Convert to proper errors

Allow returning different JSON RPC error codes depending on error type

rpc/api.go

@@ -578,7 +578,7 @@ func (p *EthereumApi) GetRequestReply(req *RpcRequest, reply *interface{}) error
 		}
 		return p.Call(args, reply)
 	case "eth_flush":
-		return errNotImplemented
+		return NewNotImplementedError(req.Method)
 	case "eth_getBlockByHash":
 		args := new(GetBlockByHashArgs)
 		if err := json.Unmarshal(req.Params, &args); err != nil {
@@ -618,7 +618,7 @@ func (p *EthereumApi) GetRequestReply(req *RpcRequest, reply *interface{}) error
 			return err
 		}
 		if args.Index > int64(len(v.Transactions)) || args.Index < 0 {
-			return NewErrorWithMessage(errDecodeArgs, "Transaction index does not exist")
+			return NewValidationError("Index", "does not exist")
 		}
 		*reply = v.Transactions[args.Index]
 	case "eth_getTransactionByBlockNumberAndIndex":
@@ -632,7 +632,7 @@ func (p *EthereumApi) GetRequestReply(req *RpcRequest, reply *interface{}) error
 			return err
 		}
 		if args.Index > int64(len(v.Transactions)) || args.Index < 0 {
-			return NewErrorWithMessage(errDecodeArgs, "Transaction index does not exist")
+			return NewValidationError("Index", "does not exist")
 		}
 		*reply = v.Transactions[args.Index]
 	case "eth_getUncleByBlockHashAndIndex":
@@ -646,7 +646,7 @@ func (p *EthereumApi) GetRequestReply(req *RpcRequest, reply *interface{}) error
 			return err
 		}
 		if args.Index > int64(len(v.Uncles)) || args.Index < 0 {
-			return NewErrorWithMessage(errDecodeArgs, "Uncle index does not exist")
+			return NewValidationError("Index", "does not exist")
 		}
 
 		uncle, err := p.GetBlockByHash(toHex(v.Uncles[args.Index]), false)
@@ -665,7 +665,7 @@ func (p *EthereumApi) GetRequestReply(req *RpcRequest, reply *interface{}) error
 			return err
 		}
 		if args.Index > int64(len(v.Uncles)) || args.Index < 0 {
-			return NewErrorWithMessage(errDecodeArgs, "Uncle index does not exist")
+			return NewValidationError("Index", "does not exist")
 		}
 
 		uncle, err := p.GetBlockByHash(toHex(v.Uncles[args.Index]), false)
@@ -678,7 +678,7 @@ func (p *EthereumApi) GetRequestReply(req *RpcRequest, reply *interface{}) error
 	case "eth_compileSolidity":
 	case "eth_compileLLL":
 	case "eth_compileSerpent":
-		return errNotImplemented
+		return NewNotImplementedError(req.Method)
 	case "eth_newFilter":
 		args := new(FilterOptions)
 		if err := json.Unmarshal(req.Params, &args); err != nil {
@@ -717,7 +717,7 @@ func (p *EthereumApi) GetRequestReply(req *RpcRequest, reply *interface{}) error
 		return p.AllLogs(args, reply)
 	case "eth_getWork":
 	case "eth_submitWork":
-		return errNotImplemented
+		return NewNotImplementedError(req.Method)
 	case "db_put":
 		args := new(DbArgs)
 		if err := json.Unmarshal(req.Params, &args); err != nil {
@@ -746,7 +746,7 @@ func (p *EthereumApi) GetRequestReply(req *RpcRequest, reply *interface{}) error
 		return p.HasWhisperIdentity(args.Identity, reply)
 	case "shh_newGroup":
 	case "shh_addToGroup":
-		return errNotImplemented
+		return NewNotImplementedError(req.Method)
 	case "shh_newFilter":
 		args := new(WhisperFilterArgs)
 		if err := json.Unmarshal(req.Params, &args); err != nil {
@@ -790,7 +790,7 @@ func (p *EthereumApi) GetRequestReply(req *RpcRequest, reply *interface{}) error
 	// 	}
 	// 	return p.WatchTx(args, reply)
 	default:
-		return NewErrorWithMessage(errNotImplemented, req.Method)
+		return NewNotImplementedError(req.Method)
 	}
 
