Quick JS templating with string template literals

templatejs.js

const resolveExpression = exp => {
  const resolved = typeof exp === "function" ? exp() : exp;
  return Array.isArray(resolved)
    ? resolved.join("")
    : typeof resolved !== "undefined" ? resolved : "";
};

const html = (strings, ...exps) => {
  return strings.reduce((acc, str, i) => {
    return `${acc}${resolveExpression(exps[i - 1])}${str}`;
  }, "");
};

html`
    <foo>
    ${[1, 2, 3].map(i => {
      return html`<div>${i}</div>`;
    })}
    </foo>
`;

/**
* <foo>
*   <div>1</div>
*   <div>2</div>
*   <div>3</div>
* </foo>