test/parallel/test-runner-coverage.js

'use strict';
const common = require('../common');
const assert = require('node:assert');
const { spawnSync } = require('node:child_process');
const { readdirSync } = require('node:fs');
const { test } = require('node:test');
const fixtures = require('../common/fixtures');
const tmpdir = require('../common/tmpdir');

tmpdir.refresh();

function findCoverageFileForPid(pid) {
  const pattern = `^coverage\\-${pid}\\-(\\d{13})\\-(\\d+)\\.json$`;
  const regex = new RegExp(pattern);

  return readdirSync(tmpdir.path).find((file) => {
    return regex.test(file);
  });
}

function getCoverageFixtureReport() {
  const report = [
    '# start of coverage report',
    '# file | line % | branch % | funcs % | uncovered lines',
    '# test/fixtures/test-runner/coverage.js | 78.65 | 38.46 | 60.00 | 12, ' +
    '13, 16, 17, 18, 19, 20, 21, 22, 27, 39, 43, 44, 61, 62, 66, 67, 71, 72',
    '# test/fixtures/test-runner/invalid-tap.js | 100.00 | 100.00 | 100.00 | ',
    '# test/fixtures/v8-coverage/throw.js | 71.43 | 50.00 | 100.00 | 5, 6',
    '# all files | 78.35 | 43.75 | 60.00 |',
    '# end of coverage report',
  ].join('\n');

  if (common.isWindows) {
    return report.replaceAll('/', '\\');
  }

  return report;
}

test('--experimental-test-coverage and --test cannot be combined', () => {
  // TODO(cjihrig): This test can be removed once multi-process code coverage
  // is supported.
  const args = ['--test', '--experimental-test-coverage'];
  const result = spawnSync(process.execPath, args);

  // 9 is the documented exit code for an invalid CLI argument.
  assert.strictEqual(result.status, 9);
  assert.match(
    result.stderr.toString(),
    /--experimental-test-coverage cannot be used with --test/
  );
});

test('handles the inspector not being available', (t) => {
  if (process.features.inspector) {
    return;
  }

  const fixture = fixtures.path('test-runner', 'coverage.js');
  const args = ['--experimental-test-coverage', fixture];
  const result = spawnSync(process.execPath, args);

  assert(!result.stdout.toString().includes('# start of coverage report'));
  assert(result.stderr.toString().includes('coverage could not be collected'));
  assert.strictEqual(result.status, 0);
  assert(!findCoverageFileForPid(result.pid));
});

test('coverage is reported and dumped to NODE_V8_COVERAGE if present', (t) => {
  if (!process.features.inspector) {
    return;
  }

  const fixture = fixtures.path('test-runner', 'coverage.js');
  const args = ['--experimental-test-coverage', fixture];
  const options = { env: { ...process.env, NODE_V8_COVERAGE: tmpdir.path } };
  const result = spawnSync(process.execPath, args, options);
  const report = getCoverageFixtureReport();

  assert(result.stdout.toString().includes(report));
  assert.strictEqual(result.stderr.toString(), '');
  assert.strictEqual(result.status, 0);
  assert(findCoverageFileForPid(result.pid));
});

test('coverage is reported without NODE_V8_COVERAGE present', (t) => {
  if (!process.features.inspector) {
    return;
  }

  const fixture = fixtures.path('test-runner', 'coverage.js');
  const args = ['--experimental-test-coverage', fixture];
  const result = spawnSync(process.execPath, args);
  const report = getCoverageFixtureReport();

  assert(result.stdout.toString().includes(report));
  assert.strictEqual(result.stderr.toString(), '');
  assert.strictEqual(result.status, 0);
  assert(!findCoverageFileForPid(result.pid));
});