child_process.exec を使ってみた

元ネタは現代の JavaScript チュートリアル

sync_iterator.js

'use strict';

let range = {
  from: 1,
  to: 5,

  [Symbol.iterator]() {
    return {
      current: this.from,
      last: this.to,
      next() {
        if (this.current <= this.last)
          return { done: false, value: this.current++ };
        else
          return { done: true }
      }
    }
  }
}

for (const value of range) console.log(value);

test.js

'use strict';

const assert = require('assert');
const child_process = require('child_process');

describe('Async iterator', () => {
  it('should output sequence', done => {
    child_process.exec('node ./async_iterator.js', (error, stdout) => {
      assert.equal(stdout, '1\n2\n3\n4\n5\n');
      done();
    });
  });
});

参考にしたページ

Child Process | Node.js v12.9.1 Documentation