feat(state-transition): add forkSeq to IBeaconStateView

packages/state-transition/src/stateView/beaconStateView.ts

@@ -108,6 +108,10 @@ export class BeaconStateView implements IBeaconStateViewLatestFork {
     return this.config.getForkName(this.cachedState.slot);
   }
 
+  get forkSeq(): ForkSeq {
+    return this.config.getForkSeq(this.cachedState.slot);
+  }
+
   get slot(): number {
     return this.cachedState.slot;
   }

packages/state-transition/src/stateView/interface.ts

@@ -10,6 +10,7 @@ import {
   ForkPostFulu,
   ForkPostGloas,
   ForkPostHeze,
+  ForkSeq,
   isForkPostAltair,
   isForkPostBellatrix,
   isForkPostCapella,
@@ -62,6 +63,7 @@ export interface IBeaconStateView {
 
   // phase0
   forkName: ForkName;
+  forkSeq: ForkSeq;
   slot: Slot;
   fork: Fork;
   epoch: Epoch;

packages/state-transition/src/stateView/nativeBeaconStateView.ts

@@ -1,6 +1,6 @@
 import {CompactMultiProof} from "@chainsafe/persistent-merkle-tree";
 import {BitArray, ByteViews} from "@chainsafe/ssz";
-import {ForkName} from "@lodestar/params";
+import {ForkName, ForkSeq} from "@lodestar/params";
 import {
   BeaconBlock,
   BeaconState,
@@ -63,6 +63,7 @@ import {
 export class NativeBeaconStateView implements IBeaconStateViewLatestFork {
   // phase0
   private _forkName: ForkName | null = null;
+  private _forkSeq: ForkSeq | null = null;
   private _slot: Slot | null = null;
   private _fork: Fork | null = null;
   private _epoch: Epoch | null = null;
@@ -191,6 +192,13 @@ export class NativeBeaconStateView implements IBeaconStateViewLatestFork {
     return this._forkName;
   }
 
+  get forkSeq(): ForkSeq {
+    if (this._forkSeq === null) {
+      this._forkSeq = this.binding.forkSeq;
+    }
+    return this._forkSeq;
+  }
+
   get slot(): Slot {
     if (this._slot === null) {
       this._slot = this.binding.slot;

packages/state-transition/test/unit/stateView/nativeBeaconStateView.test.ts

@@ -1,5 +1,6 @@
 import {describe, expect, it} from "vitest";
 import {BitArray} from "@chainsafe/ssz";
+import {ForkSeq} from "@lodestar/params";
 import {IBeaconStateViewNative} from "../../../src/stateView/interface.js";
 import {NativeBeaconStateView} from "../../../src/stateView/nativeBeaconStateView.js";
 
@@ -37,6 +38,7 @@ describe("NativeBeaconStateView", () => {
   it("caches forwarded properties so the binding is hit once", () => {
     let forkAccessCount = 0;
     let latestBlockHeaderAccessCount = 0;
+    let forkSeqAccessCount = 0;
     const fakeFork = {previousVersion: new Uint8Array(4), currentVersion: new Uint8Array(4), epoch: 0};
     const fakeHeader = {
       slot: 0,
@@ -55,15 +57,22 @@ describe("NativeBeaconStateView", () => {
         latestBlockHeaderAccessCount++;
         return fakeHeader;
       },
+      get forkSeq() {
+        forkSeqAccessCount++;
+        return ForkSeq.electra;
+      },
     } as unknown as IBeaconStateViewNative;
 
     const view = new NativeBeaconStateView(binding);
     expect(view.fork).toBe(fakeFork);
     expect(view.fork).toBe(fakeFork);
     expect(view.latestBlockHeader).toBe(fakeHeader);
     expect(view.latestBlockHeader).toBe(fakeHeader);
+    expect(view.forkSeq).toBe(ForkSeq.electra);
+    expect(view.forkSeq).toBe(ForkSeq.electra);
     expect(forkAccessCount).toBe(1);
     expect(latestBlockHeaderAccessCount).toBe(1);
+    expect(forkSeqAccessCount).toBe(1);
   });
 
   it("delegates pass-through getters and methods to the binding", () => {