Fix DW connection bug (#258)

- Connection info cache is now per-DB instead of per-server. This has the downside of increasing #queries, but is required in order to correctly handle isSqlDW since this changes for each database on an Azure server.

test/Microsoft.SqlTools.ServiceLayer.Test/Connection/CachedServerInfoTests.cs

@@ -6,6 +6,7 @@
 using System;
 using Xunit;
 using Microsoft.SqlTools.ServiceLayer.Connection.ReliableConnection;
+using System.Data.SqlClient;
 
 namespace Microsoft.SqlTools.ServiceLayer.Test.Connection
 {
@@ -14,18 +15,70 @@ namespace Microsoft.SqlTools.ServiceLayer.Test.Connection
     /// </summary>
     public class CachedServerInfoTests
     {
+        private CachedServerInfo cache;
+
+        public CachedServerInfoTests()
+        {
+            cache = new CachedServerInfo();
+        }
+
+        [Fact]
+        public void CacheMatchesNullDbNameToEmptyString()
+        {
+            // Set sqlDw result into cache
+            string dataSource = "testDataSource";
+            bool isSqlDwResult;
+            SqlConnectionStringBuilder testSource = new SqlConnectionStringBuilder
+            {
+                DataSource = dataSource,
+                InitialCatalog = string.Empty
+            };
+            cache.AddOrUpdateCache(testSource, true, CachedServerInfo.CacheVariable.IsSqlDw);
+
+            // Expect the same returned result
+            Assert.True(cache.TryGetIsSqlDw(testSource, out isSqlDwResult));
+            Assert.True(isSqlDwResult);
+
+            // And expect the same for the null string
+            Assert.True(cache.TryGetIsSqlDw(new SqlConnectionStringBuilder
+            {
+                DataSource = dataSource
+                // Initial Catalog is null. Can't set explicitly as this throws
+            }, out isSqlDwResult));
+            Assert.True(isSqlDwResult);
+
+            // But expect false for a different DB
+            Assert.False(cache.TryGetIsSqlDw(new SqlConnectionStringBuilder
+            {
+                DataSource = dataSource,
+                InitialCatalog = "OtherDb"
+            }, out isSqlDwResult));
+        }
 
         [Theory]
-        [InlineData(true)]  // is SqlDW instance
-        [InlineData(false)]   // is not a SqlDw Instance
-        public void AddOrUpdateIsSqlDw(bool state)
+        [InlineData(null, true)]  // is SqlDW instance
+        [InlineData("", true)]  // is SqlDW instance
+        [InlineData("myDb", true)]  // is SqlDW instance
+        [InlineData(null, false)]   // is not a SqlDw Instance
+        [InlineData("", false)]   // is not a SqlDw Instance
+        [InlineData("myDb", false)]  // is not SqlDW instance
+        public void AddOrUpdateIsSqlDw(string dbName, bool state)
         {
             // Set sqlDw result into cache
             bool isSqlDwResult;
-            CachedServerInfo.AddOrUpdateCache("testDataSource", state, CachedServerInfo.CacheVariable.IsSqlDw);
+            SqlConnectionStringBuilder testSource = new SqlConnectionStringBuilder
+            {
+                DataSource = "testDataSource"
+            };
+            if (dbName != null)
+            {
+                testSource.InitialCatalog = dbName;
+            }
+
+            cache.AddOrUpdateCache(testSource, state, CachedServerInfo.CacheVariable.IsSqlDw);
 
             // Expect the same returned result
-            Assert.True(CachedServerInfo.TryGetIsSqlDw("testDataSource", out isSqlDwResult));
+            Assert.True(cache.TryGetIsSqlDw(testSource, out isSqlDwResult));
             Assert.Equal(isSqlDwResult, state);
         }
 
@@ -36,18 +89,22 @@ namespace Microsoft.SqlTools.ServiceLayer.Test.Connection
         {
             // Set sqlDw result into cache
             bool isSqlDwResult;
-            CachedServerInfo.AddOrUpdateCache("testDataSource", state, CachedServerInfo.CacheVariable.IsSqlDw);
+            SqlConnectionStringBuilder testSource = new SqlConnectionStringBuilder
+            {
+                DataSource = "testDataSource"
+            };
+            cache.AddOrUpdateCache(testSource, state, CachedServerInfo.CacheVariable.IsSqlDw);
 
