Some collection and string helper functions

CsharpUtils/CollectionHelper.cs

@@ -55,5 +55,10 @@ public static bool EquivalentTo<T>(this List<T> left, List<T> right)
       }
       return true;
     }
+
+    public static bool IsNullOrEmpty<T>(this List<T> list)
+    {
+      return list == null || list.Count == 0;
+    }
   }
 }

CsharpUtils/StringHelper.cs

@@ -1,10 +1,40 @@
-namespace CsharpUtils
+using System;
+using System.Linq;
+
+namespace CsharpUtils
 {
   public static class StringHelper
   {
+    #region Truncate
+
     public static string TruncateLastChars(this string source, int number)
     {
       return source.Substring(0, source.Length - number);
     }
+
+    public static string TruncateLastChar(this string source)
+    {
+      return source.TruncateLastChars(1);
+    }
+
+    public static string TruncateEnding(this string source, string ending)
+    {
+      if (!source.EndsWith(ending))
+      {
+        throw new InvalidOperationException(string.Format("'{0}' does not end with '{1}'", source, ending));
+      }
+      return source.TruncateLastChars(ending.Length);
+    }
+
+    #endregion
+
+    #region Ends with
+
+    public static bool EndsWithOneOf(this string source, params string[] endings)
+    {
+      return endings.Any(source.EndsWith);
+    }
+
+    #endregion
   }
 }

CsharpUtilsTest/CollectionHelperTest.cs

@@ -95,5 +95,27 @@ public void IsEquivalentWorksWhenEquivalent()
     }
 
     #endregion
+
+    #region IsNullOrEmpty
+
+    [TestMethod]
+    public void IsNullOrEmptyWorksForNull()
+    {
+      Assert.IsTrue((null as List<string>).IsNullOrEmpty());
+    }
+
+    [TestMethod]
+    public void IsNullOrEmptyWorksForEmpty()
+    {
+      Assert.IsTrue(new List<string>().IsNullOrEmpty());
+    }
+
+    [TestMethod]
+    public void IsNullOrEmptyWorksForFullList()
+    {
+      Assert.IsFalse(new List<string>{"hello", "goodbye"}.IsNullOrEmpty());
+    }
+
+    #endregion
   }
 }

CsharpUtilsTest/StringHelperTest.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 using CsharpUtils;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
 
@@ -7,6 +8,8 @@ namespace CsharpUtilsTest
   [TestClass]
   public class StringHelperTest
   {
+    #region Truncate last chars
+
     [TestMethod]
     public void TruncateLastCharsWorks()
     {
@@ -19,5 +22,51 @@ public void TruncateLastThrowsWhenNumberOfCharsExceedsLength()
     {
       "hell".TruncateLastChars(50);
     }
+
+    [TestMethod]
+    public void TruncateLastCharWorks()
+    {
+      var test = new List<string> {"a", "ab", "abcde"};
+      test.ForEach(s => Assert.AreEqual(s.TruncateLastChars(1), s.TruncateLastChar()));
+    }
+
+    [TestMethod]
+    public void TruncateEndingWorks()
+    {
+      Assert.AreEqual("SomeRandomString", "SomeRandomStringWithEnding".TruncateEnding("WithEnding"));
+    }
+
+    [TestMethod]
+    [ExpectedException(typeof(InvalidOperationException))]
+    public void TruncateEndingThrowsWhenSourceDoesNotHaveEnding()
+    {
+      "SomeRandomString".TruncateEnding("TheEnding");
+    }
+
+    #endregion
+
+    #region Ends with
+
+    [TestMethod]
+    public void EndsWithOneOfWorksWithNoArgs()
+    {
+      Assert.IsFalse("blah".EndsWithOneOf());
+    }
+
+    [TestMethod]
+    public void EndsWithOneOfWorksWithOneArg()
+    {
+      Assert.IsTrue("blahDeBlah".EndsWithOneOf("Blah"));
+      Assert.IsFalse("blahDeBlah".EndsWithOneOf("blah"));
+    }
+
+    [TestMethod]
+    public void EndsWithOneOfWorksWithMultipleArgs()
+    {
+      Assert.IsTrue("amo".EndsWithOneOf("o", "a"));
+      Assert.IsFalse("amor".EndsWithOneOf("o", "a"));
+    }
+
+    #endregion
   }
 }