GrpcMock

Library for stubbing grpc in Ruby.

Installation

Add this line to your application's Gemfile:

gem 'grpc_mock'

And then execute:

$ bundle

Or install it yourself as:

$ gem install grpc_mock

Usage

If you use RSpec, add the following code to spec/spec_helper.rb:

require 'grpc_mock/rspec'

Examples

See definition of protocol buffers and gRPC generated code in spec/examples/hello

Stubbed request based on path and with the default response

GrpcMock.stub_request("/hello.hello/Hello").to_return(Hello::HelloResponse.new(msg: 'test'))

client = Hello::Hello::Stub.new('localhost:8000', :this_channel_is_insecure)
client.hello(Hello::HelloRequest.new(msg: 'hi')) # => Hello::HelloResponse.new(msg: 'test')

Stubbing requests based on path and request

GrpcMock.stub_request("/hello.hello/Hello").with(Hello::HelloRequest.new(msg: 'hi')).to_return(Hello::HelloResponse.new(msg: 'test'))

client = Hello::Hello::Stub.new('localhost:8000', :this_channel_is_insecure)
client.hello(Hello::HelloRequest.new(msg: 'hello')) # => send a request to server
client client.hello(Hello::HelloRequest.new(msg: 'hi'))    # => Hello::HelloResponse.new(msg: 'test') (without any requests to server)

Responding dynamically to the stubbed requests

GrpcMock.stub_request("/hello.hello/Hello").to_return do |req, call|
  Hello::HelloResponse.new(msg: "#{req.msg} too")
end

client = Hello::Hello::Stub.new('localhost:8000', :this_channel_is_insecure)
client.hello(Hello::HelloRequest.new(msg: 'hi'))    # => Hello::HelloResponse.new(msg: 'hi too')

Real requests to network can be allowed or disabled

client = Hello::Hello::Stub.new('localhost:8000', :this_channel_is_insecure)

GrpcMock.disable_net_connect!
client.hello(Hello::HelloRequest.new(msg: 'hello')) # => Raise NetConnectNotAllowedError error

GrpcMock.allow_net_connect!
Hello::Hello::Stub.new('localhost:8000', :this_channel_is_insecure) # => send a request to server

Raising errors

Exception declared by class

GrpcMock.stub_request("/hello.hello/Hello").to_raise(StandardError)

client = Hello::Hello::Stub.new('localhost:8000', :this_channel_is_insecure)
client.hello(Hello::HelloRequest.new(msg: 'hi')) # => Raise StandardError

or by exception instance

GrpcMock.stub_request("/hello.hello/Hello").to_raise(StandardError.new("Some error"))

or by string

GrpcMock.stub_request("/hello.hello/Hello").to_raise("Some error")

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/ganmacs/grpc_mock. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

License

The gem is available as open source under the terms of the MIT License.