unit-testing - HttpClient & 单元测试

Question

Dart、单元测试和一般异步编程的新手。就此而言，还有 StackOverflow。尝试围绕 shelf_route 构建一个 RESTful 服务器并使用 HttpClient 对其进行测试。

我的测试有效，但它们不会自行退出。相反，我必须手动终止该过程。我尝试了几种在网上找到的方法，但没有成功。谁能帮帮我？这是我正在处理的内容:

import 'dart:io';
import 'package:unittest/unittest.dart';
import 'package:shelf/shelf.dart' as shelf;
import 'package:shelf/shelf_io.dart' as io;
import 'package:toner_track/handlers.dart';
import 'package:toner_track/config.dart';

void main() {
  var server;

  group('Server tests', () {
    var server;

    setUp(() {
      var handler = const shelf.Pipeline().addHandler(router);
      io.serve(handler, HOST, PORT).then((s) {
          server = s;
      });
    });

    tearDown(() {
      server.close();
    });

    test('Invalid URL returns 404', () {
      new HttpClient().getUrl(Uri.parse('http://$HOST:$PORT'))
        .then((HttpClientRequest request) => request.close())
        .then(expectAsync((HttpClientResponse response) {
          expect(response.statusCode, equals(404));
        }));
    });

    test('GET /printers returns 200', () {
      new HttpClient().getUrl(Uri.parse('http://$HOST:$PORT$rootPrintersPath'))
      .then((HttpClientRequest request) => request.close())
      .then(expectAsync((HttpClientResponse response) {
        expect(response.statusCode, equals(200));
      }));
    });

    test('POST /printers returns 201', () {
      new HttpClient().postUrl(Uri.parse('http://$HOST:$PORT$rootPrintersPath'))
        .then((HttpClientRequest request) {
          request.write('{"foo": 42}');
          return request.close();
        })
        .then(expectAsync((HttpClientResponse response) {
          expect(response.statusCode, equals(201));
        }));
    });
  });
}

更新:决定放弃 HttpClient 以支持 http 包。使用起来更容易，我的测试现在会自行终止。很明显，我在第一次复飞时没有正确处理某些事情。下面是上面的代码现在的样子:

import 'dart:io';
import 'package:http/http.dart' as http;
import 'package:unittest/unittest.dart';
import 'package:shelf/shelf.dart' as shelf;
import 'package:shelf/shelf_io.dart' as io;
import 'package:toner_track/handlers.dart';
import 'package:toner_track/config.dart';

void main() {
  group('Server tests', () {
    var server;

    setUp(() {
      var handler = const shelf.Pipeline().addHandler(router);
      return io.serve(handler, HOST, PORT).then((s) {
        server = s;
      });
    });

    tearDown(() {
      server.close();
    });

    test('Invalid URL returns 404', () {
      http.get('http://$HOST:$PORT').then(expectAsync((response) {
        expect(response.statusCode, equals(404));
      }));
    });

    test('GET /printers returns 200', () {
      http.get('http://$HOST:$PORT$rootPrintersPath').then(expectAsync((response) {
        expect(response.statusCode, equals(200));
      }));
    });

    test('POST /printers returns 201', () {
      http.post('http://$HOST:$PORT$rootPrintersPath', body: {"foo": "42"}).then(expectAsync((response) {
          expect(response.statusCode, equals(201));
      }));
    });
  });
}

Answer 1

看起来这不是您问题的原因，但如果您在 setUp 中开始异步操作，您应该返回 Future。

return io.serve(handler, HOST, PORT).then((s) {
      server = s;

单元测试框架在开始运行测试之前等待 future 返回。

我认为测试应该做同样的事情。据我所知，有一个开放的错误，对于测试本身，当异步操作开始时返回 Future 就足够了，但它在这里不像 setUp 那样工作。这是不久前的事，所以我认为这是固定的。

test('Invalid URL returns 404', () {
  return new HttpClient().getUrl(Uri.parse('http://$HOST:$PORT'))
    .then((HttpClientRequest request) => request.close())
    .then(expectAsync((HttpClientResponse response) {
      expect(response.statusCode, equals(404));
    }));
});

如果这不起作用

test('POST / ...


test('Invalid URL returns 404', () {
  var cb = new expectAsync((){});

  new HttpClient().getUrl(Uri.parse('http://$HOST:$PORT'))
    .then((HttpClientRequest request) => request.close())
    .then(expectAsync((HttpClientResponse response) {
      expect(response.statusCode, equals(404));
      cb(); // <== to notify the unit test framework that the async operation is finished
    }));
});