Rails 5 rspec 测试失败，用于上传的文件存根

Question

在我的上传文件的 rspec 中，我正在存根这样的函数：

 allow(ABCCLass::XYZProcessor).to receive(:prepare_processing).with(csv_statements).and_return(nil)

和

let(:csv_statements) do
 [fixture_file_upload('transaction.csv', 'application/csv')]
end

我在预期中出现错误：预期机架：：测试：：上传文件got ActionDispatch：：Http：：UploadedFile

这是完全有意义的，因为fixture_file_upload返回机架：：测试：：上传文件并用它生成存根，但在控制器上传文件中是操作：:D ispatch：：上传文件的实例。

知道如何创建存根并解决此问题吗？

回溯：

-[[#<Rack::Test::UploadedFile:0x00559d3f298100 @content_type="application/csv", @original_filename="blank.csv", @tempfile=#<Tempfile:/tmp/blank.csv20180114-293-jcb2ii>, @_filename="eur-transactions.csv">,
   -  #<Rack::Test::UploadedFile:0x00559d3f296e40 @content_type="application/csv", @original_filename="blank.csv", @tempfile=#<Tempfile:/tmp/blank.csv20180114-293-1xbpd0t>, @_filename="gbp-statement.csv">,
   -  #<Rack::Test::UploadedFile:0x00559d3f295e50 @content_type="application/csv", @original_filename="blank.csv", @tempfile=#<Tempfile:/tmp/blank.csv20180114-293-1peng22>, @_filename="internal_HSBCnet1.xls">]]
   +[[#<ActionDispatch::Http::UploadedFile:0x00559d3cb3a6a8 @tempfile=#<Tempfile:/tmp/RackMultipart20180114-293-1l9ma69.csv>, @original_filename="eur-transactions.csv", @content_type="application/csv", @headers="Content-Disposition: form-data; name="bank_statements[]"; filename="eur-transactions.csv"rnContent-Type: application/csvrnContent-Length: 0rn">,
   +  #<ActionDispatch::Http::UploadedFile:0x00559d3cb3a608 @tempfile=#<Tempfile:/tmp/RackMultipart20180114-293-17oxrrk.csv>, @original_filename="gbp-statement.csv", @content_type="application/csv", @headers="Content-Disposition: form-data; name="bank_statements[]"; filename="gbp-statement.csv"rnContent-Type: application/csvrnContent-Length: 0rn">,
   +  #<ActionDispatch::Http::UploadedFile:0x00559d3cb3a568 @tempfile=#<Tempfile:/tmp/RackMultipart20180114-293-2ukuul.xls>, @original_filename="internal_HSBCnet1.xls", @content_type="application/csv", @headers="Content-Disposition: form-data; name="bank_statements[]"; filename="internal_HSBCnet1.xls"rnContent-Type: application/csvrnContent-Length: 0rn">]]
    Please stub a default value first if message might be received with other args as well. 
 # /root/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/rspec-support-3.7.0/lib/rspec/support.rb:97:in `block in <module:Support>'
 # /root/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/rspec-support-3.7.0/lib/rspec/support.rb:106:in `call'
 # /root/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/rspec-support-3.7.0/lib/rspec/support.rb:106:in `notify_failure'
 # /root/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/rspec-mocks-3.7.0/lib/rspec/mocks/error_generator.rb:327:in `notify'
 # /root/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/rspec-mocks-3.7.0/lib/rspec/mocks/error_generator.rb:311:in `__raise'
 # /root/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/rspec-mocks-3.7.0/lib/rspec/mocks/error_generator.rb:60:in `raise_missing_default_stub_error'
 # /root/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/rspec-mocks-3.7.0/lib/rspec/mocks/proxy.rb:206:in `raise_missing_default_stub_error'
 # /root/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/rspec-mocks-3.7.0/lib/rspec/mocks/proxy.rb:191:in `message_received'
 # /root/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/rspec-mocks-3.7.0/lib/rspec/mocks/proxy.rb:326:in `message_received'
 # /root/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/rspec-mocks-3.7.0/lib/rspec/mocks/method_double.rb:77:in `proxy_method_invoked'
 # /root/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/rspec-mocks-3.7.0/lib/rspec/mocks/method_double.rb:64:in `block (2 levels) in define_proxy_method'
 # ./app/controllers/admin/daily_adjustments/bank_transfer_deposits_controller.rb:25:in `start_process'

Answer 1

一个老问题，但是我最近遇到了这个问题，我正在测试正确的参数是否被传递给另一个类，包括上传的 csv 文件。

解决方法是存根ActionDispatch::Http::UploadedFile并使其:new方法返回fixture_file_upload创建的Rack::Test::UploadedFile:实例。

let(:csv_file) do
  path = Rails.root.join('spec', 'fixtures', 'test.csv')
  fixture_file_upload(path, 'text/csv')
end
before do
  allow(ActionDispatch::Http::UploadedFile).to receive(:new)
    .and_return(csv_file)
end
it 'passes csv file to class' do
  perform
  expect(MyClass).to have_received(:new).once.with(file: csv_file)
end

Answer 2

与其在测试中调用fixture_file_upload('transaction.csv', 'application/csv')，不如改为放置该返回值。

如果您想存根，我会使用实例双精度。像这样：

let(:csv_statements) { instance_double(Rack::Test::UploadedFile, content_type: 'application/csv', original_filename: 'blank.csv', file_name: 'eur-transactions.csv') }

这可能通过复制和粘贴不起作用，但这将存根该类的实例，并且每当收到这些消息时，它都会返回这些值。我不知道"fixture_file_upload"内部发生了什么，但是无论返回什么 Rack：：Test：：UploadedFile 对象，只需像这样存根即可。如果你想做一个类存根，它非常相似：

let(:csv_statements) { class_double(Rack::Test::UploadedFile, content_type: 'application/csv', original_filename: 'blank.csv', file_name: 'eur-transactions.csv').as_stubbed_const }

Answer 3

解决方案是使用 ActionDispatch::Http::UploadedFile 生成存根，因为目的是匹配实际函数的签名和参数。