Idiomatically handling pre-conditions with ES6 Promises

I am new to ES6 Promises and have been doing research. I have some code executing in NodeJS that does some async work, but I have a few pre-conditions that must be checked first. I'm seeking the idiomatic best-practice for dealing with this (if such a thing exists) along with some reasoning. I hope to gain an understanding, as I already have working code.

Consider the following fictional snippet:

function doStuff(data, cb) {
     if (!data) {
         return cb(new Error("Don't be an idiot"));
     }

     externalLibrary.doSomethingCallbackAsync(data, cb);
}

Were I to translate this into promise-land, I see two options.

Option 1, I can include the pre-condition in the promise.

function doStuff(data){
    return new Promise((resolve, reject) => {
        if (!data) {
            return reject(new Error("Don't be an idiot"));
        }

        externalLibrary.doSomethingCallbackAsync(data, function(err, newData) {
            if (err) {
                return reject(err);
            }
            return resolve(newData);
        });
    });
}

Option 2, I can run the pre-condition prior to the promise. I'm not certain I understand the intent of Promise.reject(), but it seems to fit the bill here by allowing me to return an immediately rejected promise.

function doStuff(data){
    if (!data) {
        return Promise.reject(new Error("Don't be an idiot"));
    }

    return new Promise((resolve, reject) => {
        externalLibrary.doSomethingCallbackAsync(data, function(err, newData) {
            if (err) {
                return reject(err);
            }
            return resolve(newData);
        });
    });
}

I prefer Option 2 for readability reasons, but I don't fully understand Promise.reject() and I am concerned that Option 2 is misusing it. Just to reiterate, I am looking for a best-practice solution.