 	rpclogger.DebugDetailf("Reply: %T %s", reply, reply)

rpc/http.go

@@ -25,22 +25,51 @@ func JSONRPC(pipe *xeth.XEth, dataDir string) http.Handler {
 		rpchttplogger.DebugDetailln("Handling request")
 
 		if req.ContentLength > maxSizeReqLength {
-			jsonerr := &RpcErrorObject{-32700, "Error: Request too large"}
+			jsonerr := &RpcErrorObject{-32700, "Request too large"}
 			json.Send(w, &RpcErrorResponse{JsonRpc: jsonrpcver, ID: nil, Error: jsonerr})
 			return
 		}
 
 		reqParsed, reqerr := json.ParseRequestBody(req)
-		if reqerr != nil {
-			jsonerr := &RpcErrorObject{-32700, "Error: Could not parse request"}
+		switch reqerr.(type) {
+		case nil:
+			break
+		case *DecodeParamError:
+			jsonerr := &RpcErrorObject{-32602, reqerr.Error()}
+			json.Send(w, &RpcErrorResponse{JsonRpc: jsonrpcver, ID: nil, Error: jsonerr})
+			return
+		case *InsufficientParamsError:
+			jsonerr := &RpcErrorObject{-32602, reqerr.Error()}
+			json.Send(w, &RpcErrorResponse{JsonRpc: jsonrpcver, ID: nil, Error: jsonerr})
+			return
+		case *ValidationError:
+			jsonerr := &RpcErrorObject{-32602, reqerr.Error()}
+			json.Send(w, &RpcErrorResponse{JsonRpc: jsonrpcver, ID: nil, Error: jsonerr})
+			return
+		default:
+			jsonerr := &RpcErrorObject{-32700, "Could not parse request"}
 			json.Send(w, &RpcErrorResponse{JsonRpc: jsonrpcver, ID: nil, Error: jsonerr})
 			return
 		}
 
 		var response interface{}
 		reserr := api.GetRequestReply(&reqParsed, &response)
-		if reserr != nil {
-			rpchttplogger.Warnln(reserr)
+		switch reserr.(type) {
+		case nil:
+			break
+		case *NotImplementedError:
+			jsonerr := &RpcErrorObject{-32601, reserr.Error()}
+			json.Send(w, &RpcErrorResponse{JsonRpc: jsonrpcver, ID: reqParsed.ID, Error: jsonerr})
+			return
+		case *InsufficientParamsError:
+			jsonerr := &RpcErrorObject{-32602, reserr.Error()}
+			json.Send(w, &RpcErrorResponse{JsonRpc: jsonrpcver, ID: reqParsed.ID, Error: jsonerr})
+			return
+		case *ValidationError:
+			jsonerr := &RpcErrorObject{-32602, reserr.Error()}
+			json.Send(w, &RpcErrorResponse{JsonRpc: jsonrpcver, ID: reqParsed.ID, Error: jsonerr})
+			return
+		default:
 			jsonerr := &RpcErrorObject{-32603, reserr.Error()}
 			json.Send(w, &RpcErrorResponse{JsonRpc: jsonrpcver, ID: reqParsed.ID, Error: jsonerr})
 			return

rpc/messages.go

@@ -18,16 +18,69 @@ package rpc
 
 import (
 	"encoding/json"
-	"errors"
 	"fmt"
 )
 
