我已经写了一些Rack-Middleware,现在我试图用Rspec进行测试.但是所有Rack-Middleware都是用“app”参数实例化的,它代表了Rails应用程序本身.你怎么在Rspec里嘲笑这个？
例如,
describe MyMiddleWare do
let(:app) { # How do I mock a Rails app object here? }
subject { MyMiddleWare.new(app: app) }
it 'should blah blah blah' do
# a bunch of tests go here
end
end
解决方法
您只需要世界上最简单的Rack应用程序：
let(:app) { lambda {|env| [200,{'Content-Type' => 'text/plain'},['OK']]} }
此外,您的中间件的构造函数应该会收到一个应用程序作为其第一个参数,而不是哈希值,因此应该读取：
subject { MyMiddleWare.new(app) }
尽管如此,您的测试很可能需要确定中间件对请求的影响.所以你可能会写一个稍微更复杂的机架应用程序来监视你的中间件.
class MockRackApp
attr_reader :request_body
def initialize
@request_headers = {}
end
def call(env)
@env = env
@request_body = env['rack.input'].read
[200,['OK']]
end
def [](key)
@env[key]
end
end
然后你可能想使用Rack :: MockRequest来实际发送请求.就像是：
describe MyMiddleWare do
let(:app) { MockRackApp.new }
subject { described_class.new(app) }
context "when called with a POST request" do
let(:request) { Rack::MockRequest.new(subject) }
before(:each) do
request.post("/some/path",input: post_data,'CONTENT_TYPE' => 'text/plain')
end
context "with some particular data" do
let(:post_data) { "String or IO post data" }
it "passes the request through unchanged" do
expect(app['CONTENT_TYPE']).to eq('text/plain')
expect(app['CONTENT_LENGTH'].to_i).to eq(post_data.length)
expect(app.request_body).to eq(post_data)
end
end
end
end