Many improvements

Author: Jon Eyrick

README.md

@@ -125,9 +125,12 @@ binance.prices((error, ticker) => {
 #### Getting list of current balances
 ```javascript
 binance.balance((error, balances) => {
+  if ( error ) return console.error(error);
   console.log("balances()", balances);
   console.log("ETH balance: ", balances.ETH.available);
 });
+// If you have problems with this function,
+// see Troubleshooting at the bottom of this page.
 ```
 <details>
  <summary>View Response</summary>
@@ -1637,6 +1640,17 @@ binance.options({
 });
 ```
 
+Problems getting your balance? Wrap the entry point of your application in useServerTime:
+```js
+binance.useServerTime(function() {
+	binance.balance((error, balances) => {
+		if ( error ) return console.error(error);
+		console.log("balances()", balances);
+		console.log("BNB balance: ", balances.BNB.available);
+	});
+});
+```
+
 [![Views](http://hits.dwyl.io/jaggedsoft/node-binance-api.svg)](http://hits.dwyl.io/jaggedsoft/node-binance-api)
 
 Thank you to all contributors: dmzoneill, dmitriz, keith1024, usama33, yanislk, learnathoner, vaielab, nickreese, Tuitio, grandmore, itnok, CollinEstes, sethyx, mstijak, MadDeveloper, balthazar, bitoiu, matthewwoop, robaleman, hems and others!

examples/subscribe-to-all.js

@@ -0,0 +1,31 @@
+const Binance = require('node-binance-api');
+const binance = new Binance().options('options.json');
+global.ticker = {};
+
+// Get all symbols
+binance.prevDay(false, (error, prevDay) => {
+    if ( error ) return console.log(error.body);
+    let markets = [];
+    for ( let obj of prevDay ) {
+        let symbol = obj.symbol;
+
+        // Filter BTC & USDT markets only (example)
+        if ( !symbol.endsWith('BTC') && !symbol.endsWith('USDT') ) continue;
+
+        console.log(`${symbol} price: ${obj.lastPrice} volume: ${obj.volume} change: ${obj.priceChangePercent}%`);
+        global.ticker[symbol] = obj.lastPrice;
+        markets.push(symbol);
+    }
+
+    // Subscribe to trades endpoint for all markets
+    binance.websockets.trades(markets, (trades) => {
+        let { e: eventType, E: eventTime, s: symbol, p: price, q: quantity, m: maker, a: tradeId } = trades;
+        console.log(`${symbol} price: ${price}`);
+        global.ticker[symbol] = price;
+    });
+
+    // You can use global.ticker anywhere in your program now
+    setInterval(() => {
+        console.log("*** Price of BTC: " + global.ticker.BTCUSDT);
+    }, 3000);
+});

node-binance-api.js

@@ -313,14 +313,14 @@ let api = function Binance() {
      */
     const handleSocketClose = function (reconnect, code, reason) {
         delete Binance.subscriptions[this.endpoint];
-        if (Object.keys(Binance.subscriptions).length === 0) {
+        if ( Binance.subscriptions && Object.keys(Binance.subscriptions).length === 0 ) {
             clearInterval(Binance.socketHeartbeatInterval);
         }
         Binance.options.log('WebSocket closed: ' + this.endpoint +
             (code ? ' (' + code + ')' : '') +
             (reason ? ' ' + reason : ''));
-        if (Binance.options.reconnect && this.reconnect && reconnect) {
-            if (parseInt(this.endpoint.length, 10) === 60) Binance.options.log('Account data WebSocket reconnecting...');
+        if ( Binance.options.reconnect && this.reconnect && reconnect) {
+            if ( this.endpoint && parseInt(this.endpoint.length, 10) === 60) Binance.options.log('Account data WebSocket reconnecting...');
             else Binance.options.log('WebSocket reconnecting: ' + this.endpoint + '...');
             try {
                 reconnect();
@@ -336,7 +336,6 @@ let api = function Binance() {
      * @return {undefined}
      */
     const handleSocketError = function (error) {
-
         /* Errors ultimately result in a `close` event.
            see: https://github.com/websockets/ws/blob/828194044bf247af852b31c49e2800d557fedeff/lib/websocket.js#L126 */
         Binance.options.log('WebSocket error: ' + this.endpoint +
@@ -814,26 +813,26 @@ let api = function Binance() {
 
         /**
         * rounds number with given step
-        * @param {float} number - quantity to round
+        * @param {float} qty - quantity to round
         * @param {float} stepSize - stepSize as specified by exchangeInfo
         * @return {float} - number
         */
-        roundStep: function (number, stepSize) {
+        roundStep: function (qty, stepSize) {
             const precision = stepSize.toString().split('.')[1].length || 0;
-            return (((number / stepSize) | 0) * stepSize).toFixed(precision);
+            return (((qty / stepSize) | 0) * stepSize).toFixed(precision);
         },
-        
+
         /**
         * rounds price to required precision
-        * @param {float} number - price to round
+        * @param {float} price - price to round
         * @param {float} tickSize - tickSize as specified by exchangeInfo
         * @return {float} - number
         */
