Move JSON stores to source generation (trim-prep)

CHANGELOG.md

@@ -7,6 +7,15 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Changed
+- **JSON stores moved to System.Text.Json source generation.** `JsonSnipStore`
+  and `JsonSettingsStore` now serialise via a generated `JsonSerializerContext`
+  instead of the reflection-based serializer, removing the IL2026 trim warnings.
+  The on-disk format is unchanged (proven byte-identical by tests, with enum
+  names pinned via `[JsonStringEnumMemberName]`), so existing stores keep
+  loading. `PublishTrimmed` stays off: a trimmed WinUI publish still trips
+  IL2104 on the WinAppSDK/WinRT/Jdenticon assemblies, which aren't trim-safe.
+
 ### Added
 - **Markdown rendering for snip descriptions.** A snip's description is now
   rendered as Markdown (headings, bold/italic, inline and block code, links,

src/Snipdeck.App/Snipdeck.App.csproj

@@ -45,12 +45,15 @@
 	<PropertyGroup>
 		<PublishReadyToRun Condition="'$(Configuration)' == 'Debug'">False</PublishReadyToRun>
 		<PublishReadyToRun Condition="'$(Configuration)' != 'Debug'">True</PublishReadyToRun>
-		<!-- Trimming is disabled until we move JSON serialisation onto
-		     System.Text.Json source-gen (JsonSerializerContext). The
-		     untyped Serialize/DeserializeAsync overloads are IL2026'd
-		     and Jdenticon / Microsoft.Windows.SDK.NET / WinRT.Runtime
-		     also produce trim warnings, which TreatWarningsAsErrors
-		     promotes into a failed publish. -->
+		<!-- PublishTrimmed stays off. The JSON stores now serialise via source-gen
+		     (StoreJsonContext), which removed the IL2026 reflection warnings — but a
+		     trimmed Release publish still fails on IL2104 from Microsoft.Windows.SDK.NET,
+		     WinRT.Runtime and Jdenticon, which aren't annotated trim-safe. Silencing
+		     those wouldn't make trimming safe: the WinRT interop layer uses reflection,
+		     so full trimming risks runtime breakage that can't be caught by a build.
+		     A WinUI head can't be fully trimmed without partial-trim (which only trims
+		     our own tiny assemblies, so negligible savings). Revisit only if the
+		     WinAppSDK/WinRT assemblies ship trim annotations. -->
 		<PublishTrimmed>False</PublishTrimmed>
 	</PropertyGroup>
 </Project>

src/Snipdeck.Core/Models/CloseBehaviour.cs

@@ -1,8 +1,13 @@
+using System.Text.Json.Serialization;
+
 namespace Snipdeck.Core.Models
 {
     public enum CloseBehaviour
     {
+        [JsonStringEnumMemberName("hideToTray")]
         HideToTray = 0,
+
+        [JsonStringEnumMemberName("exit")]
         Exit = 1,
     }
 }

src/Snipdeck.Core/Models/HotkeyBinding.cs

@@ -1,12 +1,23 @@
+using System.Text.Json.Serialization;
+
 namespace Snipdeck.Core.Models
 {
     [Flags]
     public enum HotkeyModifiers
     {
+        [JsonStringEnumMemberName("none")]
         None = 0,
+
+        [JsonStringEnumMemberName("alt")]
         Alt = 1,
+
+        [JsonStringEnumMemberName("control")]
         Control = 2,
+
+        [JsonStringEnumMemberName("shift")]
         Shift = 4,
+
+        [JsonStringEnumMemberName("windows")]
         Windows = 8,
     }
 

src/Snipdeck.Core/Models/ParameterType.cs

@@ -1,8 +1,13 @@
+using System.Text.Json.Serialization;
+
 namespace Snipdeck.Core.Models
 {
     public enum ParameterType
     {
+        [JsonStringEnumMemberName("text")]
         Text = 0,
+
+        [JsonStringEnumMemberName("choice")]
         Choice = 1,
     }
 }

src/Snipdeck.Core/Models/ThemePreference.cs

@@ -1,9 +1,16 @@
+using System.Text.Json.Serialization;
+
 namespace Snipdeck.Core.Models
 {
     public enum ThemePreference
     {
+        [JsonStringEnumMemberName("system")]
         System = 0,
+
+        [JsonStringEnumMemberName("light")]
         Light = 1,
+
+        [JsonStringEnumMemberName("dark")]
         Dark = 2,
     }
 }

