simulators/ethereum/engine: Refactor Test Verification Syntax

simulators/ethereum/engine/clmock.go

@@ -127,7 +127,7 @@ func (cl *CLMocker) setTTDBlockClient(ec *EngineClient) {
 		if resp.Error != nil {
 			cl.Logf("CLMocker: forkchoiceUpdated Error: %v\n", resp.Error)
 		} else {
-			if resp.ForkchoiceResponse.PayloadStatus.Status == "VALID" {
+			if resp.ForkchoiceResponse.PayloadStatus.Status == Valid {
 				anySuccess = true
 			} else {
 				cl.Logf("CLMocker: forkchoiceUpdated Response: %v\n", resp.ForkchoiceResponse)
@@ -220,7 +220,7 @@ func (cl *CLMocker) getNextPayloadID() {
 	if err != nil {
 		cl.Fatalf("CLMocker: Could not send forkchoiceUpdatedV1 (%v): %v", cl.NextBlockProducer.Client.Container, err)
 	}
-	if resp.PayloadStatus.Status != "VALID" {
+	if resp.PayloadStatus.Status != Valid {
 		cl.Fatalf("CLMocker: Unexpected forkchoiceUpdated Response from Payload builder: %v", resp)
 	}
 	cl.NextPayloadID = resp.PayloadID
@@ -241,7 +241,7 @@ func (cl *CLMocker) broadcastNextNewPayload() {
 			cl.Logf("CLMocker: broadcastNewPayload Error (%v): %v\n", resp.Container, resp.Error)
 
 		} else {
-			if resp.ExecutePayloadResponse.Status == "VALID" {
+			if resp.ExecutePayloadResponse.Status == Valid {
 				// The client is synced and the payload was immediately validated
 				// https://github.com/ethereum/execution-apis/blob/main/src/engine/specification.md:
 				// - If validation succeeds, the response MUST contain {status: VALID, latestValidHash: payload.blockHash}
@@ -251,7 +251,7 @@ func (cl *CLMocker) broadcastNextNewPayload() {
 				if *resp.ExecutePayloadResponse.LatestValidHash != cl.LatestPayloadBuilt.BlockHash {
 					cl.Fatalf("CLMocker: NewPayload returned VALID status with incorrect LatestValidHash==%v, expected %v", resp.ExecutePayloadResponse.LatestValidHash, cl.LatestPayloadBuilt.BlockHash)
 				}
-			} else if resp.ExecutePayloadResponse.Status == "ACCEPTED" {
+			} else if resp.ExecutePayloadResponse.Status == Accepted {
 				// The client is not synced but the payload was accepted
 				// https://github.com/ethereum/execution-apis/blob/main/src/engine/specification.md:
 				// - {status: ACCEPTED, latestValidHash: null, validationError: null} if the following conditions are met:
@@ -275,7 +275,7 @@ func (cl *CLMocker) broadcastLatestForkchoice() {
 	for _, resp := range cl.broadcastForkchoiceUpdated(&cl.LatestForkchoice, nil) {
 		if resp.Error != nil {
 			cl.Logf("CLMocker: broadcastForkchoiceUpdated Error (%v): %v\n", resp.Container, resp.Error)
-		} else if resp.ForkchoiceResponse.PayloadStatus.Status != "VALID" {
+		} else if resp.ForkchoiceResponse.PayloadStatus.Status != Valid {
 			cl.Logf("CLMocker: broadcastForkchoiceUpdated Response (%v): %v\n", resp.Container, resp.ForkchoiceResponse)
 		}
 	}

simulators/ethereum/engine/engineclient.go

@@ -6,6 +6,7 @@ import (
 	"math/big"
 	"net"
 	"net/http"
+	"strings"
 	"time"
 
 	"github.com/ethereum/go-ethereum/common"
@@ -155,15 +156,71 @@ func (ec *EngineClient) Ctx() context.Context {
 
 // Engine API Types
 type PayloadStatusV1 struct {
-	Status          string       `json:"status"`
-	LatestValidHash *common.Hash `json:"latestValidHash"`
-	ValidationError *string      `json:"validationError"`
+	Status          PayloadStatus `json:"status"`
+	LatestValidHash *common.Hash  `json:"latestValidHash"`
+	ValidationError *string       `json:"validationError"`
 }
 type ForkChoiceResponse struct {
 	PayloadStatus PayloadStatusV1 `json:"payloadStatus"`
 	PayloadID     *PayloadID      `json:"payloadId"`
 }
 
+type PayloadStatus int
+type PayloadStatusSlice []PayloadStatus
+
+const (
+	Valid PayloadStatus = iota
+	Invalid
+	Accepted
+	Syncing
+	InvalidTerminalBlock
+	InvalidBlockHash
+)
+
+var PayloadStatuses = map[PayloadStatus]string{
+	Valid:                "VALID",
+	Invalid:              "INVALID",
+	Accepted:             "ACCEPTED",
+	Syncing:              "SYNCING",
+	InvalidTerminalBlock: "INVALID_TERMINAL_BLOCK",
+	InvalidBlockHash:     "INVALID_BLOCK_HASH",
+}
+
+func (b PayloadStatus) String() string {
+	str, ok := PayloadStatuses[b]
+	if !ok {
+		return "UNKNOWN"
+	}
+	return str
+}
+
+func (b PayloadStatusSlice) String() string {
+	names := make([]string, 0)
+	for _, status := range b {
+		names = append(names, status.String())
+	}
+	return strings.Join(names, "|")
+}
+
+func (b PayloadStatus) MarshalText() ([]byte, error) {
+	str, ok := PayloadStatuses[b]
+	if !ok {
+		return nil, fmt.Errorf("invalid payload status")
+	}
+	return []byte(str), nil
+}
+
+func (b *PayloadStatus) UnmarshalText(input []byte) error {
+	s := string(input)
+	for p, status := range PayloadStatuses {
+		if status == s {
+			*b = p
+			return nil
+		}
+	}
+	return fmt.Errorf("invalid payload status: %s", s)
+}
+
 type PayloadID [8]byte
 
 func (b PayloadID) MarshalText() ([]byte, error) {