Fix serialization roundtrip line number test on desktop (#19473)

* Auto-format BinaryFormatterHelpers.cs

Lots of tabs were used instead of spaces

* Fix serialization roundtrip line number test on desktop

Author: stephentoub

src/Common/tests/System/Runtime/Serialization/Formatters/BinaryFormatterHelpers.cs

@@ -10,22 +10,22 @@
 
 namespace System.Runtime.Serialization.Formatters.Tests
 {
-	public static class BinaryFormatterHelpers
-	{
-		internal static T Clone<T>(T obj)
-		{
+    public static class BinaryFormatterHelpers
+    {
+        internal static T Clone<T>(T obj)
+        {
             // https://github.com/dotnet/corefx/issues/18942 - Binary serialization still WIP on AOT platforms.
             if (RuntimeInformation.FrameworkDescription.StartsWith(".NET Native"))
                 return obj;
 
-			var f = new BinaryFormatter();
-			using (var s = new MemoryStream())
-			{
-				f.Serialize(s, obj);
-				s.Position = 0;
-				return (T)f.Deserialize(s);
-			}
-		}
+            var f = new BinaryFormatter();
+            using (var s = new MemoryStream())
+            {
+                f.Serialize(s, obj);
+                s.Position = 0;
+                return (T)f.Deserialize(s);
+            }
+        }
 
         internal static Lazy<T> Clone<T>(Lazy<T> lazy)
         {
@@ -40,36 +40,36 @@ internal static Lazy<T> Clone<T>(Lazy<T> lazy)
         }
 
         public static void AssertRoundtrips<T>(T expected, params Func<T, object>[] additionalGetters)
-			where T : Exception
-		{
-			for (int i = 0; i < 2; i++)
-			{
-				if (i > 0) // first time without stack trace, second time with
-				{
-					try { throw expected; }
-					catch { }
-				}
+            where T : Exception
+        {
+            for (int i = 0; i < 2; i++)
+            {
+                if (i > 0) // first time without stack trace, second time with
+                {
+                    try { throw expected; }
+                    catch { }
+                }
 
-				// Serialize/deserialize the exception
-				T actual = Clone(expected);
+                // Serialize/deserialize the exception
+                T actual = Clone(expected);
 
-				// Verify core state
-				if (!PlatformDetection.IsFullFramework) // On full framework, line number is method body start
-				{
-				    Assert.Equal(expected.StackTrace, actual.StackTrace);
-				}
-				Assert.Equal(expected.Data, actual.Data);
-				Assert.Equal(expected.Message, actual.Message);
-				Assert.Equal(expected.Source, actual.Source);
-				Assert.Equal(expected.ToString(), actual.ToString());
-				Assert.Equal(expected.HResult, actual.HResult);
+                // Verify core state
+                if (!PlatformDetection.IsFullFramework) // On full framework, line number may be method body start
+                {
+                    Assert.Equal(expected.StackTrace, actual.StackTrace);
+                    Assert.Equal(expected.ToString(), actual.ToString()); // includes stack trace
+                }
+                Assert.Equal(expected.Data, actual.Data);
+                Assert.Equal(expected.Message, actual.Message);
+                Assert.Equal(expected.Source, actual.Source);
+                Assert.Equal(expected.HResult, actual.HResult);
 
-				// Verify optional additional state
-				foreach (Func<T, object> getter in additionalGetters)
-				{
-					Assert.Equal(getter(expected), getter(actual));
-				}
-			}
-		}
-	}
+                // Verify optional additional state
+                foreach (Func<T, object> getter in additionalGetters)
+                {
+                    Assert.Equal(getter(expected), getter(actual));
+                }
+            }
+        }
+    }
 }