Jest No Tests found

Question

running docker mhart/alpine-node:8 on macOS with

nodejs (6.10.3-r0) (18/18) yarn 0.24.6 jest 20.0.4

I have a __tests__/index.test.js file however, when running the code

node_modules/.bin/jest --watchAll I get the below output

No tests found
In /usr/src/app
5 files checked.
testMatch: /__tests__/ /*.js?(x),**/?(*.)(spec|test).js?(x) - 1 match
testPathIgnorePatterns: /node_modules/,/src, src - 0 matches
Pattern: "" - 0 matches

I've re-installed the package numbers times but to no avail.

Answer 1

Your output says that testMatch had 1 match , which may be your __tests__/index.test.js file. It seems that your testPathIgnorePatterns is causing that test suite to be ignored. No tests found In /usr/src/app says that Jest is looking for tests in /usr/src/app , and testPathIgnorePatterns: /node_modules/,/src,src says that Jest is ignoring files in /src directories.

Either point Jest to look at the location of your __tests__/index.test.js file if it is outside the /src directory, or stop testPathIgnorePatterns from ignoring the /src directory.

Answer 2

If you have file structure such as the following

myFolder
│   myFile1.js
│   myFile2.js
│   ...
│   
└───__tests__
        myFile1.spec.js
        myFile2.spec.js
        ...

then you need to have in jest.config.js the following pattern for testMatch property:

testMatch: ['**/__tests__/*.js?(x)'],

The simple example of jest.config.js :

const jestConfig = {
  verbose: true,
  testURL: "http://localhost/",
  'transform': {
    '^.+\\.jsx?$': 'babel-jest',
  },
  testMatch: ['**/__tests__/*.js?(x)'],
}

module.exports = jestConfig

Answer 3

如果你想运行测试文件夹中的所有测试，你可以简单地执行以下jest __tests__ --watch

Answer 4

You can try running jest without any parameters. A key thing to note is the test file names have to follow the convention *.test.js or *.spec.js .

Answer 5

In package.json there is a pattern that is used to find test file. In this pattern, you can change it according to your file location or make it the global pattern.

I wrote a test, not in the specific folder and follow a naming convention *.test.js and change testMatch

"testMatch": [
      "<rootDir>/src/**/*.(test).{js,jsx,ts,tsx}",
      "<rootDir>/src/**/?(*.)(spec|test).{js,jsx,ts,tsx}"
    ],

Answer 6

Moving the __tests__ filter into src fixed the issue for me. Now its able to run the tests.

Answer 7

I had this error while attempting to run tests in a submodule of a project. Fixed the issue by testing the submodule in isolation, in a separate folder tree from the main project.

Answer 8

If you're using Typescript, I started getting the same No tests found error after I updated Typescript to 3.8.3 from 3.3. Updating jest and ts-jest from version 23.* to 25.* fixed it for me.