[PreviewPane][Monaco]Format json/xml before rendering (#19980)

src/modules/previewpane/MonacoPreviewHandler/Formatters/IFormatter.cs

@@ -0,0 +1,21 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+namespace Microsoft.PowerToys.PreviewHandler.Monaco.Formatters
+{
+    public interface IFormatter
+    {
+        /// <summary>
+        /// Gets the language to which the formatter is applied
+        /// </summary>
+        string LangSet { get; }
+
+        /// <summary>
+        /// Format the value
+        /// </summary>
+        /// <param name="value">The value to format</param>
+        /// <returns>The value formatted</returns>
+        string Format(string value);
+    }
+}

src/modules/previewpane/MonacoPreviewHandler/Formatters/JsonFormatter.cs

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+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+namespace Microsoft.PowerToys.PreviewHandler.Monaco.Formatters
+{
+    using System.Text.Json;
+
+    public class JsonFormatter : IFormatter
+    {
+        /// <inheritdoc/>
+        public string LangSet => "json";
+
+        /// <inheritdoc/>
+        public string Format(string value)
+        {
+            if (string.IsNullOrWhiteSpace(value))
+            {
+                return string.Empty;
+            }
+
+            using (var jDocument = JsonDocument.Parse(value, new JsonDocumentOptions { CommentHandling = JsonCommentHandling.Skip }))
+            {
+                return JsonSerializer.Serialize(jDocument, new JsonSerializerOptions { WriteIndented = true });
+            }
+        }
+    }
+}

src/modules/previewpane/MonacoPreviewHandler/Formatters/XmlFormatter.cs

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+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+namespace Microsoft.PowerToys.PreviewHandler.Monaco.Formatters
+{
+    using System.Text;
+    using System.Xml;
+
+    public class XmlFormatter : IFormatter
+    {
+        /// <inheritdoc/>
+        public string LangSet => "xml";
+
+        /// <inheritdoc/>
+        public string Format(string value)
+        {
+            if (string.IsNullOrWhiteSpace(value))
+            {
+                return string.Empty;
+            }
+
+            var xmlDocument = new XmlDocument();
+            xmlDocument.LoadXml(value);
+
+            var stringBuilder = new StringBuilder();
+            var xmlWriterSettings = new XmlWriterSettings()
+            {
+                OmitXmlDeclaration = xmlDocument.FirstChild.NodeType != XmlNodeType.XmlDeclaration,
+                Indent = true,
+            };
+
+            using (var xmlWriter = XmlWriter.Create(stringBuilder, xmlWriterSettings))
+            {
+                xmlDocument.Save(xmlWriter);
+            }
+
+            return stringBuilder.ToString();
+        }
+    }
+}