Add SDLPrinter synchronous extension methods (#277)

Author: Shane32

src/GraphQLParser.ApiTests/GraphQLParser.approved.txt

@@ -884,6 +884,12 @@ namespace GraphQLParser.Visitors
             public System.IO.TextWriter Writer { get; }
         }
     }
+    public static class SDLPrinterExtensions
+    {
+        public static string Print(this GraphQLParser.Visitors.SDLPrinter printer, GraphQLParser.AST.ASTNode node) { }
+        public static void Print(this GraphQLParser.Visitors.SDLPrinter printer, GraphQLParser.AST.ASTNode node, System.Text.StringBuilder stringBuilder) { }
+        public static void Print(this GraphQLParser.Visitors.SDLPrinter printer, GraphQLParser.AST.ASTNode node, System.IO.MemoryStream memoryStream, System.Text.Encoding? encoding = null) { }
+    }
     public class SDLPrinterOptions
     {
         public SDLPrinterOptions() { }

src/GraphQLParser.Tests/Visitors/SDLPrinterTests.cs

@@ -5,6 +5,35 @@ namespace GraphQLParser.Tests.Visitors;
 
 public class SDLPrinterTests
 {
+    [Fact]
+    public async Task Print_Matches_PrintAsync_String()
+    {
+        var query = "KitchenSink".ReadGraphQLFile().Parse();
+        var writer = new SDLPrinter();
+        var sw = new StringWriter();
+        await writer.PrintAsync(query, sw);
+        sw.Flush();
+        var txt = sw.ToString();
+        writer.Print(query).ShouldBe(txt);
+    }
+
+    [Fact]
+    public async Task Print_Matches_PrintAsync_Bytes()
+    {
+        var query = "KitchenSink".ReadGraphQLFile().Parse();
+        var writer = new SDLPrinter();
+        var ms1 = new MemoryStream();
+        var sw = new StreamWriter(ms1);
+        await writer.PrintAsync(query, sw);
+        sw.Flush();
+
+        var ms2 = new MemoryStream();
+        writer.Print(query, ms2);
+        var bytes1 = ms1.ToArray();
+        var bytes2 = ms2.ToArray();
+        bytes1.ShouldBe(bytes2);
+    }
+
     [Fact]
     public void SDLPrinter_Should_Have_Default_Options()
     {

src/GraphQLParser/Visitors/SDLPrinterExtensions.cs

@@ -0,0 +1,42 @@
+using System.Text;
+using GraphQLParser.AST;
+
+namespace GraphQLParser.Visitors;
+
+/// <summary>
+/// Extension methods for <see cref="SDLPrinter"/>.
+/// </summary>
+public static class SDLPrinterExtensions
+{
+    /// <summary>
+    /// Returns the specified AST printed as a SDL document.
+    /// </summary>
+    public static string Print(this SDLPrinter printer, ASTNode node)
+    {
+        var sb = new StringBuilder();
+        printer.Print(node, sb);
+        return sb.ToString();
+    }
+
+    /// <summary>
+    /// Prints the specified AST into the specified <see cref="StringBuilder"/> as a SDL document.
+    /// </summary>
+    public static void Print(this SDLPrinter printer, ASTNode node, StringBuilder stringBuilder)
+#pragma warning disable CA2012 // Use ValueTasks correctly
+        => printer.PrintAsync(node, new StringWriter(stringBuilder), default).GetAwaiter().GetResult();
+#pragma warning restore CA2012 // Use ValueTasks correctly
+
+    /// <summary>
+    /// Prints the specified AST into the specified <see cref="MemoryStream"/> as a SDL document.
+    /// If no encoding is specified, the document is written in UTF-8 format without a byte order mark.
+    /// </summary>
+    public static void Print(this SDLPrinter printer, ASTNode node, MemoryStream memoryStream, Encoding? encoding = null)
+    {
+        using var streamWriter = new StreamWriter(memoryStream, encoding, -1 /* default */, true);
+#pragma warning disable CA2012 // Use ValueTasks correctly
+        printer.PrintAsync(node, streamWriter, default).GetAwaiter().GetResult();
+#pragma warning restore CA2012 // Use ValueTasks correctly
+        // flush encoder state to stream
+        streamWriter.Flush();
+    }
+}