Custom error type to wrap around Beefcake errors.

Change-Id: Id724690e9a86b55dd8f7ed58321bd2cf397e1ede

warden-protocol/lib/warden/protocol/base.rb

@@ -94,6 +94,19 @@ def self.to_response_klass(type)
       :string   => lambda { |arg| String(arg) },
     }
 
+    # Used to wrap around Beefcake errors.
+    class ProtocolError < StandardError
+      attr_reader :cause
+
+      def initialize(cause)
+        @cause = cause
+      end
+
+      def message
+        return @cause.message
+      end
+    end
+
     def self.protocol_type_to_str(protocol_type)
       if protocol_type.class == Module
         return "#{protocol_type.constants.join(", ")}"
@@ -121,8 +134,16 @@ def self.to_ruby_type(str, protocol_type)
     class BaseMessage
       include Beefcake::Message
 
+      def safe
+          yield
+        rescue WrongTypeError, InvalidValueError, RequiredFieldNotSetError => e
+          raise ProtocolError, e
+      end
+
       def reload
-        self.class.decode(encode)
+        safe do
+          self.class.decode(encode)
+        end
       end
 
       class << self
@@ -155,7 +176,9 @@ def create_response(attributes = {})
       end
 
       def wrap
-        WrappedRequest.new(:type => self.class.type, :payload => encode)
+        safe do
+          WrappedRequest.new(:type => self.class.type, :payload => encode)
+        end
       end
 
       def self.description
@@ -173,7 +196,9 @@ def error?
       end
 
       def wrap
-        WrappedResponse.new(:type => self.class.type, :payload => encode)
+        safe do
+          WrappedResponse.new(:type => self.class.type, :payload => encode)
+        end
       end
     end
 
@@ -182,7 +207,9 @@ class WrappedRequest < BaseRequest
       required :payload, :string, 2
 
       def request
-        Type.to_request_klass(type).decode(payload)
+        safe do
+          Type.to_request_klass(type).decode(payload)
+        end
       end
     end
 
@@ -191,7 +218,9 @@ class WrappedResponse < BaseResponse
       required :payload, :string, 2
 
       def response
-        Type.to_response_klass(type).decode(payload)
+        safe do
+          Type.to_response_klass(type).decode(payload)
+        end
       end
     end
   end

warden-protocol/lib/warden/protocol/version.rb

@@ -2,6 +2,6 @@
 
 module Warden
   module Protocol
-    VERSION = "0.0.8"
+    VERSION = "0.0.9"
   end
 end

warden-protocol/spec/base_spec.rb

@@ -3,6 +3,46 @@
 require "spec_helper"
 require "warden/protocol"
 
+describe Warden::Protocol::BaseRequest do
+  it "should respond to #wrap" do
+    request = Warden::Protocol::SpawnRequest.new(:handle => "blah",
+                                                 :script => "script")
+    wrapped = request.wrap
+    wrapped.should be_an_instance_of(Warden::Protocol::WrappedRequest)
+    wrapped.type.should == Warden::Protocol::SpawnRequest.type
+    decoded = Warden::Protocol::SpawnRequest.decode(wrapped.payload)
+    decoded.handle.should == request.handle
+    decoded.script.should == request.script
+  end
+
+  it "should wrap beefcake errors" do
+    expect {
+      Warden::Protocol::SpawnRequest.new.wrap
+    }.to raise_error(Warden::Protocol::ProtocolError) { |e|
+      e.cause.class.name.should =~ /^Beefcake/
+    }
+  end
+end
+
+describe Warden::Protocol::BaseResponse do
+  it "should respond to #wrap" do
+    response = Warden::Protocol::SpawnResponse.new(:job_id => 1)
+    wrapped = response.wrap
+    wrapped.should be_an_instance_of(Warden::Protocol::WrappedResponse)
+    wrapped.type.should == Warden::Protocol::SpawnResponse.type
+    decoded = Warden::Protocol::SpawnResponse.decode(wrapped.payload)
+    decoded.job_id.should == response.job_id
+  end
+
+  it "should wrap beefcake errors" do
+    expect {
+      Warden::Protocol::SpawnResponse.new.wrap
+    }.to raise_error(Warden::Protocol::ProtocolError) { |e|
+      e.cause.class.name.should =~ /^Beefcake/
+    }
+  end
+end
+
 describe Warden::Protocol::WrappedRequest do
   it "should respond to #request" do
     w = Warden::Protocol::WrappedRequest.new
@@ -13,6 +53,15 @@
 
     w.request.should be_a(Warden::Protocol::SpawnRequest)
   end
+
+  it "should wrap beefcake errors" do
+    w = Warden::Protocol::WrappedRequest.new
+    w.type = Warden::Protocol::Type::Spawn
+    w.payload = "bad payload"
+    w.should be_valid
+
+    expect { w.request }.to raise_error(Warden::Protocol::ProtocolError)
+  end
 end
 
 describe Warden::Protocol::WrappedResponse do
@@ -25,6 +74,16 @@
 
     w.response.should be_a(Warden::Protocol::SpawnResponse)
   end
+
+  it "should wrap beefcake errors" do
+    w = Warden::Protocol::WrappedResponse.new
+    w.type = Warden::Protocol::Type::Spawn
+    w.payload = "bad payload"
+
+    w.should be_valid
+
+    expect { w.response }.to raise_error(Warden::Protocol::ProtocolError)
+  end
 end
 
 describe Warden::Protocol do