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

app/Tests/Serialization/JsonTestRoots.cs

@@ -0,0 +1,81 @@
+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;
+
+namespace AIStudio.Tests.Serialization;
+
+/// <summary>
+/// The types which AI Studio reads or writes as JSON on their own, for the tests which compare the contracts of
+/// System.Text.Json.
+/// </summary>
+/// <remarks>
+/// Only the outermost types belong here: whatever they hold gets checked along with them. Add a type whenever
+/// AI Studio starts to store a new kind of file, with the options it stores the file with.
+/// </remarks>
+public static class JsonTestRoots
+{
+    /// <summary>
+    /// The data AI Studio keeps on the disk of the user.
+    /// </summary>
+    public static IEnumerable<TestCaseData> Stored()
+    {
+        TestHost.PrepareStaticState();
+
+        // Chats, in the workspaces, among the temporary chats, and in chat archives:
+        yield return Case(new(typeof(ChatThread), WorkspaceBehaviour.JSON_OPTIONS));
+
+        // The settings, and their older versions, which the migrations still read:
+        yield return Case(new(typeof(Data), SettingsManager.JSON_OPTIONS));
+        yield return Case(new(typeof(DataV1V3), SettingsManager.JSON_OPTIONS));
+        yield return Case(new(typeof(DataV4), SettingsManager.JSON_OPTIONS));
+        yield return Case(new(typeof(DataV5), SettingsManager.JSON_OPTIONS));
+
+        //
+        // The values of managed settings, which get written and read on their own, as the type of their
+        // setting. That type is often an interface, such as ISet<string>, which the settings themselves
+        // never use:
+        //
+        foreach (var valueType in ManagedSettingValueTypes())
+            yield return Case(new(valueType, SettingsManager.JSON_OPTIONS));
+
+        // The SWOT analysis, which a chat stores as the presentation of a message:
+        yield return Case(new(typeof(SwotAnalysisResult), SwotAnalysisContentPresentation.JSON_OPTIONS), "read");
+        yield return Case(new(typeof(SwotAnalysisResult), SwotAnalysisContentPresentation.WRITE_OPTIONS), "written");
+
+        // Backups and their restore:
+        yield return Case(new(typeof(DataBackupManifest), DataBackupFormat.JSON_OPTIONS));
+        yield return Case(new(typeof(DataRestorePlan), DataBackupFormat.JSON_OPTIONS));
+        yield return Case(new(typeof(DataRestoreReport), DataBackupFormat.JSON_OPTIONS));
+
+        // The text around a passage which the provenance store keeps:
+        yield return Case(new(typeof(IReadOnlyList<string>), SqliteProvenanceStoreClientImplementation.JSON_OPTIONS));
+        yield return Case(new(typeof(List<string>), SqliteProvenanceStoreClientImplementation.JSON_OPTIONS));
+    }
+
+    private static TestCaseData Case(JsonTestRoot root, string? purpose = null)
+    {
+        //
+        // The same System.Text.Json does with the first call of Serialize or Deserialize. Only then, the
+        // options hand out contracts:
+        //
+        root.Options.MakeReadOnly(populateMissingResolver: true);
+        return new TestCaseData(root).SetArgDisplayNames(purpose is null ? root.ToString() : $"{root}, {purpose}");
+    }
+
+    private static IEnumerable<Type> ManagedSettingValueTypes()
+    {
+        //
+        // Creating the settings registers every managed setting, just like the start of the app does:
+        //
+        _ = new Data();
+        return ManagedConfiguration.RegisteredSettings
+            .Select(setting => setting.GetType().GetGenericArguments()[1])
+            .Distinct()
+            .OrderBy(JsonContractDescription.TypeName, StringComparer.Ordinal);
+    }
+}