Add Ruby server interceptors

9 files changed, 678 insertions, 71 deletions

diff --git a/src/ruby/spec/channel_connection_spec.rb b/src/ruby/spec/channel_connection_spec.rb
index c76056606b..ce3e3b1c93 100644
--- a/src/ruby/spec/channel_connection_spec.rb
+++ b/src/ruby/spec/channel_connection_spec.rb
@@ -11,45 +11,12 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-
-require 'grpc'
+require 'spec_helper'
 require 'timeout'
 
 include Timeout
 include GRPC::Core
 
-# A test message
-class EchoMsg
-  def self.marshal(_o)
-    ''
-  end
-
-  def self.unmarshal(_o)
-    EchoMsg.new
-  end
-end
-
-# A test service with an echo implementation.
-class EchoService
-  include GRPC::GenericService
-  rpc :an_rpc, EchoMsg, EchoMsg
-  attr_reader :received_md
-
-  def initialize(**kw)
-    @trailing_metadata = kw
-    @received_md = []
-  end
-
-  def an_rpc(req, call)
-    GRPC.logger.info('echo service received a request')
-    call.output_metadata.update(@trailing_metadata)
-    @received_md << call.metadata unless call.metadata.nil?
-    req
-  end
-end
-
-EchoStub = EchoService.rpc_stub_class
-
 def start_server(port = 0)
   @srv = GRPC::RpcServer.new(pool_size: 1)
   server_port = @srv.add_http2_port("localhost:#{port}", :this_port_is_insecure)
diff --git a/src/ruby/spec/generic/active_call_spec.rb b/src/ruby/spec/generic/active_call_spec.rb
index a00df9236d..120acc35af 100644
--- a/src/ruby/spec/generic/active_call_spec.rb
+++ b/src/ruby/spec/generic/active_call_spec.rb
@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-require 'grpc'
+require 'spec_helper'
 
 include GRPC::Core::StatusCodes
 
@@ -82,6 +82,16 @@ describe GRPC::ActiveCall do
         end
       end
     end
+
+    describe '#interceptable' do
+      it 'exposes a fixed subset of the ActiveCall.methods' do
+        want = %w(deadline)
+        v = @client_call.interceptable
+        want.each do |w|
+          expect(v.methods.include?(w))
+        end
+      end
+    end
   end
 
   describe '#remote_send' do
@@ -609,9 +619,11 @@ describe GRPC::ActiveCall do
         msgs
       end
 
+      int_ctx = GRPC::InterceptionContext.new
+
       @server_thread = Thread.new do
         @server_call.run_server_bidi(
-          fake_gen_each_reply_with_no_call_param)
+          fake_gen_each_reply_with_no_call_param, int_ctx)
         @server_call.send_status(@server_status)
       end
     end
@@ -624,10 +636,11 @@ describe GRPC::ActiveCall do
         call_param.send_initial_metadata
         msgs
       end
+      int_ctx = GRPC::InterceptionContext.new
 
