Merge pull request #11 from catcherwong/iss-10-optimize-callbranch

fix: optimize callbranch with exception logic

Author: yedf2

src/Dtmcli/Constant.cs

@@ -27,7 +27,6 @@ internal class Constant
         /// </summary>
         internal static readonly string StatusAborting = "aborting";
 
-
         /// <summary>
         ///  branch type for TCC
         /// </summary>
@@ -53,6 +52,10 @@ internal class Constant
         /// </summary>
         internal static readonly string BranchRollback = "rollback";
 
+        internal static readonly string ErrFailure = "FAILRUE";
+
+        internal static readonly int FailureStatusCode = 400;
+
         internal class Request
         {
             internal static readonly string CONTENT_TYPE = "application/json";

src/Dtmcli/DtmcliException.cs

@@ -0,0 +1,12 @@
+using System;
+
+namespace Dtmcli
+{
+    public class DtmcliException : Exception
+    {
+        public DtmcliException(string message)
+            : base(message)
+        {
+        }
+    }
+}

src/Dtmcli/Tcc/Tcc.cs

@@ -35,8 +35,19 @@ public async Task<string> CallBranch(object body, string tryUrl, string confirmU
                 Constant.BranchTry,
                 tryUrl,
                 cancellationToken).ConfigureAwait(false);
-          
-            return await response.Content.ReadAsStringAsync().ConfigureAwait(false);
+
+            var content = await response.Content.ReadAsStringAsync().ConfigureAwait(false);
+
+            // call branch error should throw exception
+            var isOldVerException = response.StatusCode == System.Net.HttpStatusCode.OK && content.Contains(Constant.ErrFailure);
+            var isNewVerException = (int)response.StatusCode >= Constant.FailureStatusCode;
+
+            if (isOldVerException || isNewVerException)
+            {
+                throw new DtmcliException("An exception occurred when CallBranch");
+            }
+
+            return content;
         }
 
         public DtmImp.TransBase GetTransBase() => _transBase;