Add some regression tests

Author: ericstj

src/Microsoft.DotNet.CodeFormatting.Tests/Rules/CombinationTest.cs

@@ -357,5 +357,69 @@ public void RequiredRuntimeAttribute()
             ToggleRule(UsingLocationRule.Name, enabled: true);
             Verify(source, expected);
         }
+
+        [Fact]
+        public void Issue268()
+        {
+            var text = @"
+using System.Collections.Generic;
+
+internal class C
+{
+    private void M<TValue>()
+    {
+        Dictionary<string, Stack<TValue>> dict = new Dictionary<string, Stack<TValue>>();
+        dict.TryGetValue(""key"", out Stack<TValue> stack);
+    }
+}";
+
+            Verify(text, expected:text);
+        }
+
+        [Fact]
+        public void Issue272()
+        {
+            var text = @"
+using System.Collections.Generic;
+
+internal class C
+{
+
+        private object myVariable;
+
+        private void M()
+        {
+            Dictionary<string, object> dict = new Dictionary<string, object>()
+            {
+                { ""key"", new object() }
+            };
+
+            dict.TryGetValue(""key"", out object myVariable);
+
+            this.myVariable = myVariable;
+        }
+}";
+            var expected = @"
+using System.Collections.Generic;
+
+internal class C
+{
+    private object _myVariable;
+
+    private void M()
+    {
+        Dictionary<string, object> dict = new Dictionary<string, object>()
+            {
+                { ""key"", new object() }
+            };
+
+        dict.TryGetValue(""key"", out object myVariable);
+
+        _myVariable = myVariable;
+    }
+}";
+
+            Verify(text, expected);
+        }
     }
 }

src/Microsoft.DotNet.CodeFormatting.Tests/Rules/PrivateFieldNamingRuleTests.cs

@@ -211,6 +211,58 @@ int M(C p)
 
                 Verify(text, expected);
             }
+
+            [Fact]
+            public void Issue258()
+            {
+                var text = @"
+class C
+{
+    private (string name, string value) myTuple;
+}
+";
+                var expected = @"
+class C
+{
+    private (string name, string value) _myTuple;
+}
+";
+
+                Verify(text, expected, runFormatter: false);
+            }
+
+            [Fact]
+            public void Issue241()
+            {
+                var text = @"
+class C
+{
+        private bool streamObjects;
+
+        /// <summary>
+        /// A collection in which objects that are written using the WriteError
+        /// method are accumulated if <see cref=""streamObjects"" /> is false.
+        /// </summary>
+        private List<string> errors;
+        
+}
+";
+                var expected = @"
+class C
+{
+        private bool _streamObjects;
+
+        /// <summary>
+        /// A collection in which objects that are written using the WriteError
+        /// method are accumulated if <see cref=""_streamObjects"" /> is false.
+        /// </summary>
+        private List<string> _errors;
+        
+}
+";
+
+                Verify(text, expected, runFormatter: false);
+            }
         }
 
         public sealed class VisualBasicFields : PrivateFieldNamingRuleTests