🧆 Use source generation for Settings serialization and deserialization

YoutubeDl.Wpf/Models/Settings.cs

@@ -121,7 +121,7 @@ public class Settings : ReactiveObject
         /// </returns>
         public static async Task<(Settings settings, string? errMsg)> LoadSettingsAsync(CancellationToken cancellationToken = default)
         {
-            var (settings, errMsg) = await FileHelper.LoadJsonAsync<Settings>("Settings.json", FileHelper.commonJsonDeserializerOptions, cancellationToken).ConfigureAwait(false);
+            var (settings, errMsg) = await FileHelper.LoadJsonAsync("Settings.json", SettingsJsonSerializerContext.Default.Settings, cancellationToken).ConfigureAwait(false);
             if (errMsg is null && settings.Version != DefaultVersion)
             {
                 settings.UpdateSettings();
@@ -140,7 +140,7 @@ public static async Task<(Settings settings, string? errMsg)> LoadSettingsAsync(
         /// Null if no errors occurred.
         /// </returns>
         public static Task<string?> SaveSettingsAsync(Settings settings, CancellationToken cancellationToken = default)
-            => FileHelper.SaveJsonAsync("Settings.json", settings, FileHelper.commonJsonSerializerOptions, false, false, cancellationToken);
+            => FileHelper.SaveJsonAsync("Settings.json", settings, SettingsJsonSerializerContext.Default.Settings, false, false, cancellationToken);
 
         /// <summary>
         /// Updates the current object to the latest version.

YoutubeDl.Wpf/Models/SettingsJsonSerializerContext.cs

@@ -0,0 +1,11 @@
+using System.Text.Json.Serialization;
+
+namespace YoutubeDl.Wpf.Models;
+
+[JsonSerializable(typeof(Settings))]
+[JsonSourceGenerationOptions(
+    IgnoreReadOnlyProperties = true,
+    WriteIndented = true)]
+public partial class SettingsJsonSerializerContext : JsonSerializerContext
+{
+}

YoutubeDl.Wpf/Utils/FileHelper.cs

@@ -1,28 +1,14 @@
 using System;
 using System.IO;
-using System.Text.Encodings.Web;
 using System.Text.Json;
+using System.Text.Json.Serialization.Metadata;
 using System.Threading;
 using System.Threading.Tasks;
 
 namespace YoutubeDl.Wpf.Utils
 {
     public static class FileHelper
     {
-        public static readonly JsonSerializerOptions commonJsonSerializerOptions = new()
-        {
-            Encoder = JavaScriptEncoder.UnsafeRelaxedJsonEscaping,
-            IgnoreReadOnlyProperties = true,
-            WriteIndented = true,
-        };
-
-        public static readonly JsonSerializerOptions commonJsonDeserializerOptions = new()
-        {
-            AllowTrailingCommas = true,
-            ReadCommentHandling = JsonCommentHandling.Skip,
-            WriteIndented = true,
-        };
-
         public static readonly string configDirectory;
 
         static FileHelper()
@@ -53,13 +39,13 @@ public static string GetAbsolutePath(string path)
         /// </summary>
         /// <typeparam name="T">Data object type.</typeparam>
         /// <param name="filename">JSON file name.</param>
-        /// <param name="jsonSerializerOptions">Deserialization options.</param>
+        /// <param name="jsonTypeInfo">Metadata about the type to convert.</param>
         /// <param name="cancellationToken">A token that may be used to cancel the read operation.</param>
         /// <returns>
         /// A ValueTuple containing a data object loaded from the JSON file and an error message.
         /// The error message is null if no errors occurred.
         /// </returns>
-        public static async Task<(T, string? errMsg)> LoadJsonAsync<T>(string filename, JsonSerializerOptions? jsonSerializerOptions = null, CancellationToken cancellationToken = default) where T : class, new()
+        public static async Task<(T, string? errMsg)> LoadJsonAsync<T>(string filename, JsonTypeInfo<T> jsonTypeInfo, CancellationToken cancellationToken = default) where T : class, new()
         {
             // extend relative path
             filename = GetAbsolutePath(filename);
@@ -77,7 +63,7 @@ public static async Task<(T, string? errMsg)> LoadJsonAsync<T>(string filename,
             try
             {
                 jsonFile = new(filename, FileMode.Open);
-                jsonData = await JsonSerializer.DeserializeAsync<T>(jsonFile, jsonSerializerOptions, cancellationToken).ConfigureAwait(false);
+                jsonData = await JsonSerializer.DeserializeAsync<T>(jsonFile, jsonTypeInfo, cancellationToken).ConfigureAwait(false);
             }
             catch (Exception ex)
             {
@@ -99,15 +85,15 @@ public static async Task<(T, string? errMsg)> LoadJsonAsync<T>(string filename,
         /// <typeparam name="T">Data object type.</typeparam>
         /// <param name="filename">JSON file name.</param>
         /// <param name="jsonData">The data object to save.</param>
-        /// <param name="jsonSerializerOptions">Serialization options.</param>
+        /// <param name="jsonTypeInfo">Metadata about the type to convert.</param>
         /// <param name="alwaysOverwrite">Always overwrite the original file.</param>
         /// <param name="noBackup">Do not create `filename.old` as backup.</param>
         /// <param name="cancellationToken">A token that may be used to cancel the write operation.</param>
         /// <returns>An error message. Null if no errors occurred.</returns>
         public static async Task<string?> SaveJsonAsync<T>(
             string filename,
             T jsonData,
-            JsonSerializerOptions? jsonSerializerOptions = null,
+            JsonTypeInfo<T> jsonTypeInfo,
             bool alwaysOverwrite = false,
             bool noBackup = false,
             CancellationToken cancellationToken = default)
@@ -134,12 +120,12 @@ public static async Task<(T, string? errMsg)> LoadJsonAsync<T>(string filename,
                 if (alwaysOverwrite || !File.Exists(filename)) // alwaysOverwrite or file doesn't exist. Just write to it.
                 {
                     jsonFile = new(filename, FileMode.Create);
-                    await JsonSerializer.SerializeAsync(jsonFile, jsonData, jsonSerializerOptions, cancellationToken).ConfigureAwait(false);
+                    await JsonSerializer.SerializeAsync(jsonFile, jsonData, jsonTypeInfo, cancellationToken).ConfigureAwait(false);
                 }
                 else // File exists. Write to `filename.new` and then replace with the new file and creates backup `filename.old`.
                 {
                     jsonFile = new($"{filename}.new", FileMode.Create);
-                    await JsonSerializer.SerializeAsync(jsonFile, jsonData, jsonSerializerOptions, cancellationToken).ConfigureAwait(false);
+                    await JsonSerializer.SerializeAsync(jsonFile, jsonData, jsonTypeInfo, cancellationToken).ConfigureAwait(false);
                     jsonFile.Close();
                     File.Replace($"{filename}.new", filename, noBackup ? null : $"{filename}.old");
                 }