This is the "scripts" section of the package.json file that was initially generated using create-react-app:

"scripts": {
  "start": "concurrently \"react-scripts start\" \"node server.js\"",
  "build": "react-scripts build",
  "eject": "react-scripts eject",
  "test": "react-scripts test --env=jsdom --coverage --watchAll",
  "start:server": "node server"
},

I would like to configure Jest to have a coverage threshold like this:

"jest": {
  "coverageThreshold": {
    "global": {
      "branches": 100,
      "functions": 100,
      "lines": 100,
      "statements": 100
    }
  }
}

However, when I run yarn test it does not look like the "jest" portion is being executed. Is there something extra I need to add b/c this project was built with create-react-app?

Thanks!

This is the "scripts" section of the package.json file that was initially generated using create-react-app:

"scripts": {
  "start": "concurrently \"react-scripts start\" \"node server.js\"",
  "build": "react-scripts build",
  "eject": "react-scripts eject",
  "test": "react-scripts test --env=jsdom --coverage --watchAll",
  "start:server": "node server"
},

I would like to configure Jest to have a coverage threshold like this:

"jest": {
  "coverageThreshold": {
    "global": {
      "branches": 100,
      "functions": 100,
      "lines": 100,
      "statements": 100
    }
  }
}

However, when I run yarn test it does not look like the "jest" portion is being executed. Is there something extra I need to add b/c this project was built with create-react-app?

Thanks!

• javascript
• reactjs
• jestjs
• package.json
• create-react-app

5 Answers 5

package.json

1. Add a new npm script to coverage

"scripts": {
    "start": "react-scripts start",
    "build": "react-scripts build",
    "test": "react-scripts test",
    "coverage": "npm test -- --coverage",
    "eject": "react-scripts eject"
}

2. And add a jest config

"jest": {
    "coverageThreshold": {
      "global": {
        "statements": 100,
        "branches": 50,
        "functions": 100,
        "lines": 100
      }
    }
  },

3. npm run coverage

Now, react-app-rewired could be a new path to take.

You can config Jest in package.json in a jest section mentioned here: https://github.com/timarney/react-app-rewired#2-jest-configuration---testing

You can override certain coverage reporting metrics as indicated by create-react-app#coverage-reporting. Mind you, this has to be configured inside your package.json because that is where create-react-app looks for you overrides (aka, not inside .jestrc or jest.config.js files). But as @Andreas mentioned, if you want full control, eject or create your own config.

As a side notes, you may be able to pull out the jest configuration from create-react-app by using the --config flag with test script (from jest) and just copy that into your own config with your updates. May be easier than figuring out what create-react-app is doing.

The problem is that create-react-app uses its own settings here. The easiest thing would be to eject: npm run eject, to have the full controll over the settings.

Another way would be to copy over all the settings to your own settings and start the test with the additional parameter --config=<pathToYourSettings>

You can refer to this latest link: Configuring threshold limit

By adding this to your package.json:

"jest": {
    "coverageThreshold": {
      "global": {
        "branches": 75,
        "functions": 75,
        "lines": 75,
        "statements": 75
      }
    }
  }