-var (
-	errArguments      = errors.New("Error: Insufficient arguments")
-	errNotImplemented = errors.New("Error: Method not implemented")
-	errUnknown        = errors.New("Error: Unknown error")
-	errDecodeArgs     = errors.New("Error: Could not decode arguments")
-)
+type InsufficientParamsError struct {
+	have int
+	want int
+}
+
+func (e *InsufficientParamsError) Error() string {
+	return fmt.Sprintf("insufficient params, want %d have %d", e.want, e.have)
+}
+
+func NewInsufficientParamsError(have int, want int) *InsufficientParamsError {
+	return &InsufficientParamsError{
+		have: have,
+		want: want,
+	}
+}
+
+type NotImplementedError struct {
+	Method string
+}
+
+func (e *NotImplementedError) Error() string {
+	return fmt.Sprintf("%s method not implemented", e.Method)
+}
+
+func NewNotImplementedError(method string) *NotImplementedError {
+	return &NotImplementedError{
+		Method: method,
+	}
+}
+
+type DecodeParamError struct {
+	err string
+}
+
+func (e *DecodeParamError) Error() string {
+	return fmt.Sprintf("could not decode, %s", e.err)
+
+}
+
+func NewDecodeParamError(errstr string) error {
+	return &DecodeParamError{
+		err: errstr,
+	}
+}
+
+type ValidationError struct {
+	ParamName string
+	msg       string
+}
+
+func (e *ValidationError) Error() string {
+	return fmt.Sprintf("%s not valid, %s", e.ParamName, e.msg)
+}
+
+func NewValidationError(param string, msg string) error {
+	return &ValidationError{
+		ParamName: param,
+		msg:       msg,
+	}
+}
 
 type RpcRequest struct {
 	ID      interface{}     `json:"id"`
@@ -53,35 +106,3 @@ type RpcErrorObject struct {
 	Message string `json:"message"`
 	// Data    interface{} `json:"data"`
 }
-
-func NewErrorWithMessage(err error, msg string) error {
-	return fmt.Errorf("%s: %s", err.Error(), msg)
-}
-
-// func (req *RpcRequest) ToRegisterArgs() (string, error) {
-// 	if len(req.Params) < 1 {
-// 		return "", errArguments
-// 	}
-
-// 	var args string
-// 	err := json.Unmarshal(req.Params, &args)
-// 	if err != nil {
-// 		return "", err
-// 	}
-
-// 	return args, nil
-// }
-
-// func (req *RpcRequest) ToWatchTxArgs() (string, error) {
-// 	if len(req.Params) < 1 {
-// 		return "", errArguments
-// 	}
-
-// 	var args string
-// 	err := json.Unmarshal(req.Params, &args)
-// 	if err != nil {
-// 		return "", err
-// 	}
-
-// 	return args, nil
-// }

rpc/util.go

@@ -42,7 +42,7 @@ type JsonWrapper struct{}
 func UnmarshalRawMessages(b []byte, iface interface{}, number *int64) (err error) {
 	var data []json.RawMessage
 	if err = json.Unmarshal(b, &data); err != nil && len(data) == 0 {
-		return errDecodeArgs
+		return NewDecodeParamError(err.Error())
 	}
 
 	// Number index determines the index in the array for a possible block number
@@ -74,7 +74,7 @@ func UnmarshalRawMessages(b []byte, iface interface{}, number *int64) (err error
 		fallthrough
 	default:
 		if err = json.Unmarshal(data[0], iface); err != nil {
-			return errDecodeArgs
+			return NewDecodeParamError(err.Error())
 		}
 		numberIndex = 1
 	}
@@ -82,7 +82,7 @@ func UnmarshalRawMessages(b []byte, iface interface{}, number *int64) (err error
 	// <0 index means out of bound for block number
 	if numberIndex >= 0 && len(data) > numberIndex {
 		if err = blockNumber(data[numberIndex], number); err != nil {
-			return errDecodeArgs
+			return NewDecodeParamError(err.Error())
 		}
 	}