       @server_thread = Thread.new do
         @server_call.run_server_bidi(
-          fake_gen_each_reply_with_call_param)
+          fake_gen_each_reply_with_call_param, int_ctx)
         @server_call.send_status(@server_status)
       end
     end
diff --git a/src/ruby/spec/generic/client_interceptors_spec.rb b/src/ruby/spec/generic/client_interceptors_spec.rb
new file mode 100644
index 0000000000..f292715e4d
--- /dev/null
+++ b/src/ruby/spec/generic/client_interceptors_spec.rb
@@ -0,0 +1,153 @@
+# Copyright 2017 gRPC authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+require 'spec_helper'
+
+describe 'Client Interceptors' do
+  let(:interceptor) { TestClientInterceptor.new }
+  let(:interceptors_opts) { { interceptors: [interceptor] } }
+  let(:request) { EchoMsg.new }
+  let(:service) { EchoService }
+
+  before(:each) do
+    build_rpc_server
+  end
+
+  context 'when a client interceptor is added' do
+    context 'with a request/response call' do
+      it 'should be called', server: true do
+        expect(interceptor).to receive(:request_response)
+          .once.and_call_original
+
+        run_services_on_server(@server, services: [service]) do
+          stub = build_insecure_stub(EchoStub, opts: interceptors_opts)
+          expect_any_instance_of(GRPC::ActiveCall).to receive(:request_response)
+            .once.and_call_original
+          expect(stub.an_rpc(request)).to be_a(EchoMsg)
+        end
+      end
+
+      it 'can modify outgoing metadata', server: true do
+        expect(interceptor).to receive(:request_response)
+          .once.and_call_original
+
+        run_services_on_server(@server, services: [service]) do
+          stub = build_insecure_stub(EchoStub, opts: interceptors_opts)
+          expect_any_instance_of(GRPC::ActiveCall).to receive(:request_response)
+            .with(request, metadata: { 'foo' => 'bar_from_request_response' })
+            .once.and_call_original
+          expect(stub.an_rpc(request)).to be_a(EchoMsg)
+        end
+      end
+    end
+
+    context 'with a client streaming call' do
+      it 'should be called', server: true do
+        expect(interceptor).to receive(:client_streamer)
+          .once.and_call_original
+
+        run_services_on_server(@server, services: [service]) do
+          stub = build_insecure_stub(EchoStub, opts: interceptors_opts)
+          expect_any_instance_of(GRPC::ActiveCall).to receive(:client_streamer)
+            .once.and_call_original
+          requests = [EchoMsg.new, EchoMsg.new]
+          expect(stub.a_client_streaming_rpc(requests)).to be_a(EchoMsg)
+        end
+      end
+
+      it 'can modify outgoing metadata', server: true do
+        expect(interceptor).to receive(:client_streamer)
+          .once.and_call_original
+
+        run_services_on_server(@server, services: [service]) do
+          stub = build_insecure_stub(EchoStub, opts: interceptors_opts)
+          requests = [EchoMsg.new, EchoMsg.new]
+          expect_any_instance_of(GRPC::ActiveCall).to receive(:client_streamer)
+            .with(requests, metadata: { 'foo' => 'bar_from_client_streamer' })
+            .once.and_call_original
+          expect(stub.a_client_streaming_rpc(requests)).to be_a(EchoMsg)
+        end
+      end
+    end
+
+    context 'with a server streaming call' do
+      it 'should be called', server: true do
+        expect(interceptor).to receive(:server_streamer)
+          .once.and_call_original
+
+        run_services_on_server(@server, services: [service]) do
+          stub = build_insecure_stub(EchoStub, opts: interceptors_opts)
+          request = EchoMsg.new
+          expect_any_instance_of(GRPC::ActiveCall).to receive(:server_streamer)
+            .once.and_call_original
+          responses = stub.a_server_streaming_rpc(request)
+          responses.each do |r|
+            expect(r).to be_a(EchoMsg)
+          end
+        end
+      end
+
+      it 'can modify outgoing metadata', server: true do
+        expect(interceptor).to receive(:server_streamer)
+          .once.and_call_original
+
+        run_services_on_server(@server, services: [service]) do
