javascript - 如何使用 mocha 和 should.js 与 sails.js 编写二进制下载测试？

Question

我正在尝试为下载用户头像图像的 Sails.Js Controller 操作编写测试。 Controller 操作如下所示:

/**
* Download avatar of the user with the specified id
*
* (GET /user/:id/avatar)
*/
avatar: function (req, res) {

  req.validate({
    id: 'string'
  });

  User.findOne(req.param('id')).exec(function (err, user){
        if (err) return res.negotiate(err);
        if (!user) return res.notFound();

        // User has no avatar image uploaded.
        // (should have never have hit this endpoint and used the default image)
        if (!user.avatarFd) {
          return res.notFound();
        }

        var SkipperDisk = require('skipper-disk');
        var fileAdapter = SkipperDisk(/* optional opts */);

        // Stream the file down
        fileAdapter.read(user.avatarFd)
        .on('error', function (err){
          return res.serverError(err);
        })
        .pipe(res);
    });
}

到目前为止，测试看起来像这样:

describe('try to download a user avatar', function() {
    var result;
    it('should return 200', function(done) {
        server
            .get('/user/' + testUser.id + '/avatar')
            .expect(200)
            .end(function(err, res) {
                if (err) return done(err);
                result = res.body;
                return done();
            });
        }
    }
    it('should return binary data stream', function(done) {
      // make some assertions.
    });
});

我想添加另一个测试以确保返回的是二进制数据，但我不知道如何完成。有人知道解决这个问题的正确方法吗？

更新

在尝试了@sgress454 在下面建议的模式下的解决方案后，我完成了这个测试:

tmp = require('temporary'); 
  // https://github.com/vesln/temporary

// Write nonsense bytes to a file fixture.
var EOF = '\x04';
var size = 1000;
var fileFixture = new tmp.File();
fileFixture.writeFileSync(crypto.pseudoRandomBytes(size) + EOF);
fileFixture.size = size;

after(function() {
fileFixture.unlinkSync();
});

describe('try to download a user avatar', function() {
    var download;
    it('should return 200', function(done) {
        server
            .get('/user/' + testUser.id + '/avatar')
            .expect(200)
            .end(function(err, res) {
                if (err) return done(err);
                download = new Buffer(res.text, 'ascii');
                return done();
            });
        });
    it('should return binary stream', function(done) {
        var testAvatar = fs.readFileSync(fileFixture.path);
        download.toString('base64').should.be.equal(testAvatar.toString('base64'));
        done(); 
    });
});

因此此测试使用 temporary 模拟了一个文件.问题是，当我比较从服务器返回的结果和我从模拟文件系统读取的模拟文件时，它们是不一样的。我得到了预期的结果:

  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

下面是实际响应:

  -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

我不确定为什么此时文件会有所不同。也许问题出在我解析返回数据的方式上？

Answer 1

这是最明显的解决方案最好的情况之一:使用 Controller 操作下载测试中的已知文件，然后在测试中从磁盘加载同一文件并将其与下载的文件进行比较.您将在测试目录的某个地方(可能在 fixtures 子目录下)保存一个头像文件，并确保在测试运行之前，创建了一个用户，其 avatarFd 点到那个文件。然后，进行第二个测试的最简单(效率最低)的方法就是让第一个测试保持原样，然后重新运行请求:

it('should return binary data stream', function(done) {
    server
      .get('/user/' + testUser.id + '/avatar')
      .end(function(err, res) {
          if (err) return done(err);
          result = res.text;
          var testAvatar = require('fs').readFileSync(pathToTestAvatar);
          assert.equal(testAvatar.toString(), result.toString();
          return done();
      });
});

请注意对 res.text 而不是 res.body 的引用——因为您没有指定 content-type header 对于 Controller 中的响应，Supertest 不做任何假设，只是将原始数据添加到响应中的 text 字段。例如，如果您将 res.set("content-type", "image/jpeg"); 放入 Controller 中，那么测试中的响应 body 将是一个包含图像字节的缓冲区。

当我想对请求的结果运行单独的测试时，我倾向于在 before 函数中执行请求本身，然后保存 body 和 statusCode 在闭包范围的变量中，就像你在这里开始做的那样。然后你可以运行单独的 it 测试状态代码，正文内容等。所以我的整个测试看起来像:

var assert = require('assert');
var path = require('path');
var server = require('supertest');
var fs = require('fs');

describe('try to download a user avatar', function() {
    var result, status;
    var testAvatarFd = path.resolve(__dirname, '..', 'fixtures', 'test.jpeg');

    // Create the user and make the request before running the actual tests.
    before(function(done) {
      // Create a test user
      User.create({
        avatarFd: testAvatarFd
      }).exec(function(err, testUser) {
        if (err) {return done(err);}

          // Then request the user avatar from the server
          server(sails.hooks.http.app)
          .get('/user/' + testUser.id + '/avatar')
          .end(function(err, res) {
              if (err) return done(err);
              // Save the result in our closure-scoped variables
              result = res.text;
              status = res.statusCode;
              return done();
          });
      });
    });

    // The status code test is now synchronous
    it('should return 200', function() {
      assert.equal(status, 200);
    });

    // As is the file test, since we're using `readFileSync`
    it('should return binary data stream', function() {
      var testAvatar = fs.readFileSync(testAvatarFd);
      assert.equal(testAvatar.toString(), result.toString());
    });
});