npm and yarn - see code coverage on entire project

How to show the details about which files are covered and how much code coverage they have?

Use these in jest-config.js

collectCoverage

1. https://jestjs.io/docs/configuration#collectcoverage-boolean

collectCoverageFrom

https://jestjs.io/docs/configuration#collectcoveragefrom-array

Configure Jest for code coverage in package.json or jest.config.js

In package.json

{
  "scripts": {
    "test": "jest --coverage"
  },
  "jest": {
    "collectCoverage": true,
    "coverageReporters": ["text", "lcov"],
    "collectCoverageFrom": [
      "src/**/*.{js,jsx,ts,tsx}",
      "!src/**/*.d.ts"
    ]
  }
}

The collectCoverageFrom option ensures that Jest collects coverage data from specified files, even if they don’t have explicit test files. In jest.config.js.

Using javascript

module.exports = {
  collectCoverage: true,
  coverageReporters: ["text", "lcov"],
  collectCoverageFrom: [
    "src/**/*.{js,jsx,ts,tsx}",
    "!src/**/*.d.ts"
  ],
};

Running tests

npm jest --coverage