SplitString: fix platform-dependent newline split, retarget net10.0

strings-csharp/SplitString/SplitString/Program.cs

@@ -17,13 +17,22 @@ static void Main(string[] args)
             SplitStringUsingCharacterArrayWithoptionsUsingCount(" apple , banana ; cherry,orange ", new[] { ',', ';' }, 3);
 
             Console.WriteLine("\n***************** Split the String Using String Array with String Split Options ***************\n");
-            SplitStringUsingStringArrayWithoptions("apple,banana,kiwi;grape,mango,orange", new[] { ",", ";" });
+            SplitStringUsingStringArrayWithoptions("apple,,banana;;kiwi", new[] { ",", ";" }, StringSplitOptions.RemoveEmptyEntries);
 
             Console.WriteLine("\n***************** Split the String Using String Array with String Split Options Using Count ***************\n");
             SplitStringUsingStringArrayWithoptionsUsingCount("apple,banana,cherry,orange,pear", new[] { "," }, 3);
 
             Console.WriteLine("\n***************** Split a String Into New Lines ***************\n");
-            SplitStringIntoNewLines("Line 1\nLine 2\nLine 3\nLine 4\nLine 5", new[] { Environment.NewLine });
+            SplitStringIntoNewLines("Line 1\nLine 2\nLine 3\nLine 4\nLine 5", ["\r\n", "\n"]);
+
+            Console.WriteLine("\n***************** StringSplitOptions on the Same Input ***************\n");
+            SplitStringWithOptions("a,,b, c, , d ,e", ',', StringSplitOptions.None);
+            SplitStringWithOptions("a,,b, c, , d ,e", ',', StringSplitOptions.RemoveEmptyEntries);
+            SplitStringWithOptions("a,,b, c, , d ,e", ',', StringSplitOptions.TrimEntries);
+            SplitStringWithOptions("a,,b, c, , d ,e", ',', StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries);
+
+            Console.WriteLine("\n***************** Split a String Without Allocating Substrings ***************\n");
+            CountSplitRanges("apple,banana,cherry,date", ',');
         }
 
         public static string[] SplitStringUsingCharacterArray(string input, char[] separators)
@@ -73,9 +82,10 @@ public static string[] SplitStringUsingCharacterArrayWithoptionsUsingCount(strin
             return result;
         }
 
-        public static string[] SplitStringUsingStringArrayWithoptions(string input, string[] delimiters)
+        public static string[] SplitStringUsingStringArrayWithoptions(string input, string[] delimiters,
+            StringSplitOptions options = StringSplitOptions.None)
         {
-            string[] result = input.Split(delimiters, StringSplitOptions.None);
+            string[] result = input.Split(delimiters, options);
 
             foreach (string s in result)
             {
@@ -108,5 +118,29 @@ public static string[] SplitStringIntoNewLines(string multiLineText, string[] se
 
             return lines;
         }
+
+        public static string[] SplitStringWithOptions(string input, char separator, StringSplitOptions options)
+        {
+            string[] result = input.Split(separator, options);
+
+            Console.WriteLine($"{options}: [{string.Join("] [", result)}]");
+
+            return result;
+        }
+
+        public static int CountSplitRanges(string input, char separator)
+        {
+            ReadOnlySpan<char> source = input;
+            Span<Range> ranges = stackalloc Range[8];
+
+            int count = source.Split(ranges, separator);
+
+            for (int i = 0; i < count; i++)
+            {
+                Console.WriteLine(source[ranges[i]].ToString());
+            }
+
+            return count;
+        }
     }
 }

strings-csharp/SplitString/SplitString/SplitString.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFramework>net10.0</TargetFramework>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
   </PropertyGroup>

strings-csharp/SplitString/SplitStringTests/SplitStringTests.cs

@@ -104,14 +104,100 @@ public void WhenSplittingAStringIntoNewLine_ThenReturnArrayOfSubstrings()
         {
             // Arrange
             string input = "Line 1\nLine 2\nLine 3\nLine 4\nLine 5";
-            string[] separators = { Environment.NewLine };
-            int expectedOutputLength = 5;
+            string[] separators = ["\r\n", "\n"];
+            string[] expectedOutput = ["Line 1", "Line 2", "Line 3", "Line 4", "Line 5"];
 
