Ensure incremental coverage gains are not lost, and positively reinforce good testing habits. Automatically bump up global Jest thresholds whenever coverage goes above them.

• Node.js 12+
• Conventional jest.config.js (package.json config unsupported)
• json-summary coverage report (see usage)

npm install --save-dev jest-it-up

jest-it-up exposes a standalone CLI tool (see options), but you most likelly want to use it in a post-test script.

Within package.json:

{
  "scripts": {
    "test": "jest --coverage", // or set `collectCoverage` to `true` in Jest config
    "posttest": "jest-it-up" // must run from the same directory as `jest.config.js`
  }
}

within jest.config.js:

module.exports = {
  coverageReporters: [
    'json-summary' // plus any other reporters, e.g. "lcov", "text", "text-summary"
  ],
  coverageThreshold: {
    global: {
      branches: 0, // or your current numbers
      functions: 0,
      lines: 0,
      statements: 0
    }
  }
}

Once tests finish running, jest-it-up will update configured thresholds to match higher coverage numbers, if any.

$ jest-it-up --help
Usage: jest-it-up [options]

Options:
  -m, --margin <margin>  minimum threshold increase (default: 0)
  -i, --interactive      ask for confirmation before applying changes
  -s, --silent           do not output messages
  -d, --dry-run          process but do not change files
  -v, --version          output the version number
  -h, --help             display help for command