The key thing to note here is that it is completely _lexical_ in scope - this only generates one tagged template even when called multiple times:

  function lexicalMagic() {
    const callHistory = [];
  
    function tag(strings, ...values) {
      callHistory.push(strings);
      // Return a freshly made object
      return {};
    }

    function evaluateLiteral() {
      return tag`Hello, ${"world"}!`;
    }
    return { evaluateLiteral, callHistory }
  }

We can create multiple "instances" of our closures, just as we expect and they do in fact produce distinct everything-else:

  > const first = lexicalMagic()
  > const second = lexicalMagic()
  > first.evaluateLiteral === second.evaluateLiteral
  false
  > first.callHistory === second.callHistory
  false

Using them doesn't behave any differently than the unclosured versions (as expected):

  > first.evaluateLiteral() === first.evaluateLiteral()
  false
  > first.callHistory[0] === first.callHistory[1]
  true
  > second.evaluateLiteral() === second.evaluateLiteral()
  false
  > second.callHistory[0] === second.callHistory[1]
  true

However, there is only one instance of the template literal, not two as we might expect. This is really helpful for some cases, but it definitely is surprising given the rest-of-JS:

  > first.callHistory[0] === second.callHistory[1]
  true