accounts, console, internal, rpc: minor error interface cleanups

accounts/abi/bind/backends/simulated.go

@@ -352,24 +352,27 @@ func newRevertError(result *core.ExecutionResult) *revertError {
 		err = fmt.Errorf("execution reverted: %v", reason)
 	}
 	return &revertError{
-		error:   err,
-		errData: hexutil.Encode(result.Revert()),
+		error:  err,
+		reason: hexutil.Encode(result.Revert()),
 	}
 }
 
+// revertError is an API error that encompassas an EVM revertal with JSON error
+// code and a binary data blob.
 type revertError struct {
 	error
-	errData interface{} // additional data
+	reason string // revert reason hex encoded
 }
 
-func (e revertError) ErrorCode() int {
-	// revert errors are execution errors.
-	// See: https://github.com/ethereum/wiki/wiki/JSON-RPC-Error-Codes-Improvement-Proposal
+// Core returns the JSON error code for a revertal.
+// See: https://github.com/ethereum/wiki/wiki/JSON-RPC-Error-Codes-Improvement-Proposal
+func (e *revertError) Code() int {
 	return 3
 }
 
-func (e revertError) ErrorData() interface{} {
-	return e.errData
+// Data returns the hex encoded revert reason.
+func (e *revertError) Data() interface{} {
+	return e.reason
 }
 
 // CallContract executes a contract call.

accounts/abi/bind/backends/simulated_test.go

@@ -463,10 +463,10 @@ func TestSimulatedBackend_EstimateGas(t *testing.T) {
 				t.Fatalf("Expect error, want %v, got %v", c.expectError, err)
 			}
 			if c.expectData != nil {
-				if rerr, ok := err.(*revertError); !ok {
+				if err, ok := err.(*revertError); !ok {
 					t.Fatalf("Expect revert error, got %T", err)
-				} else if !reflect.DeepEqual(rerr.ErrorData(), c.expectData) {
-					t.Fatalf("Error data mismatch, want %v, got %v", c.expectData, rerr.ErrorData())
+				} else if !reflect.DeepEqual(err.Data(), c.expectData) {
+					t.Fatalf("Error data mismatch, want %v, got %v", c.expectData, err.Data())
 				}
 			}
 			continue

console/bridge.go

@@ -413,9 +413,7 @@ func (b *bridge) Send(call jsre.Call) (goja.Value, error) {
 		resp.Set("id", req.ID)
 
 		var result json.RawMessage
-		err = b.client.Call(&result, req.Method, req.Params...)
-		switch err := err.(type) {
-		case nil:
+		if err = b.client.Call(&result, req.Method, req.Params...); err == nil {
 			if result == nil {
 				// Special case null because it is decoded as an empty
 				// raw message for some reason.
@@ -433,18 +431,21 @@ func (b *bridge) Send(call jsre.Call) (goja.Value, error) {
 					resp.Set("result", resultVal)
 				}
 			}
-		case rpc.Error:
-			if dataErr, ok := err.(rpc.DataError); ok {
-				setError(resp, err.ErrorCode(), err.Error(), dataErr.ErrorData())
-			} else {
-				setError(resp, err.ErrorCode(), err.Error(), nil)
+		} else {
+			var (
+				code int         = -32603
+				data interface{} = nil
+			)
+			if err, ok := err.(rpc.ErrorWithCode); ok {
+				code = err.Code()
+			}
+			if err, ok := err.(rpc.ErrorWithData); ok {
+				data = err.Data()
 			}
-		default:
-			setError(resp, -32603, err.Error(), nil)
+			setError(resp, code, err.Error(), data)
 		}
 		resps = append(resps, resp)
 	}
-
 	// Return the responses either to the callback (if supplied)
 	// or directly as the return value.
 	var result goja.Value

internal/ethapi/api.go

@@ -871,24 +871,27 @@ func newRevertError(result *core.ExecutionResult) *revertError {
 		err = fmt.Errorf("execution reverted: %v", reason)
 	}
 	return &revertError{
-		error:   err,
-		errData: hexutil.Encode(result.Revert()),
+		error:  err,
+		reason: hexutil.Encode(result.Revert()),
 	}
 }
 
+// revertError is an API error that encompassas an EVM revertal with JSON error
+// code and a binary data blob.
 type revertError struct {
 	error
-	errData interface{} // additional data
+	reason string // revert reason hex encoded
 }
 
-func (e revertError) ErrorCode() int {
-	// revert errors are execution errors.
-	// See: https://github.com/ethereum/wiki/wiki/JSON-RPC-Error-Codes-Improvement-Proposal
+// Core returns the JSON error code for a revertal.
+// See: https://github.com/ethereum/wiki/wiki/JSON-RPC-Error-Codes-Improvement-Proposal
+func (e *revertError) Code() int {
 	return 3
 }
 
-func (e revertError) ErrorData() interface{} {
-	return e.errData
+// Data returns the hex encoded revert reason.
+func (e *revertError) Data() interface{} {
+	return e.reason
 }
 
