你还在瞒着我偷偷使用强制相等

"1" == 1 // true
1 == "1" // true
true == 1 // true
1 == true // true
[1] == 1 // true
1 == [1] // true

function doubleEqual(a, b) {
  if (typeof a === typeof b) return a === b;
  if (wantsCoercion(a) && isCoercable(b)) {
    b = b.valueOf();
  } else if (wantsCoercion(b) && isCoercable(a)) {
    const temp = a.valueOf();
    a = b;
    b = temp;
  }
  if (a === b) return true;
  switch (typeof a) {
    case "string":
      if (b === true) return a === "1" || a === 1;
      if (b === false) return a === "0" || a === 0 || a == "";
      if (a === "" && b === 0) return true;
      return a === String(b);
    case "boolean":
      if (a === true) return b === 1 || String(b) === "1";
      else return b === false || String(b) === "0" || String(b) === "";
    case "number":
      if (a === 0 && b === false) return true;
      if (a === 1 && b === true) return true;
      return a === Number(String(b));
    case "undefined":
      return b === undefined || b === null;
    case "object":
      if (a === null) return b === null || b === undefined;
    default:
      return false;
  }
}

function wantsCoercion(value) {
  const type = typeof value;
  return type === "string" || type === "number" || type === "boolean";
}

function isCoercable(value) {
  return value !== null && typeof value == "object";
}