+          stub = build_insecure_stub(EchoStub, opts: interceptors_opts)
+          request = EchoMsg.new
+          expect_any_instance_of(GRPC::ActiveCall).to receive(:server_streamer)
+            .with(request, metadata: { 'foo' => 'bar_from_server_streamer' })
+            .once.and_call_original
+          responses = stub.a_server_streaming_rpc(request)
+          responses.each do |r|
+            expect(r).to be_a(EchoMsg)
+          end
+        end
+      end
+    end
+
+    context 'with a bidi call' do
+      it 'should be called', server: true do
+        expect(interceptor).to receive(:bidi_streamer)
+          .once.and_call_original
+
+        run_services_on_server(@server, services: [service]) do
+          stub = build_insecure_stub(EchoStub, opts: interceptors_opts)
+          expect_any_instance_of(GRPC::ActiveCall).to receive(:bidi_streamer)
+            .once.and_call_original
+          requests = [EchoMsg.new, EchoMsg.new]
+          responses = stub.a_bidi_rpc(requests)
+          responses.each do |r|
+            expect(r).to be_a(EchoMsg)
+          end
+        end
+      end
+
+      it 'can modify outgoing metadata', server: true do
+        expect(interceptor).to receive(:bidi_streamer)
+          .once.and_call_original
+
+        run_services_on_server(@server, services: [service]) do
+          stub = build_insecure_stub(EchoStub, opts: interceptors_opts)
+          requests = [EchoMsg.new, EchoMsg.new]
+          expect_any_instance_of(GRPC::ActiveCall).to receive(:bidi_streamer)
+            .with(requests, metadata: { 'foo' => 'bar_from_bidi_streamer' })
+            .once.and_call_original
+          responses = stub.a_bidi_rpc(requests)
+          responses.each do |r|
+            expect(r).to be_a(EchoMsg)
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/src/ruby/spec/generic/interceptor_registry_spec.rb b/src/ruby/spec/generic/interceptor_registry_spec.rb
new file mode 100644
index 0000000000..f93f5cec09
--- /dev/null
+++ b/src/ruby/spec/generic/interceptor_registry_spec.rb
@@ -0,0 +1,65 @@
+# Copyright 2017 gRPC authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+require 'spec_helper'
+
+describe GRPC::InterceptorRegistry do
+  let(:server) { RpcServer.new }
+  let(:interceptor) { TestServerInterceptor.new }
+  let(:interceptors) { [interceptor] }
+  let(:registry) { described_class.new(interceptors) }
+
+  describe 'initialization' do
+    subject { registry }
+
+    context 'with an interceptor extending GRPC::ServerInterceptor' do
+      it 'should add the interceptor to the registry' do
+        subject
+        is = registry.instance_variable_get('@interceptors')
+        expect(is.count).to eq 1
+        expect(is.first).to eq interceptor
+      end
+    end
+
+    context 'with multiple interceptors' do
+      let(:interceptor2) { TestServerInterceptor.new }
+      let(:interceptor3) { TestServerInterceptor.new }
+      let(:interceptors) { [interceptor, interceptor2, interceptor3] }
+
+      it 'should maintain order of insertion when iterated against' do
+        subject
+        is = registry.instance_variable_get('@interceptors')
+        expect(is.count).to eq 3
+        is.each_with_index do |i, idx|
+          case idx
+          when 0
+            expect(i).to eq interceptor
+          when 1
+            expect(i).to eq interceptor2
+          when 2
+            expect(i).to eq interceptor3
+          end
+        end
+      end
+    end
+
+    context 'with an interceptor not extending GRPC::ServerInterceptor' do
+      let(:interceptor) { Class }
+      let(:err) { GRPC::InterceptorRegistry::DescendantError }
+
+      it 'should raise an InvalidArgument exception' do
+        expect { subject }.to raise_error(err)
+      end
+    end
+  end
+end
diff --git a/src/ruby/spec/generic/rpc_server_spec.rb b/src/ruby/spec/generic/rpc_server_spec.rb
index b887eaaf4e..05059fbecf 100644
--- a/src/ruby/spec/generic/rpc_server_spec.rb
+++ b/src/ruby/spec/generic/rpc_server_spec.rb
@@ -11,8 +11,7 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-
-require 'grpc'
+require 'spec_helper'
 
