JavaScript链接函数，最后一个方法返回“ undefined”

Question

My app receives a base64 encoded value that is also encrypted. The data can come in a few different ways so I wanted to create chain-able methods to keep the code clean and modular.

I want to be able write: decryptionChain.decodeBase64(b64Value).stringToBuffer().finallyDecrypt();

When I run the code, the last property method "finallyDecrypt" returns as undefined.

Why is the "finallyDecrypt" method coming back as undefined? The rest all works and if I run ecryptionChain.decodeBase64(b64Value).stringToBuffer() I get back the Buffer I expect. It is only when the finallyDecrypt is chained in that I error out.

Here is the code:

   function decrypt(encrypted) {
    var decipher = crypto.createDecipheriv(algorithm, password, iv);
    decipher.setAuthTag(encrypted.tag);
    var dec = decipher.update(encrypted.content, 'hex', 'utf8');
    dec += decipher.final('utf8');
    return dec;
}

var decryptionChain = {

    currentValue:"",

    decodeBase64: function (encryptedValue){
        this.currentValue = new Buffer(encryptedValue.toString(), "base64");
        return this;
    },

    stringToBuffer: function() {
        if (this.currentValue) {
            myBuffer = JSON.parse(this.currentValue, function (key, value) {
                 return value && value.type === 'Buffer'
                    ? new Buffer(value.data)
                    : value;

            });

        }
        return myBuffer;
    },

    finallyDecrypt : function(myBuffer){
        if(myBuffer){
        decrypt(myBuffer);
        }
        return this;

    }
};

Answer 1

From the code shown, I have spotted some issues.First:

decryptionChain != decryptChain If its just a typo in the question, then disregard, if its not, please reffer to that.

Please, use the var to decrease possibilities of scope errors, or "scoped variables" being left behind.

Second, dont use a string as a Boolean .

Third, you seem to have an issue with the return value && value.type === 'Buffer' ? new Buffer(value.data) : value; return value && value.type === 'Buffer' ? new Buffer(value.data) : value; , please assign before returning (not necessary, but simpler)