From 5275aa72fb893d197d2b02d0e2b8efa6b074db8b Mon Sep 17 00:00:00 2001
From: Mark McDowall <mark@mcdowall.ca>
Date: Mon, 10 Jun 2019 21:32:09 -0700
Subject: [PATCH] Clean up FirstCharacterToLower extension + tests

---
 ...rFixture.cs => FirstCharacterToLowerFixture.cs} |  4 +++-
 .../FirstCharcacterToUpperFixture.cs               |  2 ++
 .../NzbDrone.Common.Test.csproj                    |  2 +-
 src/NzbDrone.Common/Extensions/StringExtensions.cs | 14 ++++++++++++--
 4 files changed, 18 insertions(+), 4 deletions(-)
 rename src/NzbDrone.Common.Test/ExtensionTests/StringExtensionTests/{FirstCharcacterToLowerFixture.cs => FirstCharacterToLowerFixture.cs} (82%)

diff --git a/src/NzbDrone.Common.Test/ExtensionTests/StringExtensionTests/FirstCharcacterToLowerFixture.cs b/src/NzbDrone.Common.Test/ExtensionTests/StringExtensionTests/FirstCharacterToLowerFixture.cs
similarity index 82%
rename from src/NzbDrone.Common.Test/ExtensionTests/StringExtensionTests/FirstCharcacterToLowerFixture.cs
rename to src/NzbDrone.Common.Test/ExtensionTests/StringExtensionTests/FirstCharacterToLowerFixture.cs
index e1314dcca..901668734 100644
--- a/src/NzbDrone.Common.Test/ExtensionTests/StringExtensionTests/FirstCharcacterToLowerFixture.cs
+++ b/src/NzbDrone.Common.Test/ExtensionTests/StringExtensionTests/FirstCharacterToLowerFixture.cs
@@ -5,11 +5,13 @@ using NzbDrone.Common.Extensions;
 namespace NzbDrone.Common.Test.ExtensionTests.StringExtensionTests
 {
     [TestFixture]
-    public class FirstCharcacterToLowerFixture
+    public class FirstCharacterToLowerFixture
     {
         [TestCase("Hello", "hello")]
         [TestCase("CamelCase", "camelCase")]
         [TestCase("A Full Sentence", "a Full Sentence")]
+        [TestCase("", "")]
+        [TestCase(null, "")]
         public void should_lower_case_first_character(string input, string expected)
         {
             input.FirstCharToLower().Should().Be(expected);
diff --git a/src/NzbDrone.Common.Test/ExtensionTests/StringExtensionTests/FirstCharcacterToUpperFixture.cs b/src/NzbDrone.Common.Test/ExtensionTests/StringExtensionTests/FirstCharcacterToUpperFixture.cs
index bf8169b60..53e221f4e 100644
--- a/src/NzbDrone.Common.Test/ExtensionTests/StringExtensionTests/FirstCharcacterToUpperFixture.cs
+++ b/src/NzbDrone.Common.Test/ExtensionTests/StringExtensionTests/FirstCharcacterToUpperFixture.cs
@@ -10,6 +10,8 @@ namespace NzbDrone.Common.Test.ExtensionTests.StringExtensionTests
         [TestCase("hello", "Hello")]
         [TestCase("camelCase", "CamelCase")]
         [TestCase("a full sentence", "A full sentence")]
+        [TestCase("", "")]
+        [TestCase(null, "")]
         public void should_capitalize_first_character(string input, string expected)
         {
             input.FirstCharToUpper().Should().Be(expected);
diff --git a/src/NzbDrone.Common.Test/NzbDrone.Common.Test.csproj b/src/NzbDrone.Common.Test/NzbDrone.Common.Test.csproj
index 9f547171e..7d28931b1 100644
--- a/src/NzbDrone.Common.Test/NzbDrone.Common.Test.csproj
+++ b/src/NzbDrone.Common.Test/NzbDrone.Common.Test.csproj
@@ -85,7 +85,7 @@
     <Compile Include="ExtensionTests\IEnumerableExtensionTests\IntersectByFixture.cs" />
     <Compile Include="ExtensionTests\Int64ExtensionFixture.cs" />
     <Compile Include="ExtensionTests\IPAddressExtensionsFixture.cs" />
-    <Compile Include="ExtensionTests\StringExtensionTests\FirstCharcacterToLowerFixture.cs" />
+    <Compile Include="ExtensionTests\StringExtensionTests\FirstCharacterToLowerFixture.cs" />
     <Compile Include="ExtensionTests\StringExtensionTests\FirstCharcacterToUpperFixture.cs" />
     <Compile Include="ExtensionTests\UrlExtensionsFixture.cs" />
     <Compile Include="HashUtilFixture.cs" />
diff --git a/src/NzbDrone.Common/Extensions/StringExtensions.cs b/src/NzbDrone.Common/Extensions/StringExtensions.cs
index 3de53ef0d..b7d058657 100644
--- a/src/NzbDrone.Common/Extensions/StringExtensions.cs
+++ b/src/NzbDrone.Common/Extensions/StringExtensions.cs
@@ -24,12 +24,22 @@ namespace NzbDrone.Common.Extensions
 
         public static string FirstCharToLower(this string input)
         {
-            return input.First().ToString().ToLower() + input.Substring(1);
+            if (string.IsNullOrEmpty(input))
+            {
+                return string.Empty;
+            }
+
+            return char.ToLowerInvariant(input.First()) + input.Substring(1);
         }
 
         public static string FirstCharToUpper(this string input)
         {
-            return input.First().ToString().ToUpper() + input.Substring(1);
+            if (string.IsNullOrEmpty(input))
+            {
+                return string.Empty;
+            }
+
+            return char.ToUpperInvariant(input.First()) + input.Substring(1);
         }
 
         public static string Inject(this string format, params object[] formattingArgs)