function render (template, options) {
  return template.replace(/\{\{\s?([\w.]+)\s?\}\}/g, (match, variable) => {
    return variable.split('.').reduce((previous, current) => {
      return previous[current]
    }, options) || ''
  })
}

describe('#render', () => {
  const template = '<h1>{{ the_title }}</h1><h2>{{ the_subtitle }}</h2>'
  
  const nested_template = `
    <li data-id="{{ id }}">
      <img src="{{ photos.primary.url }}" alt="{{ photos.primary.description }}">
      <p>
        <strong>{{ name.first }} {{ name.last }}</strong>
        <small>{{ role }}</small>
      </p>
    </li>
`
  
  const data = {
    the_title: 'hello, world!',
    the_subtitle: 'an experiment in javascript'
  }
  const expected = '<h1>hello, world!</h1><h2>an experiment in javascript</h2>'
  const empty_expected = '<h1></h1><h2></h2>'
  
  it('interpolates data into the template', () => {
    expect(render(template, data).indexOf(data.the_title)).toBe(4)
  })
  
  it('interpolates multiple strings into the template', () => {
    expect(render(template, data)).toBe(expected)
  })
  
  it('interpolates nothing if the property is not in the options hash', () => {
    expect(render(template, {})).toBe(empty_expected)
  })
  
  it('interpolates nested property names as well as flat data', () => {
    const myEmployee = {
      id: 'asdfsafdasdfasdfa',
      name: {
        first: 'Bob',
        last: 'Builder'
      },
      role: 'Lead Engineer',
      photos: {
        primary: {
          url: 'foobar.com/img.jpg',
          description: 'A photo of Bob the Builder'
        }
      }
    }
    
    expect(render(nested_template, myEmployee)).toContain('data-id="asdfsafdasdfasdfa"')
    expect(render(nested_template, myEmployee)).toContain('alt="A photo of Bob the Builder"')
    expect(render(nested_template, myEmployee)).toContain('src="foobar.com/img.jpg"')
    expect(render(nested_template, myEmployee)).toContain('<strong>Bob Builder</strong>')
    expect(render(nested_template, myEmployee)).toContain('<small>Lead Engineer</small>')
  })
})