Function setupCoverage

lib/internal/test_runner/coverage.js:598–626

(options)

}

function setupCoverage(options) {
  let originalCoverageDirectory = process.env.NODE_V8_COVERAGE;

  // If NODE_V8_COVERAGE was already specified, convert it to an absolute path
  // and store it for later. The test runner will use a temporary directory
  // so that no preexisting coverage files interfere with the results of the
  // coverage report. Then, once the coverage is computed, move the coverage
  // files back to the original NODE_V8_COVERAGE directory.
  originalCoverageDirectory &&= resolve(options.cwd, originalCoverageDirectory);

  const coverageDirectory = mkdtempSync(join(tmpdir(), 'node-coverage-'));
  const enabled = setupCoverageHooks(coverageDirectory);

  if (!enabled) {
    return null;
  }

  internalBinding('profiler').startCoverage();

  // Ensure that NODE_V8_COVERAGE is set so that coverage can propagate to
  // child processes.
  process.env.NODE_V8_COVERAGE = coverageDirectory;

  return new TestCoverage(
    coverageDirectory,
    originalCoverageDirectory,
    options,
  );
}

function mapRangeToLines(range, lines) {
  const { startOffset, endOffset, count } = range;