diff --git a/Src/SwqlStudio/ObjectExplorer/StringBuilderExtensions.cs b/Src/SwqlStudio/ObjectExplorer/StringBuilderExtensions.cs
index 547c587bf..2dfca612d 100644
--- a/Src/SwqlStudio/ObjectExplorer/StringBuilderExtensions.cs
+++ b/Src/SwqlStudio/ObjectExplorer/StringBuilderExtensions.cs
@@ -8,49 +8,89 @@ internal static class StringBuilderExtensions
     {
         public static void AppendName(this StringBuilder builder, string name)
         {
-            builder.AppendFormat("Name: {0}\r\n", name);
+            if (builder == null)
+            {
+                throw new ArgumentNullException(nameof(builder));
+            }
+
+            builder.AppendFormat("Name: {0}{1}", name, Environment.NewLine);
         }
 
         public static void AppendType(this StringBuilder builder, string metadataType)
         {
-            builder.AppendFormat("Type: {0}\r\n", metadataType);
+            if (builder == null)
+            {
+                throw new ArgumentNullException(nameof(builder));
+            }
+
+            builder.AppendFormat("Type: {0}{1}", metadataType, Environment.NewLine);
         }
 
         public static void AppendSummaryParagraph(this StringBuilder builder, string summary)
         {
-            builder.Append("\r\n\r\n");
+            if (builder == null)
+            {
+                throw new ArgumentNullException(nameof(builder));
+            }
+
+            builder.AppendLine();
+            builder.AppendLine();
             builder.AppendSummary(summary);
         }
 
         public static void AppendSummary(this StringBuilder builder, string summary)
         {
+            if (builder == null)
+            {
+                throw new ArgumentNullException(nameof(builder));
+            }
+
             if (string.IsNullOrEmpty(summary))
+            {
                 return;
+            }
 
-            var trimmed = summary.Trim();
-            builder.AppendFormat(trimmed);
+            string trimmed = summary.Trim();
+            builder.Append(trimmed);
         }
 
         public static void AppendAccessControl(this StringBuilder builder, ConnectionInfo connection, Entity entity)
         {
+            if (entity == null)
+            {
+                throw new ArgumentNullException(nameof(entity));
+            }
+
+            if (connection == null)
+            {
+                throw new ArgumentNullException(nameof(connection));
+            }
+
+
             if (entity.IsIndication)
             {
+
                 builder.Append($@"Can Subscribe: {connection.CanCreateSubscription}");
             }
             else
             {
-                builder.Append($"Can Read: {entity.CanRead}\r\n");
-                builder.Append($"Can Create: {entity.CanCreate}\r\n");
-                builder.Append($"Can Update: {entity.CanUpdate}\r\n");
-                builder.Append($"Can Delete: {entity.CanDelete}\r\n");
+                builder.AppendLine($"Can Read: {entity.CanRead}");
+                builder.AppendLine($"Can Create: {entity.CanCreate}");
+                builder.AppendLine($"Can Update: {entity.CanUpdate}");
+                builder.AppendLine($"Can Delete: {entity.CanDelete}");
             }
         }
 
