string-template.js

const context = {
  title: 'hello',
  list: [1, 2, 3]
}

const template = '  \
  <header>${title}</header>  \
  <ul>${list.map(i => `<li>${i}</li>`).join("")}</ul> \
'

// note: make sure template and context are safe!
const templateFn = new Function(...Object.keys(context), `return \`${template.trim()}\``)

// "<header>hello</header>    <ul><li>1</li><li>2</li><li>3</li></ul>"
templateFn(...Object.values(context))