3

In Jest, is there a way from the command line to generate an HTML coverage report if it is not defined in the jest.config.js files?

I only want to generate the HTML report some of the time rather than every time I run Jest. The only way I've been able to generate the HTML report was by changing the config manually.

Ray Pierce
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3 Answers3

3

By default the collectCoverage option for jest is set to false. The easiest way to get an HTML coverage report is to configure jest in either package.json or jest.config.js. You will also need to set the coverageDirectory in the config as well.

There are several different configuration options for coverage reporting. See here for all config settings: https://jestjs.io/docs/en/configuration.html#collectcoverage-boolean

Here is an example of how to configure jest in package.json with a few options. 

{
  "name": "appname",
  "version": "1.0.0",
  "description": "description",
  "main": "index.js",
  "scripts": {
    "test": "jest",
    "postinstall": "jspm install"
  },
  "jest": {
    "scriptPreprocessor": "./preprocessor.js",
    "testPathIgnorePatterns": [
      "/node_modules/",
    ],
    "unmockedModulePathPatterns": [
      "./node_modules/react"
    ],
    "collectCoverage": true,
    "coverageDirectory": "path/to/coverage/reports",
  },
  "author": "author",
  "license": "ISC",
  "dependencies": {
    "del": "^1.1.1",
    "gulp": "^3.8.11",
    "gulp-filter": "^2.0.2",
    "gulp-load-plugins": "^0.10.0",
    "gulp-react": "^3.0.1",
    "gulp-shell": "^0.4.1",
    "harmonize": "^1.4.1",
    "jest-cli": "^0.4.1",
    "jspm": "^0.15.5",
    "react": "^0.13.2",
    "react-tools": "^0.13.2",
    "run-sequence": "^1.1.0"
  },
  "devDependencies": {
    "browser-sync": "^2.7.1",
    "gulp": "^3.8.11"
  },
  "jspm": {
    "directories": {},
    "dependencies": {
      "react": "npm:react@^0.13.2"
    },
    "devDependencies": {
      "babel": "npm:babel-core@^5.1.13",
      "babel-runtime": "npm:babel-runtime@^5.1.13",
      "core-js": "npm:core-js@^0.9.4"
    }
  }
}

Now when you run your test with jest --coverage the HTML reports will be generated in the specified directory.

enail131
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2

Have you tried to pass in a JSON config via the command line?

npx jest ./src/**/*.js --coverage --config='{ "coverageReporters": ["html"] }'

Sharkparty
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0

Here is a portion from my test scripts in package.json that may help you generate coverage reports:

"test": "react-scripts test --env=jsdom",
"test:coverage": "react-scripts test --coverage"

My setup uses jest@23.6.0 with enzyme@3.8.0 and jest-enzyme@7.0.1

Butifarra
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