npm test -- --coverage never exits - node.js

Question

I am using create-react-app to create a react application. When I executes npm test -- --coverage the test never exists. npm test actually runs react-scripts test. Any Idea?

Answer 1

-- --coverage part won't work, and should use one of the commands below to set CI to true.
By default npm test runs the watcher with interactive CLI. However, you can force it to run tests once and finish the process by setting an environment variable called CI.
source: React docs
Windows (cmd.exe)
set CI=true && npm test
set CI=true && npm run build
Windows (Powershell)
($env:CI = "true") -and (npm test)
($env:CI = "true") -and (npm run build)
Linux, macOS (Bash)
CI=true npm test
CI=true npm run build
NOT included in the docs
For Docker (node and react):
docker run -e CI=true [myImage] npm run test

Answer 2

Coverage won't work with Jest in watch mode.
Because "react-scripts test --env=jsdom" works in watch mode by default, the watch mode has to be switched off while generating the coverage output.
The following excerpt from the package.json contains a line "coverage" for illustration, how code coverage can be achieved within an app which was bootet by create-react-app.
It's just the modified "test" script, where the options --watchAll=false and --coverage are added in combination:
"scripts": {
"start": "react-scripts start",
"build": "react-scripts build",
"test": "react-scripts test --env=jsdom",
"coverage": "react-scripts test --env=jsdom --watchAll=false --coverage",
"eject": "react-scripts eject"
}
Please note that it is obsolete to use standalone double-dash -- .

Answer 3

Most of the time this issue can be occur because of following reasons.
Not mentioning the required npm-script arguments in the
package.json file. If you use create-react-app to create your
react application, then it will not accept any command line
arguments. To resolve this problem, add following line under the
script tag in your package.json.
"test": "react-scripts test --coverage --watchAll", //mark --watchAll=false if you want.
Not mentioning the required jest configuration arguments in
the package.json or jest.config.js files. You should mention the files
which needed to include in your test coverage under the jest
configurations. Add following configurations in your
package.json.
package.json
"jest": {
"collectCoverageFrom": [
"src/**/*.js",
"!src/index.js", // files you need to avoid in test coverage
"!src/hooks/*.js",
"!src/context/*.js"
],
"coverageThreshold": {
"global": {
"branches": 90,
"functions": 90,
"lines": 90,
"statements": 90
}
},
"coverageReporters": [
"html",
"text"
]
},

Answer 4

Specifying a directory worked in my case
"test:cover": "react-scripts test --coverage src"

Answer 5

I tried all the solutions above, and for me it was still hanging with the message: Ran all test suites..
But this little hack helped:
"test:ci": "cross-env CI=true react-scripts test --forceExit --detectOpenHandles",
Explanation: The problem was coming from Jest not being able to close all processes. The above is a quick workaround. Ideally you should track the process that's stopping Jest from exiting.

Answer 6

In my case just added a new script "test:coverage": "react-scripts test --coverage"
"scripts": {
"start": "react-scripts start",
"build": "react-scripts build",
"test": "react-scripts test",
"test:coverage": "react-scripts test --coverage",
"eject": "react-scripts eject"
},