 def load_test_certs
   test_root = File.join(File.dirname(File.dirname(__FILE__)), 'testdata')
@@ -28,17 +27,6 @@ def check_md(wanted_md, received_md)
   end
 end
 
-# A test message
-class EchoMsg
-  def self.marshal(_o)
-    ''
-  end
-
-  def self.unmarshal(_o)
-    EchoMsg.new
-  end
-end
-
 # A test service with no methods.
 class EmptyService
   include GRPC::GenericService
@@ -50,27 +38,6 @@ class NoRpcImplementation
   rpc :an_rpc, EchoMsg, EchoMsg
 end
 
-# A test service with an echo implementation.
-class EchoService
-  include GRPC::GenericService
-  rpc :an_rpc, EchoMsg, EchoMsg
-  attr_reader :received_md
-
-  def initialize(**kw)
-    @trailing_metadata = kw
-    @received_md = []
-  end
-
-  def an_rpc(req, call)
-    GRPC.logger.info('echo service received a request')
-    call.output_metadata.update(@trailing_metadata)
-    @received_md << call.metadata unless call.metadata.nil?
-    req
-  end
-end
-
-EchoStub = EchoService.rpc_stub_class
-
 # A test service with an implementation that fails with BadStatus
 class FailingService
   include GRPC::GenericService
diff --git a/src/ruby/spec/generic/server_interceptors_spec.rb b/src/ruby/spec/generic/server_interceptors_spec.rb
new file mode 100644
index 0000000000..eb86686084
--- /dev/null
+++ b/src/ruby/spec/generic/server_interceptors_spec.rb
@@ -0,0 +1,218 @@
+# Copyright 2017 gRPC authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+require 'spec_helper'
+
+describe 'Server Interceptors' do
+  let(:interceptor) { TestServerInterceptor.new }
+  let(:request) { EchoMsg.new }
+  let(:trailing_metadata) { {} }
+  let(:service) { EchoService.new(trailing_metadata) }
+  let(:interceptors) { [] }
+
+  before(:each) do
+    build_rpc_server(server_opts: { interceptors: interceptors })
+  end
+
+  context 'when a server interceptor is added' do
+    let(:interceptors) { [interceptor] }
+    let(:client_metadata) { { client_md: 'test' } }
+    let(:client_call_opts) { { metadata: client_metadata, return_op: true } }
+
+    context 'with a request/response call' do
+      let(:trailing_metadata) { { server_om: 'from_request_response' } }
+
+      it 'should be called', server: true do
+        expect(interceptor).to receive(:request_response)
+          .once.and_call_original
+
+        run_services_on_server(@server, services: [service]) do
+          stub = build_insecure_stub(EchoStub)
+          expect(stub.an_rpc(request)).to be_a(EchoMsg)
+        end
+      end
+
+      it 'can modify trailing metadata', server: true do
+        expect(interceptor).to receive(:request_response)
+          .once.and_call_original
+
+        run_services_on_server(@server, services: [service]) do
+          stub = build_insecure_stub(EchoStub)
+          expect_any_instance_of(GRPC::ActiveCall).to(
+            receive(:request_response).with(request, metadata: client_metadata)
+              .once.and_call_original
+          )
+          op = stub.an_rpc(request, client_call_opts)
+          msg = op.execute
+          expect(op.trailing_metadata).to eq(
+            'interc' => 'from_request_response',
+            'server_om' => 'from_request_response'
+          )
+          expect(msg).to be_a(EchoMsg)
+        end
+      end
+    end
+
+    context 'with a client streaming call' do
+      let(:trailing_metadata) { { server_om: 'from_client_streamer' } }
+      let(:requests) { [EchoMsg.new, EchoMsg.new] }
+
+      it 'should be called', server: true do
+        expect(interceptor).to receive(:client_streamer)
+          .once.and_call_original
+
+        run_services_on_server(@server, services: [service]) do
+          stub = build_insecure_stub(EchoStub)
+          expect(stub.a_client_streaming_rpc(requests)).to be_a(EchoMsg)
+        end
+      end
+
+      it 'can modify trailing metadata', server: true do
+        expect(interceptor).to receive(:client_streamer)
+          .once.and_call_original
+
+        run_services_on_server(@server, services: [service]) do
+          stub = build_insecure_stub(EchoStub)
+          expect_any_instance_of(GRPC::ActiveCall).to(
+            receive(:client_streamer).with(requests)
+              .once.and_call_original
+          )
+          op = stub.a_client_streaming_rpc(requests, client_call_opts)
+          msg = op.execute
+          expect(op.trailing_metadata).to eq(
