Unable to produce a Jest code coverage report

Question

Unable to produce a Jest code coverage report

I am currently developing a Next.js project in Typescript and using the SWC compiler. For testing, I have integrated @swc/jest. Although all my tests are passing successfully, the coverage report appears empty. Below is an excerpt from my jest.config.js:

module.exports = {
  'roots': ['<rootDir>/../src'],
  'moduleDirectories': ['node_modules', 'src'],
  'setupFilesAfterEnv': ['<rootDir>/setup-tests.js'],
  'coverageDirectory': '<rootDir>/../coverage',
  'verbose': true,
  'collectCoverage': true,
  'transform': {
    '^.+\\.(t|j)sx?$': [
      '@swc/jest',
      {
        'jsc': {
          target: 'es2021',
        },
        'sourceMaps': true,
      },
    ],
  },
  'collectCoverageFrom': [
    '<rootDir>/../src/**.{ts,js,tsx,jsx}',
    '!**/node_modules/**',
  ],
}

Here is how my file structure looks:

.
├── coverage
├── jest
│   ├── jest.config.js
│   ├── setup-tests.js
├── src/
├── tsconfig.json

The generated output displays as follows:

----------|---------|----------|---------|---------|-------------------
File      | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s 
----------|---------|----------|---------|---------|-------------------
All files |       0 |        0 |       0 |       0 |                   
----------|---------|----------|---------|---------|-------------------

Test Suites: 11 passed, 11 total
Tests:       25 passed, 25 total
Snapshots:   0 total
Time:        1.307 s
Ran all test suites.

I have raised an issue on @swc/jest's repository but considering other possibilities, I would like to seek advice here as well.

typescript testing jestjs next.js swc-compiler

Answer 1

Answer №1

The configuration setting for 'collectCoverageFrom' in your jest setup appears to be incorrect. To properly include all directories and sub-directories, use a double asterisk **. You can also use a single * as a wildcard for directory or file names.

If you want to capture all files in all directories, regardless of sub-directories:

src/**/*

To only include js and ts files in all directories:

src/**/*.{js,ts}

To include all files within the src directory only:

src/*

It seems that your current configuration is matching directories that end with specific extensions such as js, ts, etc.

Answer 2

The configuration setting for 'collectCoverageFrom' in your jest setup appears to be incorrect. To properly include all directories and sub-directories, use a double asterisk **. You can also use a single * as a wildcard for directory or file names.

If you want to capture all files in all directories, regardless of sub-directories:

src/**/*

To only include js and ts files in all directories:

src/**/*.{js,ts}

To include all files within the src directory only:

src/*

It seems that your current configuration is matching directories that end with specific extensions such as js, ts, etc.

Unable to produce a Jest code coverage report

Answer №1

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