Package Exports

mutation-testing-metrics
mutation-testing-metrics/dist/src/index.js

This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (mutation-testing-metrics) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.

Readme

Mutation testing metrics

Utility function to calculate mutation testing metrics..

See mutant states and metrics on the Stryker website for more details about mutation testing metrics.

Usage example

See the below example (uses TypeScript):

import { MetricsResult, calculateMutationTestMetrics } from 'mutation-testing-metrics';
import { MutationTestResult } from 'mutation-testing-report-schema';

const mutationTestReport: MutationTestResult = {
  /*... Get a holds of mutation test results somehow */
};

const result: MetricsResult = calculateMutationTestMetrics(mutationTestReport);

console.log('Mutation score', result.metrics.mutationScore);

API Reference

`calculateMutationTestMetrics` [`(MutationTestResult) => MutationTestMetricsResult`]

Calculates the full mutation test metrics from both the files-under-test as well as (optionally) the test files.

The input is a mutation test result valid according to the [https://github.com/stryker-mutator/mutation-testing-elements/tree/master/packages/report-schema#readme]

Returns A MutationTestMetricsResult that contains both the systemUnderTestMetrics as well as the testMetrics

`calculateMetrics` [`(MutationTestResult) => MetricsResult`]

Calculates the files-under-test metrics inside of a mutation testing report.

The input is a mutation test result valid according to the [https://github.com/stryker-mutator/mutation-testing-elements/tree/master/packages/report-schema#readme]

`aggregateResultsByModule` [`(Record<string, MutationTestResult>) => MutationTestResult`]

Aggregates multiple reports together into a single report, grouped by module.

Input: resultsByModule The MutationTestResult objects by module name.

Types

Types are included and documented with TypeScript.

Use case: merging multiple JSON reports

You can use this script to merge multiple JSON reports together.

const { aggregateResultsByModule } = require('mutation-testing-metrics');
const fs = require('fs');

const packagesRoot = './packages';
const reportsPerModule = fs
  .readdirSync(packagesRoot)
  .map((pkg) => [pkg, `${packagesRoot}/${pkg}/reports/mutation/mutation.json`])
  .filter(([, report]) => fs.existsSync(report))
  .map(([pkg, report]) => [pkg, require(report)])
  .reduce((acc, [pkg, report]) => {
    acc[pkg] = report;
    return acc;
  }, {});

const monoReport = aggregateResultsByModule(reportsPerModule);
fs.writeFileSync('./mono-report.html', reportTemplate(monoReport), 'utf-8');

function reportTemplate(report) {
  const scriptContent = fs.readFileSync(require.resolve('mutation-testing-elements/dist/mutation-test-elements.js'), 'utf-8');

  return `<!DOCTYPE html>
  <html>
  <head>
    <meta charset="utf-8">
    <script>
      ${scriptContent}
    </script>
  </head>
  <body>
    <mutation-test-report-app>
      Your browser doesn't support <a href="https://caniuse.com/#search=custom%20elements">custom elements</a>.
      Please use a latest version of an evergreen browser (Firefox, Chrome, Safari, Opera, Edge, etc).
    </mutation-test-report-app>
    <script>
      const app = document.querySelector('mutation-test-report-app');
      app.report = ${escapeHtmlTags(JSON.stringify(report))};
      function updateTheme() {
        document.body.style.backgroundColor = app.theme === 'dark' ? '#222' : '#fff';
      }
      app.addEventListener('theme-changed', updateTheme);
      updateTheme();
    </script>
  </body>
  </html>`;
}
function escapeHtmlTags(json) {
  return json.replace(/</g, '<" + "');
}