util.js

'user strict'

/*
@author Akash Singh
@email contact@akashsingh.io
@web akashsingh.io
*/

function arrayBufferToBase64(buffer) {
    var binary = '';
    var bytes = new Uint8Array(buffer);
    var len = bytes.byteLength;
    for (var i = 0; i < len; i++) {
        binary += String.fromCharCode( bytes[ i ] );
    }
    return window.btoa(binary);
}

function base64ToArrayBuffer(base64) {
    var binary_string =  window.atob(base64);
    var len = binary_string.length;
    var bytes = new Uint8Array(len);
    for (var i = 0; i < len; i++)        {
        bytes[i] = binary_string.charCodeAt(i);
    }
    return bytes.buffer;
}

function sendRequest(url, reqObj) {
    return fetch(url, {
        method: 'POST',
        headers: {
            'Accept': 'application/json',
            'Content-Type': 'application/json'
        },
        body: JSON.stringify(reqObj)
    })
    .then(res => {
        return res.json();
    })
    .catch(err => {
        console.log(err);
    })
}

// Util import from src/helpers.js
var util = (function() {
    'use strict';

    var StaticArrayBufferProto = new ArrayBuffer().__proto__;

    return {
        toString: function(thing) {
            if (typeof thing == 'string') {
                return thing;
            }
            return new dcodeIO.ByteBuffer.wrap(thing).toString('binary');
        },
        toArrayBuffer: function(thing) {
            if (thing === undefined) {
                return undefined;
            }
            if (thing === Object(thing)) {
                if (thing.__proto__ == StaticArrayBufferProto) {
                    return thing;
                }
            }

            var str;
            if (typeof thing == "string") {
                str = thing;
            } else {
                throw new Error("Tried to convert a non-string of type " + typeof thing + " to an array buffer");
            }
            return new dcodeIO.ByteBuffer.wrap(thing, 'binary').toArrayBuffer();
        },
        isEqual: function(a, b) {
            // TODO: Special-case arraybuffers, etc
            if (a === undefined || b === undefined) {
                return false;
            }
            a = util.toString(a);
            b = util.toString(b);
            var maxLength = Math.max(a.length, b.length);
            if (maxLength < 5) {
                throw new Error("a/b compare too short");
            }
            return a.substring(0, Math.min(maxLength, a.length)) == b.substring(0, Math.min(maxLength, b.length));
        }
    };
})();

window.util = util;
window.arrBuffToBase64 = arrayBufferToBase64;
window.base64ToArrBuff = base64ToArrayBuffer;
window.sendRequest = sendRequest;