the-mews/app/test/fetch_actor_test.dart

import 'dart:async';
import 'dart:convert';
import 'dart:io';

import 'package:actors/actors.dart';
import 'package:flutter_test/flutter_test.dart';

import 'package:mews/application/actors/fetch_actor.dart';
import 'package:mews/mews/document.dart';

import 'fake_protocol_server.dart';

const page = '''
<?xml version="1.0" encoding="UTF-8"?>
<html xmlns="http://www.w3.org/1999/xhtml">
  <head><title>Parsed</title><meta name="mews-profile" content="0.1" /></head>
  <body><p>Some content.</p></body>
</html>
''';

const gemtext = '# Title\n\nSome text.\n';

void main() {
  test('ParseSource parses without touching the network', () async {
    final actor = Actor.create(FetchHandler.new);
    addTearDown(actor.close);

    final result = await actor
        .send(const ParseSource(url: 'https://example.com/parsed.html', source: page));

    expect(result, isA<FetchPageOk>());
    final ok = result as FetchPageOk;
    expect(ok.page.title, 'Parsed');
    expect(ok.page.isMews, isTrue);
    expect(ok.notModified, isFalse);
  });

  test('ParseSource offers a web page as a simplified page', () async {
    final actor = Actor.create(FetchHandler.new);
    addTearDown(actor.close);

    final result = await actor.send(const ParseSource(
        url: 'https://example.com/broken.html',
        source: '<h1>Loose</h1><p>Never closed'));

    expect(result, isA<FetchParseError>());
    final error = result as FetchParseError;
    // No conformance marker, so this is an ordinary web page rather than a
    // Mews page with a markup error.
    expect(error.declaresMews, isFalse);
    expect(error.simplified, isNotNull);
    expect(error.simplified!.body.whereType<HeadingBlock>(), isNotEmpty);
  });

  test('ParseSource reports a markup error on a page claiming Mews', () async {
    final actor = Actor.create(FetchHandler.new);
    addTearDown(actor.close);

    final result = await actor.send(const ParseSource(
        url: 'https://example.com/broken.html',
        source: '<html><head><title>T</title>'
            '<meta name="mews-profile" content="0.1"></head>'
            '<body><p>Never closed</body></html>'));

    expect(result, isA<FetchParseError>());
    expect((result as FetchParseError).declaresMews, isTrue);
  });

  // The protocol transports are exercised through the same handler a fetch
  // uses, against in-process servers, so these tests cover the whole path
  // from command to page.
  group('protocol dispatch', () {
    final handler = FetchHandler();
    StreamSubscription<Socket>? spartanAnswers;
    StreamSubscription<SecureSocket>? geminiAnswers;
    FakeSpartanServer? spartan;
    FakeGeminiServer? geminiServer;

    tearDown(() async {
      await spartanAnswers?.cancel();
      await geminiAnswers?.cancel();
      await spartan?.close();
      await geminiServer?.close();
    });

    test('a spartan page becomes a gemtext page', () async {
      final server = FakeSpartanServer();
      await server.start();
      spartan = server;
      spartanAnswers = server
          .answer((line, upload, socket) => socket.add(utf8.encode('2 text/gemini\r\n$gemtext')));

      final result = await handler.handle(FetchPage(url: 'spartan://localhost:${server.port}/'));

      expect(result, isA<FetchPageOk>());
      final ok = result as FetchPageOk;
      expect(ok.page.title, 'Title');
      expect(ok.page.isMews, isTrue);
      expect(ok.page.body.first, isA<HeadingBlock>());
      expect(ok.source, gemtext);
    });

    test('a spartan error status carries its message', () async {
      final server = FakeSpartanServer();
      await server.start();
      spartan = server;
      spartanAnswers = server
          .answer((line, upload, socket) => socket.add(utf8.encode('4 Nothing lives here\r\n')));

      final result =
          await handler.handle(FetchPage(url: 'spartan://localhost:${server.port}/gone'));

      expect(result, isA<FetchProtocolError>());
      expect((result as FetchProtocolError).message, 'Nothing lives here');
    });

    test('a gemini input request becomes a one-field form', () async {
      final server = FakeGeminiServer('gemini-test-a');
      await server.start();
      geminiServer = server;
      geminiAnswers =
          server.answer((line, socket) => socket.add(utf8.encode('10 Enter a word\r\n')));

