add JSONRPC error code to Client::RpcError (#392)

Author: achernik

lib/eth/client.rb

@@ -40,25 +40,28 @@ class Client
     # A custom error type if a contract interaction fails.
     class ContractExecutionError < StandardError; end
 
-    # Raised when an RPC call returns an error. Carries the optional
+    # Raised when an RPC call returns an error. Carries the error code and the optional
     # hex-encoded error data to support custom error decoding.
     class RpcError < IOError
       attr_reader :data
+      attr_reader :code
 
       # Constructor for the {RpcError} class.
       #
       # @param message [String] the error message returned by the RPC.
       # @param data [String] optional hex encoded error data.
-      def initialize(message, data = nil)
+      # @param code [String] optional error code returned by the RPC.
+      def initialize(message, data = nil, code = nil)
         super(message)
         @data = data
+        @code = code
       end
     end
 
     # Creates a new RPC-Client, either by providing an HTTP/S host, WS/S host,
     # or an IPC path. Supports basic authentication with username and password.
     #
-    # **Note**, this sets the folling gas defaults: {Tx::DEFAULT_PRIORITY_FEE}
+    # **Note**, this sets the following gas defaults: {Tx::DEFAULT_PRIORITY_FEE}
     # and {Tx::DEFAULT_GAS_PRICE. Use {#max_priority_fee_per_gas} and
     # {#max_fee_per_gas} to set custom values prior to submitting transactions.
     #
@@ -483,7 +486,7 @@ def send_command(command, args)
       }
       output = JSON.parse(send_request(payload.to_json))
       if (err = output["error"])
-        raise RpcError.new(err["message"], err["data"])
+        raise RpcError.new(err["message"], err["data"], err["code"])
       end
       output
     end

spec/eth/client_spec.rb

@@ -2,8 +2,8 @@
 
 describe Client do
 
-  # run `geth --dev --http --ipcpath /tmp/geth.ipc`
-  # to provide both http and ipc to pass these tests.
+  # run `geth --dev --http --wc --ipcpath /tmp/geth.ipc`
+  # to provide http, ws and ipc to pass these tests.
   let(:geth_ipc_path) { "/tmp/geth.ipc" }
   let(:geth_http_path) { "http://127.0.0.1:8545" }
   let(:geth_ws_path) { "ws://127.0.0.1:8546" }
@@ -121,6 +121,20 @@
     end
   end
 
+  describe Client::RpcError do
+    %i[http ws].each do |protocol|
+      context "when #{protocol}" do
+        it "carries the JSONRPC message and code returned by the server" do
+          client = send("geth_#{protocol}")
+
+          expect { client.get_balance("0xinvalid") }.to(
+            raise_error(an_instance_of(Client::RpcError).and have_attributes(message: /invalid argument 0:/, code: -32602))
+          )
+        end
+      end
+    end
+  end
+
   describe ".transfer .transfer_and_wait" do
     subject(:test_key) { Key.new }
     subject(:another_key) { Key.new }