Adds IndentedStringBuilder (#499)

src/Microsoft.Health.Fhir.SqlServer.UnitTests/IndentedStringBuilderTests.cs

@@ -0,0 +1,36 @@
+// -------------------------------------------------------------------------------------------------
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License (MIT). See LICENSE in the repo root for license information.
+// -------------------------------------------------------------------------------------------------
+
+using System;
+using System.Text;
+using Xunit;
+
+namespace Microsoft.Health.Fhir.SqlServer.UnitTests
+{
+    public class IndentedStringBuilderTests
+    {
+        [Fact]
+        public void GivenAnIndentedStringBuilder_WhenUsingIndentedScopes_KeepsTrackOfIndentation()
+        {
+            var sb = new IndentedStringBuilder(new StringBuilder())
+                .AppendLine("class Foo").AppendLine("{");
+
+            using (sb.Indent())
+            {
+                sb.AppendLine("Foo()").AppendLine("{");
+                using (sb.Indent())
+                {
+                    sb.Append("// ").AppendLine("hello");
+                }
+
+                sb.AppendLine("}");
+            }
+
+            sb.Append("}");
+
+            Assert.Equal($"class Foo{Environment.NewLine}{{{Environment.NewLine}    Foo(){Environment.NewLine}    {{{Environment.NewLine}        // hello{Environment.NewLine}    }}{Environment.NewLine}}}", sb.ToString());
+        }
+    }
+}