Add StringBuilder.AppendJoin

Fix #24

Meziantou.Polyfill.Editor/M;System.Text.StringBuilder.AppendJoin(System.Char,System.Object[]).cs

@@ -0,0 +1,21 @@
+using System.Text;
+
+static partial class PolyfillExtensions
+{
+    public static StringBuilder AppendJoin(this StringBuilder target, char separator, params object?[] values)
+    {
+        var first = true;
+        foreach (var value in values)
+        {
+            if (!first)
+            {
+                target.Append(separator);
+            }
+
+            target.Append(value);
+            first = false;
+        }
+
+        return target;
+    }
+}

Meziantou.Polyfill.Editor/M;System.Text.StringBuilder.AppendJoin(System.Char,System.String[]).cs

@@ -0,0 +1,21 @@
+using System.Text;
+
+static partial class PolyfillExtensions
+{
+    public static StringBuilder AppendJoin(this StringBuilder target, char separator, params string?[] values)
+    {
+        var first = true;
+        foreach (var value in values)
+        {
+            if (!first)
+            {
+                target.Append(separator);
+            }
+
+            target.Append(value);
+            first = false;
+        }
+
+        return target;
+    }
+}

Meziantou.Polyfill.Editor/M;System.Text.StringBuilder.AppendJoin(System.String,System.Object[]).cs

@@ -0,0 +1,21 @@
+using System.Text;
+
+static partial class PolyfillExtensions
+{
+    public static StringBuilder AppendJoin(this StringBuilder target, string? separator, params object?[] values)
+    {
+        var first = true;
+        foreach (var value in values)
+        {
+            if (!first)
+            {
+                target.Append(separator);
+            }
+
+            target.Append(value);
+            first = false;
+        }
+
+        return target;
+    }
+}

Meziantou.Polyfill.Editor/M;System.Text.StringBuilder.AppendJoin(System.String,System.String[]).cs

@@ -0,0 +1,21 @@
+using System.Text;
+
+static partial class PolyfillExtensions
+{
+    public static StringBuilder AppendJoin(this StringBuilder target, string? separator, params string?[] values)
+    {
+        var first = true;
+        foreach (var value in values)
+        {
+            if (!first)
+            {
+                target.Append(separator);
+            }
+
+            target.Append(value);
+            first = false;
+        }
+
+        return target;
+    }
+}

Meziantou.Polyfill.Editor/M;System.Text.StringBuilder.AppendJoin``1(System.Char,System.Collections.Generic.IEnumerable{``0}).cs

@@ -0,0 +1,22 @@
+using System.Collections.Generic;
+using System.Text;
+
+static partial class PolyfillExtensions
+{
+    public static StringBuilder AppendJoin<T>(this StringBuilder target, char separator, IEnumerable<T> values)
+    {
+        var first = true;
+        foreach (var value in values)
+        {
+            if (!first)
+            {
+                target.Append(separator);
+            }
+
+            target.Append(value);
+            first = false;
+        }
+
+        return target;
+    }
+}

Meziantou.Polyfill.Editor/M;System.Text.StringBuilder.AppendJoin``1(System.String,System.Collections.Generic.IEnumerable{``0}).cs

@@ -0,0 +1,22 @@
+using System.Collections.Generic;
+using System.Text;
+
+static partial class PolyfillExtensions
+{
+    public static StringBuilder AppendJoin<T>(this StringBuilder target, string? separator, IEnumerable<T> values)
+    {
+        var first = true;
+        foreach (var value in values)
+        {
+            if (!first)
+            {
+                target.Append(separator);
+            }
+
+            target.Append(value);
+            first = false;
+        }
+
+        return target;
+    }
+}

Meziantou.Polyfill.Generator/Program.cs

@@ -22,6 +22,8 @@
                                .Replace('}', '_')
                                .Replace('(', '_')
                                .Replace(')', '_')
+                               .Replace('[', '_')
+                               .Replace(']', '_')
                                .Replace(',', '_')
                                .Replace('.', '_')
                                .Replace('`', '_'),
@@ -193,6 +195,7 @@ string GenerateIncludePostCondition(PolyfillData data)
 sb.AppendLine("}");
 
 Console.WriteLine(sb.ToString());
+Console.WriteLine("Polyfills: " + polyfills.Length);
 var path = GetMemberFilePath();
 Console.WriteLine(path);
 File.WriteAllText(path, sb.ToString());

Meziantou.Polyfill.Tests/UnitTest1.cs

@@ -457,4 +457,66 @@ public void Encoding_GetString()
         var str = Encoding.UTF8.GetString((ReadOnlySpan<byte>)Encoding.UTF8.GetBytes("sample").AsSpan());
         Assert.Equal("sample", str);
     }
+
+    [Fact]
+    public void StringBuilder_AppendJoin_String_ObjectArray()
+    {
+        var sb = new StringBuilder();
+        sb.AppendJoin(", ", 1, 2, 3);
+        Assert.Equal("1, 2, 3", sb.ToString());
+    }
+
+    [Fact]
+    public void StringBuilder_AppendJoin_String_StringArray()
+    {
+        var sb = new StringBuilder();
+        sb.AppendJoin(", ", "1", "2", "3");
+        Assert.Equal("1, 2, 3", sb.ToString());
+    }
+
+    [Fact]
+    public void StringBuilder_AppendJoin_String_IEnumerable()
+    {
+        var sb = new StringBuilder();
+        sb.AppendJoin(", ", Enumerable());
+        Assert.Equal("1, 2, 3", sb.ToString());
+
+        static IEnumerable<string> Enumerable()
+        {
+            yield return "1";
+            yield return "2";
+            yield return "3";
+        }
+    }
+
+    [Fact]
+    public void StringBuilder_AppendJoin_Char_ObjectArray()
+    {
+        var sb = new StringBuilder();
+        sb.AppendJoin(',', 1, 2, 3);
+        Assert.Equal("1,2,3", sb.ToString());
+    }
+
+    [Fact]
+    public void StringBuilder_AppendJoin_Char_StringArray()
+    {
+        var sb = new StringBuilder();
+        sb.AppendJoin(',', "1", "2", "3");
+        Assert.Equal("1,2,3", sb.ToString());
+    }
+
+    [Fact]
+    public void StringBuilder_AppendJoin_Char_IEnumerable()
+    {
+        var sb = new StringBuilder();
+        sb.AppendJoin(',', Enumerable());
+        Assert.Equal("1,2,3", sb.ToString());
+
+        static IEnumerable<string> Enumerable()
+        {
+            yield return "1";
+            yield return "2";
+            yield return "3";
+        }
+    }
 }

Meziantou.Polyfill/Meziantou.Polyfill.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <TargetFrameworks>netstandard2.0</TargetFrameworks>
-    <Version>1.0.25</Version>
+    <Version>1.0.26</Version>
     <TransformOnBuild>true</TransformOnBuild>
 
     <LangVersion>11</LangVersion>