-        roundTicks: function (number, tickSize) {
+        roundTicks: function (price, tickSize) {
             const formatter = new Intl.NumberFormat('en-US', { style: 'decimal', minimumFractionDigits: 0, maximumFractionDigits: 8 });
             const precision = formatter.format(tickSize).split('.')[1].length || 0;
-            if ( typeof number === 'string' ) number = parseFloat(number);
-            return number.toFixed(precision);
+            if ( typeof price === 'string' ) price = parseFloat(price);
+            return price.toFixed(precision);
         },
 
         /**
@@ -1703,7 +1702,7 @@ let api = function Binance() {
                         let context = Binance.depthCacheContext[symbol];
                         context.endpointId = endpointId;
                     }
-                }
+                };
 
                 let handleDepthStreamData = function (depth) {
                     let symbol = depth.s;
@@ -1788,6 +1787,29 @@ let api = function Binance() {
                 return subscription.endpoint;
             },
 
+            /**
+             * Websocket staggered depth cache
+             * @param {array/string} symbols - an array of symbols to query
+             * @param {function} callback - callback function
+             * @param {int} limit - the number of entries
+             * @param {int} stagger - ms between each depth cache
+             * @return {Promise} the websocket endpoint
+             */
+            depthCacheStaggered: function(symbols, callback, limit=100, stagger=200) {
+                if (!Array.isArray(symbols)) symbols = [symbols];
+                let chain = null;
+
+                symbols.forEach(symbol => {
+                    let promise = () => new Promise(resolve => {
+                        this.depthCache(symbol, callback, limit);
+                        setTimeout(resolve, stagger);
+                    });
+                    chain = chain ? chain.then(promise) : promise();
+                });
+
+                return chain;
+            },
+
             /**
             * Websocket aggregated trades
             * @param {array/string} symbols - an array or string of symbols to query

package.json

@@ -1,6 +1,6 @@
 {
   "name": "node-binance-api",
-  "version": "0.8.3",
+  "version": "0.8.4",
   "description": "Binance API for node https://github.com/jaggedsoft/node-binance-api",
   "main": "node-binance-api.js",
   "dependencies": {

test.js

@@ -1124,6 +1124,72 @@ describe('Websockets array depthcache', function () {
   });
 });
 
+describe('Staggered websockets symbol depthcache', function () {
+    let symbol;
+    let bids;
+    let asks;
+    let cnt = 0;
+    beforeEach(function (done) {
+        this.timeout(TIMEOUT);
+        binance.websockets.depthCacheStaggered('BNBBTC', (a_symbol, a_depth) => {
+            cnt++;
+            if (cnt > 1) return;
+            stopSockets(true);
+            symbol = a_symbol;
+            bids = a_depth.bids;
+            asks = a_depth.asks;
+            done();
+        });
+    });
+
+    bids = binance.sortBids(bids);
+    asks = binance.sortAsks(asks);
+
+    it('check result of depth cache', function () {
+        assert(typeof (bids) === 'object', WARN_SHOULD_BE_OBJ);
+        assert(typeof (asks) === 'object', WARN_SHOULD_BE_OBJ);
+        assert(typeof (symbol) === 'string', WARN_SHOULD_BE_OBJ);
+        assert(bids !== null, WARN_SHOULD_BE_NOT_NULL);
+        assert(asks !== null, WARN_SHOULD_BE_NOT_NULL);
+        assert(symbol !== null, WARN_SHOULD_BE_NOT_NULL);
+        assert(Object.keys(asks).length !== 0, 'should not be 0');
+        assert(Object.keys(bids).length !== 0, 'should not be 0');
+    });
+});
+
+describe('Staggered Websockets array depthcache', function () {
+    let symbol;
+    let bids;
+    let asks;
+    let cnt = 0;
+    beforeEach(function (done) {
+        this.timeout(TIMEOUT);
+        binance.websockets.depthCacheStaggered(['BNBBTC', 'TRXBTC'], (a_symbol, a_depth) => {
+            cnt++;
+            if (cnt > 1) return;
+            stopSockets();
+            symbol = a_symbol;
+            bids = a_depth.bids;
+            asks = a_depth.asks;
+            done();
+        });
+    });
+
+    bids = binance.sortBids(bids);
+    asks = binance.sortAsks(asks);
+
+    it('check result of symbols array depth cache', function () {
+        assert(typeof (bids) === 'object', WARN_SHOULD_BE_OBJ);
+        assert(typeof (asks) === 'object', WARN_SHOULD_BE_OBJ);
+        assert(typeof (symbol) === 'string', WARN_SHOULD_BE_OBJ);
+        assert(bids !== null, WARN_SHOULD_BE_NOT_NULL);
+        assert(asks !== null, WARN_SHOULD_BE_NOT_NULL);
+        assert(symbol !== null, WARN_SHOULD_BE_NOT_NULL);
+        assert(Object.keys(asks).length !== 0, 'should not be 0');
+        assert(Object.keys(bids).length !== 0, 'should not be 0');
+    });
+});
+
 describe('Websockets prevDay', function () {
   let response;
   let cnt = 0;