      final result =
          await handler.handle(FetchPage(url: 'gemini://localhost:${server.port}/ask'));

      expect(result, isA<FetchPageOk>());
      final form = (result as FetchPageOk).page.body.single as FormBlock;
      final field = form.fields.single as MewsTextField;
      expect(field.name, 'query');
      expect(field.password, isFalse);
      expect(field.label, 'Enter a word');
    });

    test('a sensitive gemini input asks quietly', () async {
      final server = FakeGeminiServer('gemini-test-a');
      await server.start();
      geminiServer = server;
      geminiAnswers = server.answer((line, socket) => socket.add(utf8.encode('11 A secret\r\n')));

      final result =
          await handler.handle(FetchPage(url: 'gemini://localhost:${server.port}/ask'));

      final form = (result as FetchPageOk).page.body.single as FormBlock;
      expect((form.fields.single as MewsTextField).password, isTrue);
    });

    test('the first visit to a gemini host reports a pin to save', () async {
      final server = FakeGeminiServer('gemini-test-a');
      await server.start();
      geminiServer = server;
      geminiAnswers = server
          .answer((line, socket) => socket.add(utf8.encode('20 text/gemini\r\n$gemtext')));

      final result = await handler.handle(FetchPage(url: 'gemini://localhost:${server.port}/'));

      final ok = result as FetchPageOk;
      expect(ok.pinUpdates, hasLength(1));
      expect(ok.pinUpdates.single.host, 'localhost');
      expect(ok.pinUpdates.single.port, server.port);
    });

    test('a gemini site asking for a certificate gets the bound identity', () async {
      final server = FakeGeminiServer('gemini-test-a', clientCertName: 'client-test');
      await server.start();
      geminiServer = server;
      geminiAnswers = server.answer((line, socket) {
        // The server asks but never checks: an identity is offered or not.
        if (socket.peerCertificate == null) {
          socket.add(utf8.encode('60 Who are you\r\n'));
        } else {
          socket.add(utf8.encode('20 text/gemini\r\n$gemtext'));
        }
      });

      // Without an identity, the request comes back to the reader as a
      // choice to make.
      final asked =
          await handler.handle(FetchPage(url: 'gemini://localhost:${server.port}/'));
      expect(asked, isA<FetchClientCertificateRequired>());
      expect((asked as FetchClientCertificateRequired).status, 60);

      // With the identity, the page arrives wearing it.
      final cert = File('test/fixtures/client-test-cert.pem').readAsStringSync();
      final key = File('test/fixtures/client-test-key.pem').readAsStringSync();
      final ok = await handler.handle(FetchPage(
          url: 'gemini://localhost:${server.port}/', clientCert: cert, clientKey: key));
      expect(ok, isA<FetchPageOk>());
      expect((ok as FetchPageOk).page.title, 'Title');
    });

    test('a capsule image arrives as bytes', () async {
      final server = FakeSpartanServer();
      await server.start();
      spartan = server;
      final png = base64.decode(
          'iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mNkYPhfDwAChwGA60e6kgAAAABJRU5ErkJggg==');
      spartanAnswers = server.answer((line, upload, socket) => socket.add([
            ...utf8.encode('2 image/png\r\n'),
            ...png,
          ]));

      final result = await handler
          .handle(FetchBytes(url: 'spartan://localhost:${server.port}/dot.png'));

      expect(result, isA<FetchBytesOk>());
      expect((result as FetchBytesOk).data, png);
    });

    test('a gemini form answers as a query string', () async {
      final server = FakeGeminiServer('gemini-test-a');
      await server.start();
      geminiServer = server;
      var asked = '';
      geminiAnswers = server.answer((line, socket) {
        asked = line;
        socket.add(utf8.encode('20 text/gemini\r\n$gemtext'));
      });

      final result = await handler.handle(SubmitForm(
          url: 'gemini://localhost:${server.port}/ask',
          method: 'get',
          fields: {'query': 'phones'}));

      // The fake reads whole lines, so the CRLF is already stripped.
      expect(asked, 'gemini://localhost:${server.port}/ask?query=phones');
      expect(result, isA<FetchPageOk>());
    });
  });
}