         public static void AppendObsoleteSection(this StringBuilder builder, IObsoleteMetadata entity)
         {
+            if (builder == null)
+            {
+                throw new ArgumentNullException(nameof(builder));
+            }
+
             if (entity != null && entity.IsObsolete)
             {
-                builder.Append($"Obsolete: {entity.ObsolescenceReason}{Environment.NewLine}");
+                builder.AppendLine($"Obsolete: {entity.ObsolescenceReason}");
             }
         }
     }
diff --git a/Test/SwqlStudio.Tests/AutocompleteProviderTest.cs b/Test/SwqlStudio.Tests/AutocompleteProviderTest.cs
index d31c7c669..24a668cf9 100644
--- a/Test/SwqlStudio.Tests/AutocompleteProviderTest.cs
+++ b/Test/SwqlStudio.Tests/AutocompleteProviderTest.cs
@@ -1,8 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
+using System.Collections.Generic;
 using FluentAssertions;
 using SwqlStudio.Autocomplete;
 using Xunit;
diff --git a/Test/SwqlStudio.Tests/AutocompleteTokenizerTest.cs b/Test/SwqlStudio.Tests/AutocompleteTokenizerTest.cs
index e822c945c..8cf5fa718 100644
--- a/Test/SwqlStudio.Tests/AutocompleteTokenizerTest.cs
+++ b/Test/SwqlStudio.Tests/AutocompleteTokenizerTest.cs
@@ -1,8 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
+using System.Collections.Generic;
 using FluentAssertions;
 using SwqlStudio.Autocomplete;
 using Xunit;
diff --git a/Test/SwqlStudio.Tests/StringBuilderExtensionsTests.cs b/Test/SwqlStudio.Tests/StringBuilderExtensionsTests.cs
new file mode 100644
index 000000000..1f19e3c7e
--- /dev/null
+++ b/Test/SwqlStudio.Tests/StringBuilderExtensionsTests.cs
@@ -0,0 +1,152 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+using SwqlStudio.Metadata;
+using Xunit;
+
+namespace SwqlStudio.Tests
+{
+    public class StringBuilderExtensionsTests
+    {
+        [Fact]
+        public void AllMethodsThrowExceptionOnNullBuilder()
+        {
+            StringBuilder stringBuilder = null;
+            var methods = new List<Action>
+            {
+                () => stringBuilder.AppendName(string.Empty),
+                () => stringBuilder.AppendType(string.Empty),
+                () => stringBuilder.AppendObsoleteSection(null),
+                () => stringBuilder.AppendSummary(string.Empty),
+                () => stringBuilder.AppendSummaryParagraph(string.Empty),
+                () => stringBuilder.AppendAccessControl(null, null),
+            };
+
+            foreach (Action method in methods)
+            {
+                Assert.Throws<ArgumentNullException>(() =>
+                {
+                    method();
+                });    
+            }
+        }
+
+        [Theory]
+        [MemberData(nameof(AppendSummaryTrimsInputTestCases))]
+        public void AppendSummaryTests(string input, string expected)
+        {
+            TestAppendMethod(input, expected, (s, stringB) => stringB.AppendSummary(s));
+        }
+
+        public static IEnumerable<object[]> AppendSummaryTrimsInputTestCases = new List<object[]>
+        {
+            new object[]{ "a", "a"},
+            new object[]{ "a ", "a"},
+            new object[]{ " a", "a"},
+            new object[]{ null, ""},
+            new object[]{ string.Empty, ""},
+            new object[]{ "  a", "a"},
+            new object[]{ "a {0} ", "a {0}"}
+        };
+
+        [Theory]
+        [MemberData(nameof(AppendSummaryParagraphTestCases))]
+        public void AppendSummaryParagraphTests(string input, string expected)
+        {
+            TestAppendMethod(input, expected, (s, stringB) => stringB.AppendSummaryParagraph(s));
+        }
+
+        public static IEnumerable<object[]> AppendSummaryParagraphTestCases = new List<object[]>
+        {
+            new object[]{ "a ", $"{Environment.NewLine}{Environment.NewLine}a"},
+            new object[]{ " ", $"{Environment.NewLine}{Environment.NewLine}"}
+        };
+
+
+        [Theory]
+        [MemberData(nameof(AppendNameTestCases))]
+        public void AppendNameTests(string input, string expected)
+        {
+            TestAppendMethod(input, expected, (s, stringB) => stringB.AppendName(s));
+        }
+
+        public static IEnumerable<object[]> AppendNameTestCases = new List<object[]>
+        {
+            new object[]{ "a", $"Name: a{Environment.NewLine}"},
+            new object[]{ string.Empty, $"Name: {Environment.NewLine}"},
+        };
+
+        [Theory]
+        [MemberData(nameof(AppendTypeTestCases))]
+        public void AppendTypeTests(string input, string expected)
+        {
+            TestAppendMethod(input, expected, (s, stringB) => stringB.AppendType(s));
+        }
+
+        public static IEnumerable<object[]> AppendTypeTestCases = new List<object[]>
+        {
+            new object[]{ "a", $"Type: a{Environment.NewLine}"},
+            new object[]{ string.Empty, $"Type: {Environment.NewLine}"},
+        };
+
+        [Theory]
+        [MemberData(nameof(AppendObsoleteSectionTestCases))]
+        public void AppendObsoleteSectionTests(string input, string expected, bool isObsolete)
+        {
+            IObsoleteMetadata entity = new Entity { IsObsolete = isObsolete, ObsolescenceReason = input };
+            TestAppendMethod(input, expected, (s, stringB) => stringB.AppendObsoleteSection(entity));
+        }
+
+        public static IEnumerable<object[]> AppendObsoleteSectionTestCases = new List<object[]>
+        {
+            new object[]{ "a", $"Obsolete: a{Environment.NewLine}", true},
+            new object[]{ string.Empty, $"Obsolete: {Environment.NewLine}", true},
+            new object[]{ string.Empty, string.Empty, false},
+        };
+
+        [Fact]
+        public void AppendAccessControlTests_IsIndication()
+        {
+            var stringBuilder = new StringBuilder();
+
+            var connectionInfo = new ConnectionInfo("localhost", "admin", "pass", "orion");
+            var entity = new Entity { IsIndication = true };
+
+            stringBuilder.AppendAccessControl(connectionInfo, entity);
+
+            var result = stringBuilder.ToString();
+
+            Assert.Equal("Can Subscribe: False", result);
+        }
+
+        [Fact]
+        public void AppendAccessControlTests_NotIndication()
+        {
+            var stringBuilder = new StringBuilder();
+
+            var connectionInfo = new ConnectionInfo("localhost", "admin", "pass", "orion");
+            var entity = new Entity { IsIndication = false };
+
+            stringBuilder.AppendAccessControl(connectionInfo, entity);
+
+            var result = stringBuilder.ToString();
+
+            Assert.Equal(
+                $"Can Read: False{Environment.NewLine}" +
+                $"Can Create: False{Environment.NewLine}" +
+                $"Can Update: False{Environment.NewLine}" +
+                $"Can Delete: False{Environment.NewLine}",
+                result);
+        }
+
+
+        private static void TestAppendMethod(string input, string expected, Action<string, StringBuilder> funcToTest)
+        {
+            var stringBuilder = new StringBuilder();
+            funcToTest(input, stringBuilder);
+            var result = stringBuilder.ToString();
+            Assert.Equal(expected, result);
+        }
+
+    }
+}