Jest: Code Coverage doesn't fail with 0% cover.

[n8ores]

🐛 Bug Report

Running JEST with code coverage enabled does not fail if the code coverage is 0%

To Reproduce

Enable JEST with the following configuration file

"jest": {
"collectCoverage": true,
"coverageDirectory": "../coverage",
"testPathIgnorePatterns": [
"/node_modules/"
],
"verbose": true,
"coverageThreshold": {
"global": {
"branches": 50,
"functions": 50,
"lines": 50,
"statements": 50
}
}
},

Then call your JEST script.

Expected behavior

JEST should fail with exit code 1 as the coverage limits are set to 50% and the test returned 0%.

[thymikee]

Please provide a repro somebody can download and triage.

[n8ores]

Dear Michal,

The bug template says providing a repro is optional (not required).

This can be reproduced using ANY vanilla install of NodeJS with the
attacked package.json file provided.

Regards,

Nathan Parrott
MBA, BEng Mechatronics

www.nathanparrott.com
[phone]

On Thu, 13 Jun 2019 at 10:59, Michał Pierzchała [e-mail]
wrote:

Please provide a repro somebody can download and triage.

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[thymikee]

It's optional, that's why I'm not closing this issue :) (however I could do it, because you removed quite some important information, like which version of Jest you use, which Node, which OS). But it will make it easier for us to triage this.

For example, without a repro project, there's like 1% chances I'm gonna look at it. It's dramatically higher with a repro. Your choice! 🙂

[n8ores]

Fair enough:

Jest Version: 24.8.0 (latest)
OS: Confirmed to fail on windows, Mac & Linux
Node :10.15.3

[stonefruit]

Hello. I am also having an issue. Here is a repro: https://github.com/stonefruit/repro-jest-coverage.

npx create-react-app repro-jest-coverage

cd repro-jest-coverage

npm test -- --coverage

The above is used to create the repro. The coverage shown 'All files' with all 0s as described by @n8ores.

npm test -- --coverage

 PASS  src/App.test.js
  ✓ renders without crashing (22ms)

----------|----------|----------|----------|----------|-------------------|
File      |  % Stmts | % Branch |  % Funcs |  % Lines | Uncovered Line #s |
----------|----------|----------|----------|----------|-------------------|
All files |        0 |        0 |        0 |        0 |                   |
----------|----------|----------|----------|----------|-------------------|
Test Suites: 1 passed, 1 total
Tests:       1 passed, 1 total
Snapshots:   0 total
Time:        2.078s
Ran all test suites.

While the --watchAll flag shows the files.

npm test -- --coverage --watchAll

 PASS  src/App.test.js
  ✓ renders without crashing (23ms)

------------------|----------|----------|----------|----------|-------------------|
File              |  % Stmts | % Branch |  % Funcs |  % Lines | Uncovered Line #s |
------------------|----------|----------|----------|----------|-------------------|
All files         |     2.44 |        0 |     6.25 |     2.44 |                   |
 App.js           |      100 |      100 |      100 |      100 |                   |
 index.js         |        0 |      100 |      100 |        0 |              7,12 |
 serviceWorker.js |        0 |        0 |        0 |        0 |... 23,130,131,132 |
------------------|----------|----------|----------|----------|-------------------|
Test Suites: 1 passed, 1 total
Tests:       1 passed, 1 total
Snapshots:   0 total
Time:        2.562s
Ran all test suites.

Since there is a test for App.test.js, I think we should be expecting something that looks like (not accurate):

------------------|----------|----------|----------|----------|-------------------|
File              |  % Stmts | % Branch |  % Funcs |  % Lines | Uncovered Line #s |
------------------|----------|----------|----------|----------|-------------------|
All files         |     2.44 |        0 |     6.25 |     2.44 |                   |
 App.js           |      100 |      100 |      100 |      100 |                   |
------------------|----------|----------|----------|----------|-------------------|

[kezarmader]

Any update on this issue?

[diazgilberto]

I'm having the same issue here.

• "jest": "^24.9.0"
• MBP 10.14.6
• Nodejs 12.13.0

jest settings inside package.json

  "scripts": {
    "test": "jest",
    "test:watch": "npm run test -- --watch",
    "test:coverage": "npm run test -- --coverage --coverageDirectory=.jest",
    "generate:docs": "jsdoc -c ./jsdoc.conf.json"
  }

...

