Stringify multiple JS Object Types

uneval.js

function uneval(o) {
  switch (typeof o) {
    case "undefined": return "(void 0)";
    case "boolean": return String(o);
    case "number": return String(o);
    case "string": return `"${o.replace(/\W/gi, function(_) { return `\\u${(0x10000 + _.charCodeAt(0)).toString(16).slice(1)}` })}"`;
    case "function": return `(${o.toString()})`;
    case "object":
      if (o == null) return "null";
      let ret, type = Object.prototype.toString.call(o).match(/\[object (.+)\]/);
      if (!type) throw TypeError(`unknown type: ${o}`);
      switch (type[1]) {
        case "Array":
          ret = [];
          for (let i = 0, l = o.length; i < l; ret.push(arguments.callee(o[i++])));
          return `[${ret.join(",")}]`;
        case "Object":
          ret = [];
          for (let i in o) {
            if (o.hasOwnProperty(i)) ret.push(`${arguments.callee(i)}:${arguments.callee(o[i])}`);
          };
          return `({${ret.join(",")}})`;
        case "Number": return `(new Number(${o}))`;
        case "String": return `(new String(${arguments.callee(o)}))`;
        case "Date": return `(new Date(${o.getTime()}))`;
        case "Error": return `(new Error('${o.message.replace(/\W/gi, function(_) { return `\\u${(0x10000 + _.charCodeAt(0)).toString(16).slice(1)}` })}'))`;
        default:
          if (o.toSource) return o.toSource();
          throw TypeError(`unknown type: ${o}`);
      }
  }
  return "";
}

/*

  Using eval() on the return value will return the same thing as the original input

  input                          | return value                        | eval(return value)
  -------------------------------|-------------------------------------|---------------------------------
  true                           | 'true'                              | true
  42                             | '42'                                | 42
  "Hello World"                  | '"Hello\u002c\u0020World\u0021"'    | 'Hello, World!'
  function a(b){return b}        | '(function a(b){return b})'         | function a(b){return b}
  ["one", 2, "three"]            | '["one",2,"three"]'                 | [ 'one', 2, 'three' ]
  {key: "value", key2: "value2"} | '({"key":"value","key2":"value2"})' | { key: 'value', key2: 'value2' }

*/