Generated the JSON contracts of the stored data at compile time (#1148)

app/Tests/Serialization/JsonGoldenFileTests.cs

@@ -0,0 +1,89 @@
+using System.Runtime.CompilerServices;
+using System.Text.Json;
+using System.Text.Json.Nodes;
+
+using AIStudio.Assistants.SWOTAnalysis;
+using AIStudio.Chat;
+using AIStudio.Settings;
+using AIStudio.Settings.DataModel;
+using AIStudio.Settings.DataModel.PreviousModels;
+using AIStudio.Tools;
+using AIStudio.Tools.Databases.ProvenanceStore;
+using AIStudio.Tools.DataBackup;
+
+using Microsoft.Extensions.Logging.Abstractions;
+
+using Version = AIStudio.Settings.Version;
+
+namespace AIStudio.Tests.Serialization;
+
+/// <summary>
+/// Reads and writes stored files of AI Studio, and checks that nothing gets lost and nothing gets written
+/// otherwise than with the contracts of reflection.
+/// </summary>
+/// <remarks>
+/// The files in the folder Fixtures were written with the contracts of reflection, before AI Studio got
+/// contracts of its own, and every property holds a value. They are made up: no real chat or setting of
+/// anybody is among them. A property added later is missing in them, which the tests allow.
+/// </remarks>
+[TestFixture]
+public sealed class JsonGoldenFileTests
+{
+    private static IEnumerable<JsonGoldenFile> GoldenFiles()
+    {
+        TestHost.PrepareStaticState();
+        yield return new("settings.json", typeof(Data), SettingsManager.JSON_OPTIONS);
+        yield return new("settings-v1.json", typeof(DataV1V3), SettingsManager.JSON_OPTIONS);
+        yield return new("settings-v4.json", typeof(DataV4), SettingsManager.JSON_OPTIONS);
+        yield return new("settings-v5.json", typeof(DataV5), SettingsManager.JSON_OPTIONS);
+        yield return new("chat.json", typeof(ChatThread), WorkspaceBehaviour.JSON_OPTIONS);
+        yield return new("swot-analysis.json", typeof(SwotAnalysisResult), SwotAnalysisContentPresentation.JSON_OPTIONS);
+        yield return new("data-backup-manifest.json", typeof(DataBackupManifest), DataBackupFormat.JSON_OPTIONS);
+        yield return new("data-restore-plan.json", typeof(DataRestorePlan), DataBackupFormat.JSON_OPTIONS);
+        yield return new("data-restore-report.json", typeof(DataRestoreReport), DataBackupFormat.JSON_OPTIONS);
+        yield return new("provenance-surrounding-content.json", typeof(List<string>), SqliteProvenanceStoreClientImplementation.JSON_OPTIONS);
+    }
+
+    [TestCaseSource(nameof(GoldenFiles))]
+    public void AStoredFileIsWrittenAgainAsWithReflection(JsonGoldenFile goldenFile)
+    {
+        var json = ReadFixture(goldenFile.FileName);
+        var baseline = JsonReflectionBaseline.Of(goldenFile.Options);
+
+        var writtenAgain = JsonSerializer.Serialize(JsonSerializer.Deserialize(json, goldenFile.Type, goldenFile.Options), goldenFile.Type, goldenFile.Options);
+        var writtenAgainByReflection = JsonSerializer.Serialize(JsonSerializer.Deserialize(json, goldenFile.Type, baseline), goldenFile.Type, baseline);
+
+        Assert.That(writtenAgain, Is.EqualTo(writtenAgainByReflection));
+    }
+
+    [TestCaseSource(nameof(GoldenFiles))]
+    public void AStoredFileKeepsAllItsValues(JsonGoldenFile goldenFile)
+    {
+        var json = ReadFixture(goldenFile.FileName);
+        var writtenAgain = JsonSerializer.Serialize(JsonSerializer.Deserialize(json, goldenFile.Type, goldenFile.Options), goldenFile.Type, goldenFile.Options);
+
+        Assert.That(JsonContainment.FindMissing(JsonNode.Parse(json), JsonNode.Parse(writtenAgain)), Is.Empty);
+    }
+
+    [TestCase("settings-v1.json", Version.V1)]
+    [TestCase("settings-v4.json", Version.V4)]
+    [TestCase("settings-v5.json", Version.V5)]
+    public void OldSettingsMigrateAsWithReflection(string fileName, Version version)
+    {
+        var json = ReadFixture(fileName);
+        var baseline = JsonReflectionBaseline.Of(SettingsManager.JSON_OPTIONS);
+
+        var migrated = SettingsMigrations.Migrate(NullLogger<SettingsManager>.Instance, version, json, SettingsManager.JSON_OPTIONS);
+        var migratedByReflection = SettingsMigrations.Migrate(NullLogger<SettingsManager>.Instance, version, json, baseline);
+
+        Assert.That(JsonSerializer.Serialize(migrated, SettingsManager.JSON_OPTIONS), Is.EqualTo(JsonSerializer.Serialize(migratedByReflection, baseline)));
+    }
+
+    /// <summary>
+    /// Reads a file from the fixtures next to this test.
+    /// </summary>
+    /// <remarks>
+    /// Read from the source tree, the way the other fixtures are, so the file needs no entry in the project file.
+    /// </remarks>
+    private static string ReadFixture(string fileName, [CallerFilePath] string sourceFilePath = "") => File.ReadAllText(Path.Combine(Path.GetDirectoryName(sourceFilePath)!, "Fixtures", fileName));
+}