Your test suite must contain at least one test

Question

I have updated some of the dependencies today in my project, but it went through really smoothly. Now, when I'm about to push it, I started my tests. And boom. All of them throw:

Your test suite must contain at least one test.

My packages:

"jest": "23.1.0",
"jest-enzyme": "^6.0.1",
"jest-webpack-alias": "^3.3.3",
"jsdom": "^11.2.0",
"jsdom-global": "^3.0.2",
"enzyme": "3.3.0",
"enzyme-adapter-react-16": "^1.1.0",
"enzyme-to-json": "3.3.4",

And that is how my sample test file looks like:

/shared/components/App/MyRoute/__tests__/MyRoute.test.js

/* eslint-disable import/no-extraneous-dependencies */
import React from 'react';
import { shallow } from 'enzyme';
import { ContactsRoute } from '../Route';

describe('<ContactsRoute />', () => {
  test('renders', () => {
    const wrapper = shallow(<ContactsRoute t={key => key} />);
    expect(wrapper).toMatchSnapshot();
  });
});

I have no idea why they stopped running so suddenly?

Edit - adding my jest config

  "jest": {
"collectCoverageFrom": [
  "shared/**/*.{js,jsx}"
],
"globals": {
  "JWT_SECRET": "local",
  "IS_TEST": "true"
},
"snapshotSerializers": [
  "<rootDir>/node_modules/enzyme-to-json/serializer"
],
"testPathIgnorePatterns": [
  "<rootDir>/(build|internal|node_modules|flow-typed|public|shared/services)/"
],
"moduleNameMapper": {
  "\\.(jpg|jpeg|png|gif|eot|otf|webp|svg|ttf|woff|woff2|mp4|webm|wav|mp3|m4a|aac|oga)$": "<rootDir>/_test_config_/mocks/fileMock.js"
},
"testURL": "http://localhost:3005",
"transform": {
  ".": "<rootDir>/_test_config_/preprocessors/webpackAlias.js",
  "^.+\\.css$": "<rootDir>/_test_config_/preprocessors/cssTransform.js",
  "^(?!.*\\.(js|jsx|css|json)$)": "<rootDir>/_test_config_/preprocessors/fileTransform.js"
},
"setupFiles": [
  "<rootDir>/_test_config_/preprocessors/polyfills.js"
],
"setupTestFrameworkScriptFile": "./node_modules/jest-enzyme/lib/index.js"
},

Answer 1

make sure describe / it/ expect variables are not been imported

In my case, the IDE( VSCode ) automatically import the variable describe from another library.

Answer 2

Make sure that you have at least one describe / it / expect

In my case, i wrote just a describe / expect test and got this error message

Answer 3

If all the other responses fail, if you have any files named test.js, Jest will expect that file to contain a test.

I was using a file named test.js to manually test some stuff, and Jest was throwing this error. I re-named the file to something else (eg: 123.js) and I stopped getting this error message.

Answer 4

May be you forgot it() block:

maybe you have a mistake and in somewhere code is like this:

describe('my test', () => {
    expect(...)...;
});

replace it with:

describe('my test', () => {
    it('some text', () => {
        expect(...)...;
    })
});

Answer 5

Make sure that your describe function is not async

// Wrong
describe('setPackages', async () => {
 // ...
});

// Correct
describe('setPackages', () => {
 // ...
});

Answer 6

So, I found the answer.

The Note in here says that if we are using babel-jest alongside with our own preprocessors, the babel-jest has to be explicitly defined in the transform option.

It is important to add "^.+\\.jsx?$": "babel-jest" as the first option in the transform config.

Answer 7

Another option is to call Jest with the --passWithNoTests argument, as documented here. The flag is useful when you don't know how many tests a script will run, such as with git commit hooks.

Answer 8

another issue which raises this Error is when you have put some none-test files into your __test__ directory.

All files in your __test__ directory must include some tests to run.

Answer 9

Might happen when you have a test file but the contents are not saved? Try saving the file before running the tests.