src/Snipdeck.Core/Services/JsonSettingsStore.cs

@@ -1,5 +1,4 @@
 using System.Text.Json;
-using System.Text.Json.Serialization;
 
 using Snipdeck.Core.Abstractions;
 using Snipdeck.Core.Models;
@@ -8,16 +7,6 @@ namespace Snipdeck.Core.Services
 {
     public sealed class JsonSettingsStore : ISettingsStore, IDisposable
     {
-        private static readonly JsonSerializerOptions _serializerOptions = new()
-        {
-            WriteIndented = true,
-            PropertyNamingPolicy = JsonNamingPolicy.CamelCase,
-            Converters =
-            {
-                new JsonStringEnumConverter(JsonNamingPolicy.CamelCase),
-            },
-        };
-
         private readonly SemaphoreSlim _gate = new(1, 1);
 
         public JsonSettingsStore(string filePath)
@@ -45,7 +34,7 @@ public async Task<AppConfig> LoadAsync(CancellationToken cancellationToken = def
                     FileShare.Read);
 
                 var config = await JsonSerializer
-                    .DeserializeAsync<AppConfig>(stream, _serializerOptions, cancellationToken)
+                    .DeserializeAsync(stream, StoreJsonContext.Default.AppConfig, cancellationToken)
                     .ConfigureAwait(false);
 
                 if (config is null)
@@ -92,7 +81,7 @@ public async Task SaveAsync(AppConfig config, CancellationToken cancellationToke
                     FileShare.None))
                 {
                     await JsonSerializer
-                        .SerializeAsync(stream, config, _serializerOptions, cancellationToken)
+                        .SerializeAsync(stream, config, StoreJsonContext.Default.AppConfig, cancellationToken)
                         .ConfigureAwait(false);
                     await stream.FlushAsync(cancellationToken).ConfigureAwait(false);
                 }

src/Snipdeck.Core/Services/JsonSnipStore.cs

@@ -1,5 +1,4 @@
 using System.Text.Json;
-using System.Text.Json.Serialization;
 
 using Snipdeck.Core.Abstractions;
 using Snipdeck.Core.Models;
@@ -8,13 +7,6 @@ namespace Snipdeck.Core.Services
 {
     public sealed class JsonSnipStore : ISnipStore, IDisposable
     {
-        private static readonly JsonSerializerOptions _serializerOptions = new()
-        {
-            WriteIndented = true,
-            PropertyNamingPolicy = JsonNamingPolicy.CamelCase,
-            Converters = { new JsonStringEnumConverter(JsonNamingPolicy.CamelCase) },
-        };
-
         private readonly SemaphoreSlim _gate = new(1, 1);
 
         public JsonSnipStore(string filePath)
@@ -42,7 +34,7 @@ public async Task<SnipStoreDocument> LoadAsync(CancellationToken cancellationTok
                     FileShare.Read);
 
                 var document = await JsonSerializer
-                    .DeserializeAsync<SnipStoreDocument>(stream, _serializerOptions, cancellationToken)
+                    .DeserializeAsync(stream, StoreJsonContext.Default.SnipStoreDocument, cancellationToken)
                     .ConfigureAwait(false)
                     ?? new SnipStoreDocument();
 
@@ -80,7 +72,7 @@ public async Task SaveAsync(SnipStoreDocument document, CancellationToken cancel
                     FileShare.None))
                 {
                     await JsonSerializer
-                        .SerializeAsync(stream, document, _serializerOptions, cancellationToken)
+                        .SerializeAsync(stream, document, StoreJsonContext.Default.SnipStoreDocument, cancellationToken)
                         .ConfigureAwait(false);
                     await stream.FlushAsync(cancellationToken).ConfigureAwait(false);
                 }

src/Snipdeck.Core/Services/StoreJsonContext.cs

@@ -0,0 +1,26 @@
+using System.Text.Json.Serialization;
+
+using Snipdeck.Core.Models;
+
+namespace Snipdeck.Core.Services
+{
+    /// <summary>
+    /// System.Text.Json source-generated metadata for the persisted documents.
+    /// Using generated <see cref="System.Text.Json.Serialization.Metadata.JsonTypeInfo{T}"/>
+    /// instead of the reflection-based serializer keeps the JSON stores trim-safe
+    /// (no IL2026) so the app can be published with PublishTrimmed.
+    ///
+    /// The options here must reproduce the previous reflection serializer's wire
+    /// format exactly (camelCase properties, camelCase string enums) so existing
+    /// store/settings files keep loading — see StoreJsonCompatibilityTests.
+    /// </summary>
+    [JsonSourceGenerationOptions(
+        WriteIndented = true,
+        PropertyNamingPolicy = JsonKnownNamingPolicy.CamelCase,
+        UseStringEnumConverter = true)]
+    [JsonSerializable(typeof(SnipStoreDocument))]
+    [JsonSerializable(typeof(AppConfig))]
+    public sealed partial class StoreJsonContext : JsonSerializerContext
+    {
+    }
+}

