Testing and more assertions.

Author: Oren (electricessence)

Source/.editorconfig

@@ -0,0 +1,7 @@
+[*.cs]
+
+# CA1303: Do not pass literals as localized parameters
+dotnet_diagnostic.CA1303.severity = silent
+
+# CA1707: Identifiers should not contain underscores
+dotnet_diagnostic.CA1707.severity = silent

Open.Text.csproj Source/Open.Text.csprojOpen.Text.csproj renamed to Source/Open.Text.csproj

@@ -15,7 +15,7 @@ Part of the "Open" set of libraries.
 		<RepositoryUrl>https://github.com/Open-NET-Libraries/Open.Text</RepositoryUrl>
 		<RepositoryType>git</RepositoryType>
 		<PackageTags>dotnet, dotnetcore, string, text, format, stringbuilder, extensions</PackageTags>
-    <Version>2.2.0</Version>
+    <Version>2.3.0</Version>
     <PackageReleaseNotes></PackageReleaseNotes>
 		<PackageLicenseExpression>MIT</PackageLicenseExpression>
 		<PublishRepositoryUrl>true</PublishRepositoryUrl>
@@ -29,8 +29,10 @@ Part of the "Open" set of libraries.
 	</ItemGroup>
 
   <ItemGroup>
+    <None Remove=".editorconfig" />
     <None Remove=".git" />
     <None Remove=".gitignore" />
+    <AdditionalFiles Include=".editorconfig" />
     <None Include="logo.png">
       <Pack>True</Pack>
       <PackagePath></PackagePath>
@@ -39,6 +41,10 @@ Part of the "Open" set of libraries.
 
   <ItemGroup>
     <PackageReference Include="Open.MemoryExtensions" Version="2.7.0" />
-  </ItemGroup>
+		<PackageReference Include="Microsoft.CodeAnalysis.FxCopAnalyzers" Version="3.0.0">
+			<PrivateAssets>all</PrivateAssets>
+			<IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+		</PackageReference>
+	</ItemGroup>
 
 </Project>

StringBuilderExtensions.cs Source/StringBuilderExtensions.csStringBuilderExtensions.cs renamed to Source/StringBuilderExtensions.cs

@@ -1,4 +1,9 @@
-using System;
+/*!
+ * @author electricessence / https://github.com/electricessence/
+ * Licensing: MIT
+ */
+
+using System;
 using System.Collections.Generic;
 using System.Diagnostics.Contracts;
 using System.Text;
@@ -7,6 +12,14 @@ namespace Open.Text
 {
 	public static class StringBuilderExtensions
 	{
+		private const string ParametersMissing = "Parameters missing.";
+
+		/// <summary>
+		/// Adds every entry to a StringBuilder.
+		/// </summary>
+		/// <typeparam name="T">The type of the source.</typeparam>
+		/// <param name="source">The source span.</param>
+		/// <returns>The resultant StringBuilder.</returns>
 		public static StringBuilder ToStringBuilder<T>(this in ReadOnlySpan<T> source)
 		{
 			var len = source.Length;
@@ -18,15 +31,29 @@ public static StringBuilder ToStringBuilder<T>(this in ReadOnlySpan<T> source)
 			return sb;
 		}
 
+		/// <summary>
+		/// Adds every entry to a StringBuilder.
+		/// </summary>
+		/// <typeparam name="T">The type of the source.</typeparam>
+		/// <param name="source">The source span.</param>
+		/// <returns>The resultant StringBuilder.</returns>
 		public static StringBuilder ToStringBuilder<T>(this IEnumerable<T> source)
 		{
+			if (source is null) throw new NullReferenceException();
 			var sb = new StringBuilder();
 			foreach (var s in source)
 				sb.Append(s);
 
 			return sb;
 		}
 
+		/// <summary>
+		/// Adds every entry to a StringBuilder separated by the specified sequence.
+		/// </summary>
+		/// <typeparam name="T">The type of the source.</typeparam>
+		/// <param name="source">The source span.</param>
+		/// <param name="separator">The separator sequence.</param>
+		/// <returns>The resultant StringBuilder.</returns>
 		public static StringBuilder ToStringBuilder<T>(this in ReadOnlySpan<T> source, string separator)
 		{
 			var len = source.Length;
@@ -45,11 +72,17 @@ public static StringBuilder ToStringBuilder<T>(this in ReadOnlySpan<T> source, s
 			return sb;
 		}
 
+		/// <summary>
+		/// Adds every entry to a StringBuilder separated by the specified character.
+		/// </summary>
+		/// <typeparam name="T">The type of the source.</typeparam>
+		/// <param name="source">The source span.</param>
+		/// <param name="separator">The separator character.</param>
+		/// <returns>The resultant StringBuilder.</returns>
 		public static StringBuilder ToStringBuilder<T>(this in ReadOnlySpan<T> source, in char separator)
 		{
 			var len = source.Length;
-			if (len < 2)
-				return ToStringBuilder(source);
+			if (len < 2) return ToStringBuilder(source);
 
 			var sb = new StringBuilder(2 * len - 1);
 
@@ -63,10 +96,23 @@ public static StringBuilder ToStringBuilder<T>(this in ReadOnlySpan<T> source, i
 			return sb;
 		}
 
+		/// <summary>
+		/// Adds every entry to a StringBuilder separated by the specified sequence.
+		/// </summary>
+		/// <typeparam name="T">The type of the source.</typeparam>
+		/// <param name="source">The source enumerable.</param>
+		/// <param name="separator">The separator sequence.</param>
+		/// <returns>The resultant StringBuilder.</returns>
 		public static StringBuilder ToStringBuilder<T>(this IEnumerable<T> source, string separator)
 		{
-			var sb = new StringBuilder();
+			if (source is null) throw new NullReferenceException();
+			Contract.EndContractBlock();
+
+			if (string.IsNullOrEmpty(separator))
+				return ToStringBuilder(source);
+
 			var first = true;
+			var sb = new StringBuilder();
 			foreach (var s in source)
 			{
 				if (first) first = false;
@@ -76,8 +122,18 @@ public static StringBuilder ToStringBuilder<T>(this IEnumerable<T> source, strin
 			return sb;
 		}
 
+		/// <summary>
+		/// Adds every entry to a StringBuilder separated by the specified character.
+		/// </summary>
+		/// <typeparam name="T">The type of the source.</typeparam>
+		/// <param name="source">The source enumerable.</param>
+		/// <param name="separator">The separator character.</param>
+		/// <returns>The resultant StringBuilder.</returns>
 		public static StringBuilder ToStringBuilder<T>(this IEnumerable<T> source, in char separator)
 		{
+			if (source is null) throw new NullReferenceException();
+			Contract.EndContractBlock();
+
 			var sb = new StringBuilder();
 			var first = true;
 			foreach (var s in source)
@@ -139,7 +195,7 @@ public static StringBuilder AppendWithSeparator<T>(this StringBuilder target, st
 			if (target is null)
 				throw new NullReferenceException();
 			if (values is null || values.Length == 0)
-				throw new ArgumentException("Parameters missing.");
+				throw new ArgumentException(ParametersMissing);
 			Contract.EndContractBlock();
 
 			if (!string.IsNullOrEmpty(separator) && target.Length != 0)
@@ -157,7 +213,7 @@ public static StringBuilder AppendWithSeparator<T>(this StringBuilder target, in
 			if (target is null)
 				throw new NullReferenceException();
 			if (values is null || values.Length == 0)
-				throw new ArgumentException("Parameters missing.");
+				throw new ArgumentException(ParametersMissing);
 			Contract.EndContractBlock();
 
 			if (target.Length != 0)