ifyoumakeit

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}`;

catb0t

# modified from Original source: https://github.com/python/mypy/issues/731#issuecomment-539905783
from typing import Union, Dict, List

JSONPrimitive = Union[str, int, bool, None]
JSONType = Union[JSONPrimitive, 'JSONList', 'JSONDict']

# work around mypy#731: no recursive structural types yet
class JSONList(List[JSONType]):
    pass