 // Call executes the given transaction on the state for the given block number.

rpc/errors.go

@@ -18,20 +18,27 @@ package rpc
 
 import "fmt"
 
+var (
+	_ ErrorWithCode = new(methodNotFoundError)
+	_ ErrorWithCode = new(subscriptionNotFoundError)
+	_ ErrorWithCode = new(parseError)
+	_ ErrorWithCode = new(invalidRequestError)
+	_ ErrorWithCode = new(invalidMessageError)
+	_ ErrorWithCode = new(invalidParamsError)
+)
+
 const defaultErrorCode = -32000
 
 type methodNotFoundError struct{ method string }
 
-func (e *methodNotFoundError) ErrorCode() int { return -32601 }
-
+func (e *methodNotFoundError) Code() int { return -32601 }
 func (e *methodNotFoundError) Error() string {
 	return fmt.Sprintf("the method %s does not exist/is not available", e.method)
 }
 
 type subscriptionNotFoundError struct{ namespace, subscription string }
 
-func (e *subscriptionNotFoundError) ErrorCode() int { return -32601 }
-
+func (e *subscriptionNotFoundError) Code() int { return -32601 }
 func (e *subscriptionNotFoundError) Error() string {
 	return fmt.Sprintf("no %q subscription in %s namespace", e.subscription, e.namespace)
 }
@@ -39,27 +46,23 @@ func (e *subscriptionNotFoundError) Error() string {
 // Invalid JSON was received by the server.
 type parseError struct{ message string }
 
-func (e *parseError) ErrorCode() int { return -32700 }
-
+func (e *parseError) Code() int     { return -32700 }
 func (e *parseError) Error() string { return e.message }
 
 // received message isn't a valid request
 type invalidRequestError struct{ message string }
 
-func (e *invalidRequestError) ErrorCode() int { return -32600 }
-
+func (e *invalidRequestError) Code() int     { return -32600 }
 func (e *invalidRequestError) Error() string { return e.message }
 
 // received message is invalid
 type invalidMessageError struct{ message string }
 
-func (e *invalidMessageError) ErrorCode() int { return -32700 }
-
+func (e *invalidMessageError) Code() int     { return -32700 }
 func (e *invalidMessageError) Error() string { return e.message }
 
 // unable to decode supplied params, or an invalid number of parameters
 type invalidParamsError struct{ message string }
 
-func (e *invalidParamsError) ErrorCode() int { return -32602 }
-
+func (e *invalidParamsError) Code() int     { return -32602 }
 func (e *invalidParamsError) Error() string { return e.message }

rpc/handler.go

@@ -301,7 +301,7 @@ func (h *handler) handleCallMsg(ctx *callProc, msg *jsonrpcMessage) *jsonrpcMess
 		if resp.Error != nil {
 			ctx = append(ctx, "err", resp.Error.Message)
 			if resp.Error.Data != nil {
-				ctx = append(ctx, "errdata", resp.Error.Data)
+				ctx = append(ctx, "data", resp.Error.Data)
 			}
 			h.log.Warn("Served "+msg.Method, ctx...)
 		} else {

rpc/json.go

@@ -111,13 +111,13 @@ func errorMessage(err error) *jsonrpcMessage {
 		Code:    defaultErrorCode,
 		Message: err.Error(),
 	}}
-	ec, ok := err.(Error)
+	ec, ok := err.(ErrorWithCode)
 	if ok {
-		msg.Error.Code = ec.ErrorCode()
+		msg.Error.Code = ec.Code()
 	}
-	de, ok := err.(DataError)
+	de, ok := err.(ErrorWithData)
 	if ok {
-		msg.Error.Data = de.ErrorData()
+		msg.Error.Data = de.Data()
 	}
 	return msg
 }
@@ -135,14 +135,6 @@ func (err *jsonError) Error() string {
 	return err.Message
 }
 
-func (err *jsonError) ErrorCode() int {
-	return err.Code
-}
-
-func (err *jsonError) ErrorData() interface{} {
-	return err.Data
-}
-
 // Conn is a subset of the methods of net.Conn which are sufficient for ServerCodec.
 type Conn interface {
 	io.ReadWriteCloser

rpc/types.go

@@ -35,16 +35,14 @@ type API struct {
 	Public    bool        // indication if the methods must be considered safe for public use
 }
 
-// Error wraps RPC errors, which contain an error code in addition to the message.
-type Error interface {
-	Error() string  // returns the message
-	ErrorCode() int // returns the code
+// ErrorWithCode defines an error code in addition to the message.
+type ErrorWithCode interface {
+	Code() int // returns the code
 }
 
-// A DataError contains some data in addition to the error message.
-type DataError interface {
-	Error() string          // returns the message
-	ErrorData() interface{} // returns the error data
+// ErrorWithData defines a data item in addition to the message.
+type ErrorWithData interface {
+	Data() interface{} // returns the error data
 }
 
 // ServerCodec implements reading, parsing and writing RPC messages for the server side of