+            'interc' => 'from_client_streamer',
+            'server_om' => 'from_client_streamer'
+          )
+          expect(msg).to be_a(EchoMsg)
+        end
+      end
+    end
+
+    context 'with a server streaming call' do
+      let(:trailing_metadata) { { server_om: 'from_server_streamer' } }
+      let(:request) { EchoMsg.new }
+
+      it 'should be called', server: true do
+        expect(interceptor).to receive(:server_streamer)
+          .once.and_call_original
+
+        run_services_on_server(@server, services: [service]) do
+          stub = build_insecure_stub(EchoStub)
+          responses = stub.a_server_streaming_rpc(request)
+          responses.each do |r|
+            expect(r).to be_a(EchoMsg)
+          end
+        end
+      end
+
+      it 'can modify trailing metadata', server: true do
+        expect(interceptor).to receive(:server_streamer)
+          .once.and_call_original
+
+        run_services_on_server(@server, services: [service]) do
+          stub = build_insecure_stub(EchoStub)
+          expect_any_instance_of(GRPC::ActiveCall).to(
+            receive(:server_streamer).with(request)
+              .once.and_call_original
+          )
+          op = stub.a_server_streaming_rpc(request, client_call_opts)
+          responses = op.execute
+          responses.each do |r|
+            expect(r).to be_a(EchoMsg)
+          end
+          expect(op.trailing_metadata).to eq(
+            'interc' => 'from_server_streamer',
+            'server_om' => 'from_server_streamer'
+          )
+        end
+      end
+    end
+
+    context 'with a bidi call' do
+      let(:trailing_metadata) { { server_om: 'from_bidi_streamer' } }
+      let(:requests) { [EchoMsg.new, EchoMsg.new] }
+
+      it 'should be called', server: true do
+        expect(interceptor).to receive(:bidi_streamer)
+          .once.and_call_original
+
+        run_services_on_server(@server, services: [service]) do
+          stub = build_insecure_stub(EchoStub)
+          responses = stub.a_bidi_rpc(requests)
+          responses.each do |r|
+            expect(r).to be_a(EchoMsg)
+          end
+        end
+      end
+
+      it 'can modify trailing metadata', server: true do
+        expect(interceptor).to receive(:bidi_streamer)
+          .once.and_call_original
+
+        run_services_on_server(@server, services: [service]) do
+          stub = build_insecure_stub(EchoStub)
+          expect_any_instance_of(GRPC::ActiveCall).to(
+            receive(:bidi_streamer).with(requests)
+              .once.and_call_original
+          )
+          op = stub.a_bidi_rpc(requests, client_call_opts)
+          responses = op.execute
+          responses.each do |r|
+            expect(r).to be_a(EchoMsg)
+          end
+          expect(op.trailing_metadata).to eq(
+            'interc' => 'from_bidi_streamer',
+            'server_om' => 'from_bidi_streamer'
+          )
+        end
+      end
+    end
+  end
+
+  context 'when multiple interceptors are added' do
+    let(:interceptor2) { TestServerInterceptor.new }
+    let(:interceptor3) { TestServerInterceptor.new }
+    let(:interceptors) do
+      [
+        interceptor,
+        interceptor2,
+        interceptor3
+      ]
+    end
+
+    it 'each should be called', server: true do
+      expect(interceptor).to receive(:request_response)
+        .once.and_call_original
+      expect(interceptor2).to receive(:request_response)
+        .once.and_call_original
+      expect(interceptor3).to receive(:request_response)
+        .once.and_call_original
+
+      run_services_on_server(@server, services: [service]) do
+        stub = build_insecure_stub(EchoStub)
+        expect(stub.an_rpc(request)).to be_a(EchoMsg)
+      end
+    end
+  end
+
+  context 'when an interceptor is not added' do
+    it 'should not be called', server: true do
+      expect(interceptor).to_not receive(:call)
+
+      run_services_on_server(@server, services: [service]) do
+        stub = build_insecure_stub(EchoStub)
+        expect(stub.an_rpc(request)).to be_a(EchoMsg)
+      end
+    end
+  end
+end
diff --git a/src/ruby/spec/spec_helper.rb b/src/ruby/spec/spec_helper.rb
index 6e1eba1945..8fe9e6e808 100644
--- a/src/ruby/spec/spec_helper.rb
+++ b/src/ruby/spec/spec_helper.rb
@@ -32,6 +32,9 @@ require 'rspec'
 require 'logging'
 require 'rspec/logging_helper'
 
