halkyon/packages/halkyon_llm/test/testing_test.dart

import 'package:halkyon_llm/halkyon_llm.dart';
import 'package:halkyon_llm/testing.dart';
import 'package:test/test.dart';

final _endpoint = LlmEndpoint(
  protocol: LlmProtocol.openai,
  model: 'm',
  apiKey: 'k',
);
final _request = LlmRequest(
  messages: [
    LlmMessage.user([const LlmText('?')]),
  ],
  maxOutputTokens: 10,
);

void main() {
  group('FakeLlmClient', () {
    test('answers with the text scripted, in pieces, and keeps what it was '
        'sent', () async {
      final client = FakeLlmClient()..replyText('Hallo Welt');
      final events = await client.send(_endpoint, _request).toList();
      expect(
        events.whereType<LlmTextDelta>().map((delta) => delta.text).join(),
        'Hallo Welt',
      );
      expect((events.last as LlmFinished).message.text, 'Hallo Welt');
      expect(client.sent.single, (_endpoint, _request));
      expect(client.allReplied, isTrue);
    });

    test('fails as scripted, with what was counted', () {
      final client = FakeLlmClient()
        ..fail(
          LlmFailureKind.rateLimited,
          usage: const LlmUsage(inputTokens: 5, outputTokens: 0),
        );
      expect(
        client.send(_endpoint, _request).toList(),
        throwsA(
          isA<LlmFailure>()
              .having((f) => f.kind, 'kind', LlmFailureKind.rateLimited)
              .having((f) => f.usage.inputTokens, 'input', 5),
        ),
      );
    });

    test('counts answers cancelled before they ended', () async {
      final client = FakeLlmClient()..replyText('Hallo Welt');
      await client.send(_endpoint, _request).first;
      expect(client.cancelled, 1);
    });

    test('refuses a request nothing was scripted for', () {
      expect(
        () => FakeLlmClient().send(_endpoint, _request),
        throwsStateError,
      );
    });

    test("refuses an effort the endpoint's host takes not, as HTTP's does", () {
      final client = FakeLlmClient()..replyText('Hallo');
      expect(
        () => client.send(
          LlmEndpoint(
            protocol: LlmProtocol.openai,
            model: 'm',
            apiKey: 'k',
            baseUrl: 'https://api.mistral.ai/v1',
          ),
          LlmRequest(
            messages: _request.messages,
            maxOutputTokens: 10,
            effort: LlmEffort.low,
          ),
        ),
        throwsArgumentError,
      );
      expect(client.sent, isEmpty);
    });
  });
}