GateIo - Add the missing volume data OnGetTickerAsync and OnGetTickersAsync (#862)

Author: BZ-CO

src/ExchangeSharp/API/Exchanges/GateIo/ExchangeGateIoAPI.cs

@@ -41,13 +41,24 @@ protected override async Task<
 				IEnumerable<KeyValuePair<string, ExchangeTicker>>
 		> OnGetTickersAsync()
 		{
-			var json = await MakeJsonRequestAsync<JToken>("/spot/tickers");
+			var response = await MakeJsonRequestAsync<JToken>("/spot/tickers");
+			var tickers =
+				new List<KeyValuePair<string, ExchangeTicker>>();
 
-			var tickers = json.Select(tickerToken => ParseTicker(tickerToken))
-					.Select(
-							ticker => new KeyValuePair<string, ExchangeTicker>(ticker.MarketSymbol, ticker)
-					)
-					.ToList();
+			foreach (var t in response)
+			{
+				var marketSymbol = t["currency_pair"].ToStringInvariant();
+				tickers.Add(new KeyValuePair<string, ExchangeTicker>(
+					marketSymbol,
+					await this.ParseTickerAsync(
+						t,
+						t["currency_pair"].ToStringInvariant(),
+						"lowest_ask",
+						"highest_bid",
+						"last",
+						"base_volume",
+						"quote_volume")));
+			}
 
 			return tickers;
 		}
@@ -171,44 +182,9 @@ protected internal override async Task<
 		protected override async Task<ExchangeTicker> OnGetTickerAsync(string symbol)
 		{
 			var json = await MakeJsonRequestAsync<JToken>($"/spot/tickers?currency_pair={symbol}");
-			return ParseTicker(json.First());
-		}
-
-		private ExchangeTicker ParseTicker(JToken tickerToken)
-		{
-			bool IsEmptyString(JToken token) =>
-					token.Type == JTokenType.String && token.ToObject<string>() == string.Empty;
 
-			/*
-					{
-							"currency_pair": "BTC3L_USDT",
-							"last": "2.46140352",
-							"lowest_ask": "2.477",
-							"highest_bid": "2.4606821",
-							"change_percentage": "-8.91",
-							"base_volume": "656614.0845820589",
-							"quote_volume": "1602221.66468375534639404191",
-							"high_24h": "2.7431",
-							"low_24h": "1.9863",
-							"etf_net_value": "2.46316141",
-							"etf_pre_net_value": "2.43201848",
-							"etf_pre_timestamp": 1611244800,
-							"etf_leverage": "2.2803019447281203"
-					}
-			*/
-
-			return new ExchangeTicker
-			{
-				Exchange = Name,
-				MarketSymbol = tickerToken["currency_pair"].ToStringInvariant(),
-				Bid = IsEmptyString(tickerToken["lowest_ask"])
-							? default
-							: tickerToken["lowest_ask"].ConvertInvariant<decimal>(),
-				Ask = IsEmptyString(tickerToken["highest_bid"])
-							? default
-							: tickerToken["highest_bid"].ConvertInvariant<decimal>(),
-				Last = tickerToken["last"].ConvertInvariant<decimal>(),
-			};
+			return await this.ParseTickerAsync(json.First(), json.First()["currency_pair"].ToStringInvariant(), "lowest_ask",
+				"highest_bid", "last", "base_volume", "quote_volume");
 		}
 
 		protected override async Task<ExchangeOrderBook> OnGetOrderBookAsync(