diff --git a/src/EditorFeatures/Test/EditorServicesTest.csproj b/src/EditorFeatures/Test/EditorServicesTest.csproj
index 6152d08e9ed37..cb9d2bc1cd951 100644
--- a/src/EditorFeatures/Test/EditorServicesTest.csproj
+++ b/src/EditorFeatures/Test/EditorServicesTest.csproj
@@ -242,6 +242,7 @@
     <Compile Include="Diagnostics\GenerateType\TestProjectManagementService.cs" />
     <Compile Include="Diagnostics\SuppressMessageAttributeTests.cs" />
     <Compile Include="CodeFixes\ExtensionOrderingTests.cs" />
+    <Compile Include="Extensions\SourceTextContainerExtensionsTests.cs" />
     <Compile Include="Preview\TestOnly_CompilerDiagnosticAnalyzerProviderService.cs" />
     <Compile Include="DocCommentFormatting\DocCommentFormattingTests.cs" />
     <Compile Include="DocumentationComments\AbstractDocumentationCommentTests.cs" />
diff --git a/src/EditorFeatures/Test/Extensions/SourceTextContainerExtensionsTests.cs b/src/EditorFeatures/Test/Extensions/SourceTextContainerExtensionsTests.cs
new file mode 100644
index 0000000000000..c15d34d83d079
--- /dev/null
+++ b/src/EditorFeatures/Test/Extensions/SourceTextContainerExtensionsTests.cs
@@ -0,0 +1,34 @@
+using Microsoft.CodeAnalysis.Text;
+using Moq;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using Xunit;
+
+namespace Microsoft.CodeAnalysis.Editor.UnitTests.Extensions
+{
+    public class SourceTextContainerExtensionsTests
+    {
+        [Fact]
+        public void GetBufferTextFromNonTextContainerThrows()
+        {
+            var containerMock = new Mock<SourceTextContainer>();
+            Assert.Throws<ArgumentException>(() => Microsoft.CodeAnalysis.Text.Extensions.GetTextBuffer(containerMock.Object));
+        }
+
+        [Fact]
+        public void GetBufferTextFromTextContainerDoesNotThrow()
+        {
+            var textSnapshotMock = new Mock<VisualStudio.Text.ITextSnapshot>();
+            var bufferMock = new Mock<VisualStudio.Text.ITextBuffer>();
+            bufferMock.SetupGet(x => x.CurrentSnapshot).Returns(textSnapshotMock.Object);
+            bufferMock.SetupGet(x => x.Properties).Returns(new VisualStudio.Utilities.PropertyCollection());
+
+            var textContainer = Microsoft.CodeAnalysis.Text.Extensions.TextBufferContainer.From(bufferMock.Object);
+
+            Assert.DoesNotThrow(()=> Microsoft.CodeAnalysis.Text.Extensions.GetTextBuffer(textContainer));
+        }
+    }
+}
diff --git a/src/EditorFeatures/Text/Extensions.cs b/src/EditorFeatures/Text/Extensions.cs
index 6de7380cfb3ba..91b0b038bf9e8 100644
--- a/src/EditorFeatures/Text/Extensions.cs
+++ b/src/EditorFeatures/Text/Extensions.cs
@@ -25,7 +25,7 @@ public static ITextBuffer GetTextBuffer(this SourceTextContainer textContainer)
             var textBuffer = TryGetTextBuffer(textContainer);
             if (textBuffer == null)
             {
-                throw new ArgumentException(TextEditorResources.TextcontainerIsNotAnSource, "textContainer");
+                throw new ArgumentException(TextEditorResources.TextContainerNotFromTextBuffer, nameof(textContainer));
             }
 
             return textBuffer;
diff --git a/src/EditorFeatures/Text/TextEditorResources.Designer.cs b/src/EditorFeatures/Text/TextEditorResources.Designer.cs
index d4e95957d2146..dcd1d20ebc1f0 100644
--- a/src/EditorFeatures/Text/TextEditorResources.Designer.cs
+++ b/src/EditorFeatures/Text/TextEditorResources.Designer.cs
@@ -1,7 +1,7 @@
 //------------------------------------------------------------------------------
 // <auto-generated>
 //     This code was generated by a tool.
-//     Runtime Version:4.0.30319.18210
+//     Runtime Version:4.0.30319.0
 //
 //     Changes to this file may cause incorrect behavior and will be lost if
 //     the code is regenerated.
@@ -61,20 +61,11 @@ internal TextEditorResources() {
         }
         
         /// <summary>
-        ///   Looks up a localized string similar to textContainer is not an SourceTextContainer that was created from an ITextBuffer..
+        ///   Looks up a localized string similar to textContainer is not a SourceTextContainer that was created from an ITextBuffer..
         /// </summary>
-        internal static string TextcontainerIsNotAnSource {
+        internal static string TextContainerNotFromTextBuffer {
             get {
-                return ResourceManager.GetString("TextcontainerIsNotAnSource", resourceCulture);
-            }
-        }
-        
-        /// <summary>
-        ///   Looks up a localized string similar to text is not an SourceText that was created from an ITextSnapshot..
-        /// </summary>
-        internal static string TextIsNotAnSourcetextThat {
-            get {
-                return ResourceManager.GetString("TextIsNotAnSourcetextThat", resourceCulture);
+                return ResourceManager.GetString("TextContainerNotFromTextBuffer", resourceCulture);
             }
         }
     }
diff --git a/src/EditorFeatures/Text/TextEditorResources.resx b/src/EditorFeatures/Text/TextEditorResources.resx
index f82e3eee34ead..4fc852044cc74 100644
--- a/src/EditorFeatures/Text/TextEditorResources.resx
+++ b/src/EditorFeatures/Text/TextEditorResources.resx
@@ -117,10 +117,7 @@
   <resheader name="writer">
     <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
   </resheader>
-  <data name="TextcontainerIsNotAnSource" xml:space="preserve">
-    <value>textContainer is not an SourceTextContainer that was created from an ITextBuffer.</value>
-  </data>
-  <data name="TextIsNotAnSourcetextThat" xml:space="preserve">
-    <value>text is not an SourceText that was created from an ITextSnapshot.</value>
+  <data name="TextContainerNotFromTextBuffer" xml:space="preserve">
+    <value>textContainer is not a SourceTextContainer that was created from an ITextBuffer.</value>
   </data>
 </root>
\ No newline at end of file