Generated the JSON contracts of providers, the runtime, and services at compile time (#1150)

app/Tests/Serialization/JsonGoldenRequestTests.cs

@@ -0,0 +1,45 @@
+using System.Text.Json;
+
+using AIStudio.Provider;
+using AIStudio.Tools.Rust;
+using AIStudio.Tools.Services;
+
+namespace AIStudio.Tests.Serialization;
+
+/// <summary>
+/// Writes requests the way AI Studio sends them, and checks that they get sent just as before.
+/// </summary>
+/// <remarks>
+/// The files in the folder Fixtures were written with the contracts of reflection, before AI Studio got
+/// contracts of its own. A provider or the runtime reads every byte of a request, and one which got written
+/// otherwise, e.g., with a field under another name or without the tools, gets refused or misread. The requests
+/// are made up, see <see cref="JsonSampleRequests"/>.
+/// </remarks>
+[TestFixture]
+public sealed class JsonGoldenRequestTests
+{
+    private static IEnumerable<JsonGoldenRequest> GoldenRequests()
+    {
+        TestHost.PrepareStaticState();
+        yield return new("chat-completion-request.json", JsonSampleRequests.ChatCompletion, ProviderJsonOptions.OPTIONS);
+        yield return new("responses-request.json", JsonSampleRequests.Responses, ProviderJsonOptions.OPTIONS);
+        yield return new("anthropic-messages-request.json", () => JsonSampleRequests.Anthropic(), ProviderJsonOptions.OPTIONS);
+        yield return new("embedding-request.json", JsonSampleRequests.Embedding, ProviderJsonOptions.OPTIONS);
+        yield return new("google-embedding-request.json", JsonSampleRequests.GoogleEmbedding, ProviderJsonOptions.OPTIONS);
+
+        // The requests to the runtime which were anonymous types once:
+        yield return new("runtime-validate-tokenizer-request.json", () => new ValidateTokenizerRequest("/samples/tokenizer.json"), RustService.JSON_OPTIONS);
+        yield return new("runtime-store-tokenizer-request.json", () => new StoreTokenizerRequest("model-a", "/samples/tokenizer.json"), RustService.JSON_OPTIONS);
+        yield return new("runtime-delete-tokenizer-request.json", () => new DeleteTokenizerRequest("model-a"), RustService.JSON_OPTIONS);
+        yield return new("runtime-count-tokens-request.json", () => new CountTokensRequest("Count these tokens.", "/samples/tokenizer.json"), RustService.JSON_OPTIONS);
+        yield return new("runtime-prepare-image-request.json", () => new PrepareImageRequest("/samples/picture.png", true), RustService.JSON_OPTIONS);
+        yield return new("runtime-prepare-image-for-model-request.json", () => new PrepareImageForModelRequest("/samples/picture.png", 5_242_880), RustService.JSON_OPTIONS);
+    }
+
+    [TestCaseSource(nameof(GoldenRequests))]
+    public void ARequestIsSentAsBefore(JsonGoldenRequest goldenRequest)
+    {
+        var request = goldenRequest.Create();
+        Assert.That(JsonSerializer.Serialize(request, request.GetType(), goldenRequest.Options), Is.EqualTo(JsonGoldenFileTests.ReadFixture(goldenRequest.FileName)));
+    }
+}