tests/Snipdeck.Core.Tests/Services/StoreJsonCompatibilityTests.cs

@@ -0,0 +1,102 @@
+using System.Text.Json;
+using System.Text.Json.Serialization;
+
+using Snipdeck.Core.Models;
+using Snipdeck.Core.Services;
+
+namespace Snipdeck.Core.Tests.Services
+{
+    /// <summary>
+    /// Proves the source-generated <see cref="StoreJsonContext"/> serializes
+    /// byte-for-byte identically to the previous reflection-based serializer, so
+    /// existing store/settings files on disk keep loading after the switch. Runs
+    /// entirely on Linux, which de-risks the format change that the trimmed
+    /// publish (PublishTrimmed) depends on.
+    /// </summary>
+    public class StoreJsonCompatibilityTests
+    {
+        // Mirrors the options the JSON stores used before source-gen.
+        private static readonly JsonSerializerOptions _legacyOptions = new()
+        {
+            WriteIndented = true,
+            PropertyNamingPolicy = JsonNamingPolicy.CamelCase,
+            Converters = { new JsonStringEnumConverter(JsonNamingPolicy.CamelCase) },
+        };
+
+        private static SnipStoreDocument SampleDocument()
+        {
+            var cli = new Cli { Name = "pl-app", IconRef = "icons/pl.png" };
+            return new SnipStoreDocument
+            {
+                Clis = [cli],
+                Snips =
+                [
+                    new Snip
+                    {
+                        CliId = cli.Id,
+                        Title = "Deploy",
+                        CommandTemplate = "pl-app deploy --env {env}",
+                        Description = "Deploys to **{env}**.",
+                        Parameters =
+                        [
+                            new Parameter
+                            {
+                                Name = "env",
+                                Type = ParameterType.Choice,
+                                Options = ["dev", "prod"],
+                                Default = "dev",
+                            },
+                        ],
+                        Tags = ["deploy", "ops"],
+                        IsFavourite = true,
+                        IsTrash = false,
+                        UsageCount = 3,
+                        LastUsedAt = new DateTimeOffset(2026, 5, 30, 9, 0, 0, TimeSpan.Zero),
+                    },
+                ],
+            };
+        }
+
+        private static AppConfig SampleConfig() => new()
+        {
+            StoragePath = @"C:\data\store.json",
+            BackupRetention = 25,
+            Theme = ThemePreference.Dark,
+            CloseBehaviour = CloseBehaviour.HideToTray,
+            Hotkey = HotkeyBinding.Default,
+        };
+
+        [Fact]
+        public void Document_source_gen_output_is_byte_identical_to_legacy()
+        {
+            var doc = SampleDocument();
+            var legacy = JsonSerializer.Serialize(doc, _legacyOptions);
+            var generated = JsonSerializer.Serialize(doc, StoreJsonContext.Default.SnipStoreDocument);
+            Assert.Equal(legacy, generated);
+        }
+
+        [Fact]
+        public void Config_source_gen_output_is_byte_identical_to_legacy()
+        {
+            var config = SampleConfig();
+            var legacy = JsonSerializer.Serialize(config, _legacyOptions);
+            var generated = JsonSerializer.Serialize(config, StoreJsonContext.Default.AppConfig);
+            Assert.Equal(legacy, generated);
+        }
+
+        [Fact]
+        public void Legacy_json_round_trips_through_the_source_gen_context()
+        {
+            var doc = SampleDocument();
+            var legacyJson = JsonSerializer.Serialize(doc, _legacyOptions);
+
+            var restored = JsonSerializer.Deserialize(legacyJson, StoreJsonContext.Default.SnipStoreDocument);
+
+            Assert.NotNull(restored);
+            Assert.Equal("pl-app", restored!.Clis[0].Name);
+            Assert.Equal(ParameterType.Choice, restored.Snips[0].Parameters[0].Type);
+            Assert.True(restored.Snips[0].IsFavourite);
+            Assert.Equal(doc.Snips[0].LastUsedAt, restored.Snips[0].LastUsedAt);
+        }
+    }
+}