Added more error handling

Author: robinhultman

Src/DbQueryUtility/DbQueryUtilityService.cs

@@ -23,6 +23,16 @@ public DbQueryUtilityService(IDbQueryRepository dbQueryRepository)
 
         public XPathNavigator Query(string query, string configurationKey)
         {
+            if(string.IsNullOrWhiteSpace(query))
+            {
+                throw new ArgumentNullException("query");
+            }
+
+            if(string.IsNullOrWhiteSpace(configurationKey))
+            {
+                throw new ArgumentNullException("configurationKey");
+            }
+
             var doc = _dbQueryRepository.Query(query, configurationKey);
             var nav = doc.CreateNavigator();
 

Src/DbQueryUtility/SqlDbQueryApplicationService.cs

@@ -1,6 +1,7 @@
 using BizTalkComponents.Utilities.DbQueryUtility.Repository;
 using System;
 using System.Collections.Generic;
+using System.Diagnostics;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
@@ -14,7 +15,18 @@ public XPathNavigator Query(string query, string configurationKey)
         {
             var util = new DbQueryUtilityService(new SqlDbQueryRepository());
 
-            return util.Query(query, configurationKey);
+            XPathNavigator nav;
+
+            try
+            {
+                nav = util.Query(query, configurationKey);
+            }
+            catch(Exception ex)
+            {
+                Trace.WriteLine(String.Format("An exception was thrown in DbQueryUtity. {0}", ex.ToString()));
+                throw ex;
+            }
+            return nav;
         }
     }
 }

Test/UnitTest/DbQueryServiceTest.cs

@@ -38,5 +38,20 @@ public void TestHappyPath()
             Assert.AreEqual(3, result.Select("/result/node()").Count);
             Assert.AreEqual("param2value", result.SelectSingleNode("/result/param2").Value);
         }
+
+        [TestMethod]
+        [ExpectedException(typeof(ArgumentNullException))]
+        public void TestNoConfigurationKey()
+        {
+            var result = util.Query("SELECT * FROM Test", "");
+        }
+
+        [TestMethod]
+        [ExpectedException(typeof(ArgumentNullException))]
+        public void TestNoQuery()
+        {
+            var result = util.Query("", "Key");
+        }
+
     }
 }