WebMock::Twirp

Twirp support for WebMock. All our favorite http request stubbing for Twirp RPCs - message and error serialization done automatically.

Install

gem "webmock-twirp"

Example

require "webmock/twirp"

it "stubs twirp calls" do 
  stub_twirp_request

  client.my_rpc_method(request)
end

it "matches calls from specific twirp clients and rpc methods" do
  stub_twirp_request(MyTwirpClient, :optional_rpc_method)
end

# match parameters
stub_twirp_request.with(my_request_message: /^foo/)

# or use block mode
stub_twirp_request.with do |request|
  request # the Twirp request, aka. proto message, used to initiate the request
  request.my_request_message == "hello"
end

# stub responses
stub_twirp_request.and_return(return_message: "yo yo")
stub_twirp_request.and_return(404) # results in a Twirp::Error.not_found

# or use block mode
stub_twirp_request.and_return do |request|
  { response_message: "oh hi" } # will get properly packaged up
end

Usage

.with

stub_twirp_request.with allows you to only stub requests which match specific attributes. It accepts a hash or a Google::Protobuf::MessageExts instance. The hash supports constants, regexes, and rspec matchers.

stub_twirp_request.with(message: "hi")
stub_twirp_request.with(message: /^h/)
stub_twirp_request.with(message: include("i"))

expected_request = MyTwirpRequest.new(message: "hi")
stub_twirp_request.with(expected_request)

If you want even more control over the matching criteria, use the block mode. A Protobuf instance is passed into the block with the request's parameters.

stub_twirp_request.with do |request|
  request.message == "hi"
end

.to_return

stub_twirp_request.to_return allows you to specify a response, or use a default response. It can be a hash or Protobuf instance. To return an error, specify an error code, http status, or Twirp::Error.

stub_twirp_request.to_return # ie. `MyTwirpResponse.new`

stub_twirp_request.to_return(msg: "bye")

response = MyTwirpResponse.new(msg: "bye")
stub_twirp_request.to_return(response)

# errors
stub_twirp_request.to_return(:not_found)
stub_twirp_request.to_return(404)
stub_twirp_request.to_return(Twirp::Error.not_found("Nope"))

The block mode passes in the request Protobuf.

stub_twirp_request.to_return do |request|
  if request.message == "hi"
    { msg: "bye" }
  else
    :not_found
  end
end

RSpec

stub = stub_twirp_request
# ... make requests ...
expect(stub).to have_been_requested

For Twirp specific RSpec matchers, see rspec-twirp

Improved WebMock Errors

Before

> client = EchoClient.new("http://example.com/twirp")
...
> client.echo(msg: "Hi")
/lib/webmock/http_lib_adapters/net_http.rb:104:in `request': Real HTTP connections are disabled. Unregistered request: 
POST http://example.com/twirp/Echo/Echo with body ' (WebMock::NetConnectNotAllowedError)
Hi' with headers {'Accept'=>'*/*', 'Accept-Encoding'=>'gzip;q=1.0,deflate;q=0.6,identity;q=0.3', 'Content-Type'=>'application/protobuf', 'User-Agent'=>'Faraday v1.10.2'}

You can stub this request with the following snippet:

stub_request(:post, "http://example.com/twirp/Echo/Echo").
  with(
    body: "\n\x02Hi",
    headers: {
       'Accept'=>'*/*',
       'Accept-Encoding'=>'gzip;q=1.0,deflate;q=0.6,identity;q=0.3',
       'Content-Type'=>'application/protobuf',
       'User-Agent'=>'Faraday v1.10.2'
    }).
  to_return(status: 200, body: "", headers: {})

After

> require "webmock-twirp"
> client = EchoClient.new("http://example.com/twirp")
...
> client.echo(msg: "Hi")
/lib/webmock/http_lib_adapters/net_http.rb:104:in `request': Real Twirp connections are disabled. Unregistered request: 
EchoClient(http://example.com/twirp/Echo/Echo).echo(msg: "Hi") (WebMock::NetConnectNotAllowedError)

You can stub this request with the following snippet:

stub_twirp_request(:echo).with(
  msg: "Hi",
).to_return(...)

Contributing

Yes please :)

1. Fork it
2. Create your feature branch (git checkout -b my-feature)
3. Ensure the tests pass (bundle exec rspec)
4. Commit your changes (git commit -am 'awesome new feature')
5. Push your branch (git push origin my-feature)
6. Create a Pull Request