+require_relative 'support/services'
+require_relative 'support/helpers'
+
 # GRPC is the general RPC module
 #
 # Configure its logging for fine-grained log control during test runs
@@ -49,6 +52,7 @@ Logging.logger['GRPC::BidiCall'].level = :info
 RSpec.configure do |config|
   include RSpec::LoggingHelper
   config.capture_log_messages  # comment this out to see logs during test runs
+  include GRPC::Spec::Helpers
 end
 
 RSpec::Expectations.configuration.warn_about_potential_false_positives = false
diff --git a/src/ruby/spec/support/helpers.rb b/src/ruby/spec/support/helpers.rb
new file mode 100644
index 0000000000..65fffff9e7
--- /dev/null
+++ b/src/ruby/spec/support/helpers.rb
@@ -0,0 +1,73 @@
+# Copyright 2017 gRPC authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# GRPC contains the General RPC module.
+module GRPC
+  ##
+  # GRPC RSpec base module
+  #
+  module Spec
+    ##
+    # A module that is used for providing generic helpers across the
+    # GRPC test suite
+    #
+    module Helpers
+      # Shortcut syntax for a GRPC RPC Server
+      RpcServer = GRPC::RpcServer
+
+      ##
+      # Build an RPC server used for testing
+      #
+      def build_rpc_server(server_opts: {},
+                           client_opts: {})
+        @server = RpcServer.new({ poll_period: 1 }.merge(server_opts))
+        @port = @server.add_http2_port('0.0.0.0:0', :this_port_is_insecure)
+        @host = "0.0.0.0:#{@port}"
+        @client_opts = client_opts
+        @server
+      end
+
+      ##
+      # Run services on an RPC server, yielding to allow testing within
+      #
+      # @param [RpcServer] server
+      # @param [Array<Class>] services
+      #
+      def run_services_on_server(server, services: [])
+        services.each do |s|
+          server.handle(s)
+        end
+        t = Thread.new { server.run }
+        server.wait_till_running
+
+        yield
+
+        server.stop
+        t.join
+      end
+
+      ##
+      # Build an insecure stub from a given stub class
+      #
+      # @param [Class] klass
+      # @param [String] host
+      #
+      def build_insecure_stub(klass, host: nil, opts: nil)
+        host ||= @host
+        opts ||= @client_opts
+        klass.new(host, :this_channel_is_insecure, **opts)
+      end
+    end
+  end
+end
diff --git a/src/ruby/spec/support/services.rb b/src/ruby/spec/support/services.rb
new file mode 100644
index 0000000000..27cc8e61ac
--- /dev/null
+++ b/src/ruby/spec/support/services.rb
@@ -0,0 +1,147 @@
+# Copyright 2017 gRPC authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# Test stubs for various scenarios
+require 'grpc'
+
+# A test message
+class EchoMsg
+  def self.marshal(_o)
+    ''
+  end
+
+  def self.unmarshal(_o)
+    EchoMsg.new
+  end
+end
+
+# A test service with an echo implementation.
+class EchoService
+  include GRPC::GenericService
+  rpc :an_rpc, EchoMsg, EchoMsg
+  rpc :a_client_streaming_rpc, stream(EchoMsg), EchoMsg
+  rpc :a_server_streaming_rpc, EchoMsg, stream(EchoMsg)
+  rpc :a_bidi_rpc, stream(EchoMsg), stream(EchoMsg)
+  attr_reader :received_md
+
+  def initialize(**kw)
+    @trailing_metadata = kw
+    @received_md = []
+  end
+
+  def an_rpc(req, call)
+    GRPC.logger.info('echo service received a request')
