(feature) add errors in case of missing filters in chan sub handlers, closes #432

Author: f3rno

lib/ws2_manager.js

@@ -334,6 +334,11 @@ module.exports = class WS2Manager extends EventEmitter {
    */
   onCandle ({ key, cbGID }, cb) {
     const s = this.getSocketWithDataChannel('candles', { key })
+
+    if (!s) {
+      throw new Error('no data socket available; did you provide a key?')
+    }
+
     s.ws.onCandle({ key, cbGID }, cb)
   }
 
@@ -354,6 +359,11 @@ module.exports = class WS2Manager extends EventEmitter {
     if (len) filter.len = len
 
     const s = this.getSocketWithDataChannel('book', filter)
+
+    if (!s) {
+      throw new Error('no data socket available; did you provide a symbol?')
+    }
+
     s.ws.onOrderBook({ cbGID, ...filter }, cb)
   }
 
@@ -366,6 +376,11 @@ module.exports = class WS2Manager extends EventEmitter {
    */
   onTrades ({ symbol, cbGID }, cb) {
     const s = this.getSocketWithDataChannel('trades', { symbol })
+
+    if (!s) {
+      throw new Error('no data socket available; did you provide a symbol?')
+    }
+
     s.ws.onTrades({ symbol, cbGID }, cb)
   }
 
@@ -378,6 +393,11 @@ module.exports = class WS2Manager extends EventEmitter {
    */
   onTicker ({ symbol = '', cbGID } = {}, cb) {
     const s = this.getSocketWithDataChannel('ticker', { symbol })
+
+    if (!s) {
+      throw new Error('no data socket available; did you provide a symbol?')
+    }
+
     s.ws.onTicker({ symbol, cbGID }, cb)
   }
 }