Karma Cucumber Reporter

Common errors

• Error: No reporters found: cucumber

  cause The 'cucumber' reporter string is missing from the `reporters` array in `karma.conf.js`, or the `karma-cucumber-reporter` plugin itself was not explicitly `require`d in the `plugins` array.
  fix Ensure `reporters: ['progress', 'cucumber']` and `plugins: [..., require('karma-cucumber-reporter')]` are correctly configured in `karma.conf.js`.

• Cucumber report file is empty or missing after test run

  cause The `out` option for `cucumberReporter` is not set, or tests do not match the required `prefix` or structural requirements for features and scenarios.
  fix Verify `cucumberReporter.out` is set to a valid file path (e.g., `./cucumber-report.json`) and that test `describe` blocks adhere to `describe('YOUR_PREFIX FEATURE_NAME', function() { describe('SCENARIO_NAME', function() { ... }); });` where `YOUR_PREFIX` matches the `cucumberReporter.prefix` option.

• Tests run, but do not appear in the generated Cucumber report, or the report is malformed.

  cause Test `describe` blocks do not follow the expected `PREFIX FEATURE` and `SCENARIO` nested structure, or the `prefix` option in `karma.conf.js` does not match the test `describe` block's prefix.
  fix Ensure your tests conform strictly to `describe('YourPrefix Your Feature Name', function() { describe('Your Scenario Name', function() { ... }); });` and that `cucumberReporter.prefix` in `karma.conf.js` exactly matches `YourPrefix`.

Warnings

• gotcha Tests must adhere to a specific `describe` block syntax for features and scenarios. Features require `describe('PREFIX FEATURE_NAME', function() { ... })` and scenarios require a nested `describe('SCENARIO_NAME', function() { ... })` block. Tests not matching this structure will not be correctly reported.
  Fix: Structure your test files using outer `describe('YOUR_PREFIX Your Feature Name', ...)` and inner `describe('Your Scenario Name', ...)` blocks for all tests intended for the Cucumber report.
• gotcha The `prefix` option in `cucumberReporter` configuration must exactly match the `PREFIX` string used in your test's top-level `describe` blocks (e.g., `describe('YOUR_PREFIX My Feature')`). Mismatched prefixes will cause tests to be excluded from the report.
  Fix: Ensure `cucumberReporter.prefix` in `karma.conf.js` is identical to the prefix used in your feature `describe` blocks in test files.
• gotcha Each feature `describe` block (e.g., `describe('PREFIX FEATURE_NAME', ...)`) must contain at least one nested scenario `describe` block (e.g., `describe('SCENARIO_NAME', ...)`). Empty feature blocks will not be correctly processed.
  Fix: Always include one or more `describe('Scenario Name', ...)` blocks within each `describe('Prefix Feature Name', ...)` block.

Install

• npm install karma-cucumber-reporter npm
• yarn add karma-cucumber-reporter yarn
• pnpm add karma-cucumber-reporter pnpm

Imports

• karma-cucumber-reporter plugin
  wrong:

  import { KarmaCucumberReporter } from 'karma-cucumber-reporter';

  correct:

  require('karma-cucumber-reporter')

  This package is a Karma plugin and is configured by directly requiring it in the `plugins` array of `karma.conf.js`. It does not export symbols for direct import or instantiation.
• reporters configuration

  reporters: ['progress', 'cucumber']

  The reporter is enabled by adding 'cucumber' to the `reporters` array in your `karma.conf.js`.
• cucumberReporter options

  cucumberReporter: { out: './report.json', prefix: 'MyApp' }

  Configuration options like `out` (output file path) and `prefix` (to filter tests) are set under the `cucumberReporter` property in `karma.conf.js`.

Quickstart

This quickstart demonstrates how to install and configure `karma-cucumber-reporter` in `karma.conf.js`. It includes an example test file structured with the required `PREFIX FEATURE` and `SCENARIO` `describe` blocks, showing how to produce a `cucumber-report.json` output file compatible with Cucumber reporting tools.

npm install -D karma karma-jasmine karma-chrome-launcher karma-cucumber-reporter

// karma.conf.js
module.exports = function(config) {
  config.set({
    frameworks: ['jasmine'],
    files: [
      'test/**/*.spec.js'
    ],
    reporters: ['progress', 'cucumber'],
    plugins: [
      'karma-jasmine',
      'karma-chrome-launcher',
      require('karma-cucumber-reporter')
    ],
    browsers: ['ChromeHeadless'],
    singleRun: true,
    autoWatch: false,
    cucumberReporter: {
      out: './cucumber-report.json', // Output file for the Cucumber JSON report
      prefix: 'FeaturePrefix'       // Prefix to identify features for reporting
    }
  });
};

// test/example.spec.js
describe('FeaturePrefix MyApplication Feature', function () {
  describe('Scenario: As a user, I can log in successfully', function () {
    it('Given I am on the login page', function () {
      expect(true).toBe(true); // Placeholder for actual test logic
    });

    it('When I enter valid credentials', function () {
      expect('username').toEqual('username');
      expect('password').toEqual('password');
    });

    it('Then I should be redirected to the dashboard', function () {
      expect(1 + 1).toBe(2);
    });
  });

  describe('Scenario: As an admin, I can manage users', function () {
    it('Given I am logged in as an admin', function () {
      expect(true).toBe(true);
    });
    it('When I navigate to the user management section', function () {
      expect(true).toBe(true);
    });
    it('Then I should see a list of users', function () {
      expect(false).not.toBe(true);
    });
  });
});