Rails:在模型规范中测试文件上传验证(Shrine )

Question

下面的代码在Rails 4.2应用程序中测试模型规范中的图像验证，该应用程序带有RSpec 3.5，神龛宝石用于文件上传。

我的问题是：

• 您能想出一种改进以下测试的方法吗?还是更好的测试这些验证的方法？
• 如何提高文件大小验证测试的速度？如果可能的话，我想测试它，而不必实际上传一个>10‘d文件。

文件上传设置的其他方面在控制器和特性规范中进行了测试，这与这个问题无关。

RSpec.describe ShareImage, :type => :model do
  describe "#image", :focus do
    let(:image_file) do
      # Could not get fixture_file_upload to work, but that's irrelevant
      Rack::Test::UploadedFile.new(File.join(
        ActionController::TestCase.fixture_path, 'files', filename))
    end
    let(:share_image) { FactoryGirl.build(:share_image, image: image_file) }
    before(:each) { share_image.valid? }

    context "with a valid image file" do
      let(:filename) { 'image-valid.jpg' }
      it "attaches the image to this record" do
        expect(share_image.image.metadata["filename"]).to eq filename
      end
    end

    context "with JPG extension and 'text/plain' media type" do
      let(:filename) { 'image-with-text-media-type.jpg' }
      it "is invalid" do
        expect(share_image.errors[:image].to_s).to include("invalid file type")
      end
    end

    # TODO: Refactor the following test (it takes ~50 seconds to run)
    context "with a >10mb image file" do
      let(:filename) { 'image-11mb.jpg' }
      it "is invalid" do
        expect(share_image.errors[:image].to_s).to include("too large")
      end
    end
  end
end

Answer 1

我建议您分别测试元数据提取和验证。您需要在实际的IOs中测试的元数据提取，但是对于验证测试，您可以使用所需的元数据分配缓存的文件，而这些元数据并不一定实际存在。

RSpec.describe ImageUploader do
  def uploaded_file(metadata = {})
    Shrine.uploaded_file(
      "id"       => "123",
      "storage"  => "cache",
      "metadata" => {"mime_type" => "image/jpeg", "size" => 100}.merge(metadata)
    )
  end

  let(:share_image) do
    FactoryGirl.build(:share_image, image: uploaded_file(metadata).to_json)
  end

  let(:metadata) { Hash.new }

  describe "validations" do
    before(:each) { share_image.valid? }

    context "when image is correct" do
      it "passes" do
        expect(share_image.errors).to be_empty
      end
    end

    context "when extension is correct but MIME types isn't" do
      let(:metadata) { Hash["filename" => "image.jpg", mime_type => "text/plain"] }

      it "fails" do
        expect(share_image.errors[:image].to_s).to include("isn't of allowed type")
      end
    end

    context "when file is larger than 10MB" do
      let(:metadata) { Hash["size" => 11 * 1024 * 1024] }

      it "fails" do
        expect(share_image.errors[:image].to_s).to include("too large")
      end
    end
  end
end

Answer 2

与其通过Rack::Test::UploadedFile路由上传，不如直接使用夹具或工厂或直接在测试中创建附件元数据记录。最终的结果应该是您有附件元数据(这是您上传文件时构造的)，它引用您的文件，而不必通过上传代码运行它。我不确定用神殿做这件事的具体细节，但是这种技术在像Paperclip这样的库中很好地工作。在神殿中，这将意味着直接构建一个引用您的文件的Shrine::UploadedFile记录。