+    call.output_metadata.update(@trailing_metadata)
+    @received_md << call.metadata unless call.metadata.nil?
+    req
+  end
+
+  def a_client_streaming_rpc(call)
+    # iterate through requests so call can complete
+    call.output_metadata.update(@trailing_metadata)
+    call.each_remote_read.each { |r| p r }
+    EchoMsg.new
+  end
+
+  def a_server_streaming_rpc(_req, call)
+    call.output_metadata.update(@trailing_metadata)
+    [EchoMsg.new, EchoMsg.new]
+  end
+
+  def a_bidi_rpc(requests, call)
+    call.output_metadata.update(@trailing_metadata)
+    requests.each { |r| p r }
+    [EchoMsg.new, EchoMsg.new]
+  end
+end
+
+EchoStub = EchoService.rpc_stub_class
+
+# For testing server interceptors
+class TestServerInterceptor < GRPC::ServerInterceptor
+  def request_response(request:, call:, method:)
+    p "Received request/response call at method #{method}" \
+      " with request #{request} for call #{call}"
+    call.output_metadata[:interc] = 'from_request_response'
+    p "[GRPC::Ok] (#{method.owner.name}.#{method.name})"
+    yield
+  end
+
+  def client_streamer(call:, method:)
+    call.output_metadata[:interc] = 'from_client_streamer'
+    call.each_remote_read.each do |r|
+      p "In interceptor: #{r}"
+    end
+    p "Received client streamer call at method #{method} for call #{call}"
+    yield
+  end
+
+  def server_streamer(request:, call:, method:)
+    p "Received server streamer call at method #{method} with request" \
+      " #{request} for call #{call}"
+    call.output_metadata[:interc] = 'from_server_streamer'
+    yield
+  end
+
+  def bidi_streamer(requests:, call:, method:)
+    requests.each do |r|
+      p "Bidi request: #{r}"
+    end
+    p "Received bidi streamer call at method #{method} with requests" \
+      " #{requests} for call #{call}"
+    call.output_metadata[:interc] = 'from_bidi_streamer'
+    yield
+  end
+end
+
+# For testing client interceptors
+class TestClientInterceptor < GRPC::ClientInterceptor
+  def request_response(request:, call:, method:, metadata: {})
+    p "Intercepted request/response call at method #{method}" \
+      " with request #{request} for call #{call}" \
+      " and metadata: #{metadata}"
+    metadata['foo'] = 'bar_from_request_response'
+    yield
+  end
+
+  def client_streamer(requests:, call:, method:, metadata: {})
+    p "Received client streamer call at method #{method}" \
+      " with requests #{requests} for call #{call}" \
+      " and metadata: #{metadata}"
+    requests.each do |r|
+      p "In client interceptor: #{r}"
+    end
+    metadata['foo'] = 'bar_from_client_streamer'
+    yield
+  end
+
+  def server_streamer(request:, call:, method:, metadata: {})
+    p "Received server streamer call at method #{method}" \
+      " with request #{request} for call #{call}" \
+      " and metadata: #{metadata}"
+    metadata['foo'] = 'bar_from_server_streamer'
+    yield
+  end
+
+  def bidi_streamer(requests:, call:, method:, metadata: {})
+    p "Received bidi streamer call at method #{method}" \
+      "with requests #{requests} for call #{call}" \
+      " and metadata: #{metadata}"
+    requests.each do |r|
+      p "In client interceptor: #{r}"
+    end
+    metadata['foo'] = 'bar_from_bidi_streamer'
+    yield
+  end
+end