  "jest": {
    "rootDir": "./",
    "verbose": true,
    "collectCoverageFrom": [
      "**/*.{js}",
      "!**/node_modules/**",
      "!**/tools/**",
      "!**/build/**",
      "!**/docs/**"
    ],
    "coverageThreshold": {
      "global": {
        "statements": 100,
        "branches": 100,
        "functions": 100,
        "lines": 100
      }
    }
  },

outcome

----------|----------|----------|----------|----------|-------------------|
File      |  % Stmts | % Branch |  % Funcs |  % Lines | Uncovered Line #s |
----------|----------|----------|----------|----------|-------------------|
All files |        0 |        0 |        0 |        0 |                   |
----------|----------|----------|----------|----------|-------------------|
Test Suites: 13 passed, 13 total
Tests:       66 passed, 66 total
Snapshots:   0 total
Time:        1.525s
Ran all test suites.

[diazgilberto]

I'm having the same issue here.

• "jest": "^24.9.0"
• MBP 10.14.6
• Nodejs 12.13.0

jest settings inside package.json

  "scripts": {
    "test": "jest",
    "test:watch": "npm run test -- --watch",
    "test:coverage": "npm run test -- --coverage --coverageDirectory=.jest",
    "generate:docs": "jsdoc -c ./jsdoc.conf.json"
  }

...

  "jest": {
    "rootDir": "./",
    "verbose": true,
    "collectCoverageFrom": [
      "**/*.{js}",
      "!**/node_modules/**",
      "!**/tools/**",
      "!**/build/**",
      "!**/docs/**"
    ],
    "coverageThreshold": {
      "global": {
        "statements": 100,
        "branches": 100,
        "functions": 100,
        "lines": 100
      }
    }
  },

outcome

----------|----------|----------|----------|----------|-------------------|
File      |  % Stmts | % Branch |  % Funcs |  % Lines | Uncovered Line #s |
----------|----------|----------|----------|----------|-------------------|
All files |        0 |        0 |        0 |        0 |                   |
----------|----------|----------|----------|----------|-------------------|
Test Suites: 13 passed, 13 total
Tests:       66 passed, 66 total
Snapshots:   0 total
Time:        1.525s
Ran all test suites.

I found the solution to the problem. In the "jest": ... part within package.json substitute the ./ root for <rootDir>.

  "jest": {
    "collectCoverageFrom": [

      "<rootDir>/test/**/*.js"

    ],
    "coveragePathIgnorePatterns": [
      "<rootDir>/node_modules/",
      "<rootDir>/tools/",
      "<rootDir>/build/",
      "<rootDir>/docs/"
    ]

[cansin]

@diazgilberto that did not work for me unfortunately.

[diazgilberto]

@diazgilberto that did not work for me unfortunately.

@cansin do you have your jest settings inside package.json?

[cansin]

Yes, I realized doing jest --coverage works, versus having collectCoverage: true inside jest.config.js does not.

[diazgilberto]

Yes, I realized doing jest --coverage works, versus having collectCoverage: true inside jest.config.js does not.

Interesting is that even though I have all jest configuration inside package.json I still need an empty jest.config.js file in project root. If I remove that file, code coverage reports 0 again.

Now I'm having a different issue where coverage is reporting wrong % stating that I'm missing to test a particular line of code.

This is the code that is reporting wrong coverage

if (value.length === 0 && defaultValue !== undefined) {
  console.log('VALUE: ', value, ' DEFAULT: ', defaultValue)
  return defaultValue
}

console.log() inside the function that clearly shows that the function is getting tested.

  console.log lib/validation/validateString.js:38
    VALUE:    DEFAULT:  test

-------------------|----------|----------|----------|----------|-------------------|
File               |  % Stmts | % Branch |  % Funcs |  % Lines | Uncovered Line #s |
-------------------|----------|----------|----------|----------|-------------------|
All files          |      100 |    91.67 |      100 |      100 |                   |
 validateString.js |      100 |    91.67 |      100 |      100 |                37 |
-------------------|----------|----------|----------|----------|-------------------|
Test Suites: 1 passed, 1 total
Tests:       7 passed, 7 total
Snapshots:   0 total
Time:        0.791s, estimated 2s
Ran all test suites matching /validateString/i.

[npeham]

Watch out for this warning:

ts-jest[versions] (WARN) Version 24.9.0 of jest installed has not been tested with ts-jest. If you're experiencing issues, consider using a supported version (>=22.0.0 <24.0.0). Please do not report issues in ts-jest if you are using unsupported versions.

Downgrading jest fixed the bug for me without changing the command. I also did not add the --watchAll flag.

[ssrinathsri]

Hi, We can follow the below jest configuration...

"jest": {
"moduleFileExtensions": [
"js",
"json",
"ts"
],
"rootDir": ".",
"testRegex": ".spec.ts$",
"transform": {
"^.+\.(t|j)s$": "ts-jest"
},
"coverageDirectory": "./coverage",
"testEnvironment": "node",
"collectCoverage": true,
"verbose": true
}