             // Expect the same returned result
-            Assert.True(CachedServerInfo.TryGetIsSqlDw("testDataSource", out isSqlDwResult));
+            Assert.True(cache.TryGetIsSqlDw(testSource, out isSqlDwResult));
             Assert.Equal(isSqlDwResult, state);
 
             // Toggle isSqlDw cache state
             bool isSqlDwResultToggle;
-            CachedServerInfo.AddOrUpdateCache("testDataSource", !state, CachedServerInfo.CacheVariable.IsSqlDw);
+            cache.AddOrUpdateCache(testSource, !state, CachedServerInfo.CacheVariable.IsSqlDw);
 
             // Expect the oppisite returned result
-            Assert.True(CachedServerInfo.TryGetIsSqlDw("testDataSource", out isSqlDwResultToggle));
+            Assert.True(cache.TryGetIsSqlDw(testSource, out isSqlDwResultToggle));
             Assert.Equal(isSqlDwResultToggle, !state);
 
         }
@@ -56,19 +113,40 @@ namespace Microsoft.SqlTools.ServiceLayer.Test.Connection
         public void AddOrUpdateIsSqlDwFalseToggle()
         {
             bool state = true;
+
+            SqlConnectionStringBuilder testSource = new SqlConnectionStringBuilder
+            {
+                DataSource = "testDataSource"
+            };
+
+            SqlConnectionStringBuilder sameServerDifferentDb = new SqlConnectionStringBuilder
+            {
+                DataSource = "testDataSource",
+                InitialCatalog = "myDb"          
+            };
+            SqlConnectionStringBuilder differentServerSameDb = new SqlConnectionStringBuilder
+            {
+                DataSource = "testDataSource2",
+                InitialCatalog = ""
+            };
+
+            cache.AddOrUpdateCache(testSource, state, CachedServerInfo.CacheVariable.IsSqlDw);
+            cache.AddOrUpdateCache(sameServerDifferentDb, !state, CachedServerInfo.CacheVariable.IsSqlDw);
+            cache.AddOrUpdateCache(differentServerSameDb, !state, CachedServerInfo.CacheVariable.IsSqlDw);
+
+            // Expect the same returned result
             // Set sqlDw result into cache
             bool isSqlDwResult;
             bool isSqlDwResult2;
-            CachedServerInfo.AddOrUpdateCache("testDataSource", state, CachedServerInfo.CacheVariable.IsSqlDw);
-            CachedServerInfo.AddOrUpdateCache("testDataSource2", !state, CachedServerInfo.CacheVariable.IsSqlDw);
-
-            // Expect the same returned result
-            Assert.True(CachedServerInfo.TryGetIsSqlDw("testDataSource", out isSqlDwResult));
-            Assert.True(CachedServerInfo.TryGetIsSqlDw("testDataSource2", out isSqlDwResult2));
+            bool isSqlDwResult3;
+            Assert.True(cache.TryGetIsSqlDw(testSource, out isSqlDwResult));
+            Assert.True(cache.TryGetIsSqlDw(sameServerDifferentDb, out isSqlDwResult2));
+            Assert.True(cache.TryGetIsSqlDw(differentServerSameDb, out isSqlDwResult3));
 
             // Assert cache is set on a per connection basis
             Assert.Equal(isSqlDwResult, state);
             Assert.Equal(isSqlDwResult2, !state);
+            Assert.Equal(isSqlDwResult3, !state);
 
         }
 
@@ -76,7 +154,11 @@ namespace Microsoft.SqlTools.ServiceLayer.Test.Connection
         public void AskforSqlDwBeforeCached()
         {
             bool isSqlDwResult;
-            Assert.False(CachedServerInfo.TryGetIsSqlDw("testDataSourceWithNoCache", out isSqlDwResult));
+            Assert.False(cache.TryGetIsSqlDw(new SqlConnectionStringBuilder
+            {
+                DataSource = "testDataSourceUnCached"
+            }, 
+            out isSqlDwResult));
         }
     }
 }