jest coverage output to raise acceptable coverage threshold to current coverage

jest-coverage-ratchet

Raises jest's minimum coverage thresholds (per category) if current coverage is higher.

What does it do?

Lets say you have some jest coverage thresholds set in the package.json for your project at the following values:

{
  "branches": 30,
  "functions": 30,
  "lines": 30,
  "statements": 50,
}

then you get inspired one day and write lots of tests. Now your actual coverage summary might look like this:

{
  "branches": 50,
  "functions": 60,
  "lines": 77,
  "statements": 50,
}

Great 🌸‼ Except you'd really like your accomplishment to set the new standard for test coverage in this project. jest-coverage-ratchet just does that automatically by looking at your current coverage summary, comparing it to your specified coverage thresholds, and updating the minimum for any threshold that is higher in the summary.

So given the previous values, running this script will update your coverage thresholds specified in the jest key of package.json to the following values:

{
  "branches": 50,
  "functions": 60,
  "lines": 77,
  "statements": 50,
}

Installation

Just add as a dev dependency to your project like

npm install --save-dev jest-coverage-ratchet

or

yarn add --dev jest-coverage-ratchet

I recommend then using the binary jest-coverage-ratchet as part of a prepush hook.

Assumptions

I know what happens when you assume, but jest-coverage-ratchet makes the following assumptions about your project.

• jest has been run for project at least once with --coverage so that there is a valid file at the path ./coverage/coverage-summary.json (alternatively pass a path with --coverageSummaryPath of ./your/path/to/coverage-summary.json)
• jest configuration object is present in the package.json that specifies at least:
  • coverage thresholds (alternatively pass a path with --configPath of ./your/path/to/jest.config.json)
  • 'json-summary' in your jest config's reporters list like so:

  {
    // ...
    "jest": {
      "coverageReporters": [
        "json-summary"
      ],
      "coverageThreshold": {
        "global": {
          "branches": Number,
          "functions": Number,
          "lines": Number,
          "statements": Number,
        }
      }
    },
    // ...
  }

Should this tool support things like piping the coverage data in as an argument? Of course it should. If you want to build that and send a PR I will be all smiles 😀✨. If not then you probably see me do it eventually.

Questions?

Just submit an issue or a PR, I'm no elitist.

jest-coverage-ratchet's Issues

Command returns empty object as new coverage thresholds

I defined the following script in my package.json:

"ratchet": "./node_modules/.bin/jest-coverage-ratchet",
"test:ratchet": "npm run ratchet -- --coverageSummaryPath './coverage/coverage-final.json'"

(I had to redefine coverageSummaryPath because the coverage report's name has changed since... 5 years ago)

When running npm run test:ratchet, I get the following output:

new coverage thresholds:
{}

coverage thresholds ratcheted 🔧

Note that my coverage-final.json is faaaaar from being empty.
Does anyone know how to fix this?

Rounding coverage values down

How do you guys handle small (<1%) fluctuations of coverage values?
I propose to enable an option to round the threshold values down in order to avoid errors thrown on minor test coverage decrements

utils.js

const takeMaxValues = R.reduce(
  (result, [key, val]) =>
    R.merge(result, { [key]: R.max(result[key] || 0, Math.floor(val)) }),
  {}
)

allow different path for coverage path

an option to change the path for the coverage-summary.json would be cool.

Not working with categories

jest-coverage-ratchet doesn't raise jest's minimum coverage thresholds per category if current coverage is higher.

In my case, I have in my package.json :

"coverageThreshold": { "./src/shared/utils/Misc.js": { "lines": 80, "statements": 80, "functions": 80, "branches": 80 }

And in my coverage-summary, the coverage for this file is 100%,, then when I run jest-coverage-ratchet it doesn't raise the current threshold coverage for this file, it only raises the global.

allow different configuration file

we use jest.config.js for our jest config.

would be nice to use and modify this config as well

Is there a mechanism to check the previously ran thresholds

Currently i am hardcoding the threshold values

 "coverageThreshold": {
      "global": {
        "lines": 80.00,
        "statements": 80.00,
        "functions": 80.00,
        "branches": 80.00
      }
    },

Is there a way to check the previous build coverage threshold and make sure that the coverage did not go low in the current build

How does it work?

Hello!
I'm trying to run jest-coverage-ratchet but it doesn't want to modify my package.json file.
File coverage-summary.json is created.

Here my test project: https://github.com/Ant-VAV/jest_tests

Can you explain what I do wrong?

thresholds updated in package.json when --configPath is provided

Support for `jest.config.js`?

This works great, but I use jest.config.js instead of using the package.json and when running the ratchet, it appends the new thresholds into package.json.

I tried jest-coverage-ratchet --config-path ./jest.config.js with no success. Even logged console.log(configPath) here https://github.com/Koleok/jest-coverage-ratchet/blob/master/src/index.js#L19. It did show the path to jest.config.js but still bumped the package.json