Jest-metadata NPM

jest-metadata

🦸‍♂️ Superhero power for your Jest reporters! 🦸‍♀️

jest-metadata is a library that allows you to attach user-defined data to any jest-circus entity like describe blocks, function definitions, test runs, invocations, and more. Custom reporters can access your custom data to produce rich and insightful reports leveraging low-level details from jest-circus events and any additional data you want to use in your reports.

🌟 Features

Attach custom metadata to Jest entities such as describe blocks, function definitions, test runs, and invocations.
Access your metadata from your reporters to generate insightful reports.
Graceful degradation for default test environments (node, jsdom) and jest-jasmine2 test runner.
Custom test environment support via a decorator class.

📚 Guidelines

This library is primarily intended for the authors of custom Jest reporters. Direct usage of jest-metadata in test files is not recommended.

To use jest-metadata, you should:

Declare jest as a peer dependency (or direct one) in your package.
Provide your reporter as a class that inherits from jest-metadata/reporter.
Provide your test environment as a decorator class that can inherit from any WithMetadata(*) class.
Think about using a namespace for your metadata, so it doesn't clash with other metadata.

The best live example of how to use jest-metadata at the moment is jest-allure2-reporter.

🚀 Quick Start

To get your hands dirty, you can try out jest-metadata directly in your project.

Install jest-metadata using npm:

npm install jest-metadata --save-dev

In your Jest config, add the following:

+  "testEnvironment": "jest-metadata/environment-node",
+  "reporters": [
+    "default",
+    "./your-custom-reporter.js",
+  ],

If you need to use jest-metadata in a JSDOM environment or another custom test environment, please refer to the Integrating jest-metadata into test environment guide.

📖 Usage

In a Test File

Attach metadata to test entities using annotations:

import { metadata, $Set } from 'jest-metadata';

// Write your own DSL for attaching metadata to test entities
// Try to namespace your metadata to avoid collisions with other libraries
const $Description = (text) => $Set('mycompany.description', text);

$Description('This is a sample test suite.');
describe('Login flow', () => {

  $Description('This is a login test.');
  it('should login', () => {
    // ...
    metadata.push('mycompany.attachements', [
      { name: 'screenshot', type: 'image/png', filePath: '/path/to/screenshot.png' },
    ]);
    // ...
  });
});

In a Custom Reporter

Access metadata in a custom Jest reporter:

import { state } from 'jest-metadata';
import { JestMetadataReporter } from 'jest-metadata/reporter';

class CustomReporter extends JestMetadataReporter {
  async onTestCaseResult(test, testCaseResult) {
    await super.onTestCaseResult(test, testCaseResult);

    const metadata = state.getTestFileMetadata(test.path).lastTestEntry;

    const titles = [testCaseResult.title, ...testCaseResult.ancestorTitles.slice().reverse()];
    const descriptions = [metadata, ...metadata.ancestors()].map((m) => m.get('mycompany.description', '')).find(x => x);
    const attachments = [metadata, ...metadata.ancestors()].flatMap((m) => m.get('mycompany.attachements', []));

    const n = titles.length;
    for (let i = n - 1; i >= 0; i--) {
      console.log(`${titles[i]}: ${descriptions[i]}`);
    }
    // Output:
    // > Login flow: This is a sample test suite.
    // > should login: This is a login test.
  }
}

📄 Documentation

For more detailed documentation and examples, see the docs folder.

🌐 Contributing

We welcome contributions from the community! To get involved, please follow these steps:

Check the GitHub issues for open tasks or submit a new issue if you have a feature request or bug report.
Fork the repository and create a new branch for your changes.
Make your changes and submit a pull request.

For more information, see our Contribution Guidelines.