text: const fs = require('fs');
  const {join} = require('path');
  const {promisify} = require('util');
  const acorn = require('acorn');
  const acornWalk = require('acorn-walk');
  const dynamicImport = require('acorn-dynamic-import').default;
  const inject = require('acorn-dynamic-import/lib/walk').default;
  
  const walk = inject(acornWalk);
  const readFile = promisify(fs.readFile);
  
  (async function() {
    const source = await readFile(join('fixtures', 'base.mjs'));
    const program = acorn.Parser.extend(dynamicImport).parse(source, { sourceType: 'module', ranges: true });
  
    walk.simple(program, {
      'Import': function(node) {
        console.log('import', node);
      }
    });
  }());