             // Act
             string[] result = Program.SplitStringIntoNewLines(input, separators);
 
             // Assert
-            Assert.AreEqual(expectedOutputLength, result.Length);
+            CollectionAssert.AreEqual(expectedOutput, result);
+        }
+
+        [TestMethod]
+        public void WhenSplittingCrLfAndLfMixedText_ThenReturnOneEntryPerLineOnEveryPlatform()
+        {
+            // Arrange
+            string input = "Line 1\r\nLine 2\nLine 3\r\nLine 4";
+            string[] separators = ["\r\n", "\n"];
+            string[] expectedOutput = ["Line 1", "Line 2", "Line 3", "Line 4"];
+
+            // Act
+            string[] result = Program.SplitStringIntoNewLines(input, separators);
+
+            // Assert
+            CollectionAssert.AreEqual(expectedOutput, result);
+        }
+
+        [TestMethod]
+        public void WhenSplittingWithNone_ThenKeepEveryPieceAsCut()
+        {
+            // Arrange
+            string input = "a,,b, c, , d ,e";
+            string[] expectedOutput = ["a", "", "b", " c", " ", " d ", "e"];
+
+            // Act
+            string[] result = Program.SplitStringWithOptions(input, ',', StringSplitOptions.None);
+
+            // Assert
+            CollectionAssert.AreEqual(expectedOutput, result);
+        }
+
+        [TestMethod]
+        public void WhenSplittingWithRemoveEmptyEntries_ThenDropZeroLengthPiecesOnly()
+        {
+            // Arrange
+            string input = "a,,b, c, , d ,e";
+            string[] expectedOutput = ["a", "b", " c", " ", " d ", "e"];
+
+            // Act
+            string[] result = Program.SplitStringWithOptions(input, ',', StringSplitOptions.RemoveEmptyEntries);
+
+            // Assert
+            CollectionAssert.AreEqual(expectedOutput, result);
+        }
+
+        [TestMethod]
+        public void WhenSplittingWithTrimEntries_ThenTrimEveryPieceAndKeepTheEmpties()
+        {
+            // Arrange
+            string input = "a,,b, c, , d ,e";
+            string[] expectedOutput = ["a", "", "b", "c", "", "d", "e"];
+
+            // Act
+            string[] result = Program.SplitStringWithOptions(input, ',', StringSplitOptions.TrimEntries);
+
+            // Assert
+            CollectionAssert.AreEqual(expectedOutput, result);
+        }
+
+        [TestMethod]
+        public void WhenSplittingWithRemoveEmptyEntriesAndTrimEntries_ThenTrimFirstThenDrop()
+        {
+            // Arrange
+            string input = "a,,b, c, , d ,e";
+            string[] expectedOutput = ["a", "b", "c", "d", "e"];
+
+            // Act
+            string[] result = Program.SplitStringWithOptions(input, ',',
+                StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries);
+
+            // Assert
+            CollectionAssert.AreEqual(expectedOutput, result);
+        }
+
+        [TestMethod]
+        public void WhenSplittingIntoRanges_ThenReturnThePieceCountWithoutAllocatingSubstrings()
+        {
+            // Arrange
+            string input = "apple,banana,cherry,date";
+            int expectedCount = 4;
+
+            // Act
+            int count = Program.CountSplitRanges(input, ',');
+
+            // Assert
+            Assert.AreEqual(expectedCount, count);
         }
     }
 }

strings-csharp/SplitString/SplitStringTests/SplitStringTests.csproj

@@ -1,18 +1,18 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFramework>net10.0</TargetFramework>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
 
     <IsPackable>false</IsPackable>
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.1.0" />
-    <PackageReference Include="MSTest.TestAdapter" Version="2.2.8" />
-    <PackageReference Include="MSTest.TestFramework" Version="2.2.8" />
-    <PackageReference Include="coverlet.collector" Version="3.1.2" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.9.0" />
+    <PackageReference Include="MSTest.TestAdapter" Version="4.3.3" />
+    <PackageReference Include="MSTest.TestFramework" Version="4.3.3" />
+    <PackageReference Include="coverlet.collector" Version="10.0.1" />
   </ItemGroup>
 
   <ItemGroup>