Function asynctest

test/parallel/test-fs-realpath.js:70–84

(testBlock, args, callback, assertBlock)

fs.mkdirSync(path.join(targetsAbsDir, 'nested-index', 'two'));

function asynctest(testBlock, args, callback, assertBlock) {
  async_expected++;
  testBlock.apply(testBlock, args.concat(function(err) {
    let ignoreError = false;
    if (assertBlock) {
      try {
        ignoreError = assertBlock.apply(assertBlock, arguments);
      } catch (e) {
        err = e;
      }
    }
    async_completed++;
    callback(ignoreError ? null : err);
  }));
}

// sub-tests:
function test_simple_error_callback(realpath, realpathSync, cb) {