feat: validate blob schedule on startup

packages/config/src/chainConfig/json.ts

@@ -1,4 +1,5 @@
 import {fromHex, toHex} from "@lodestar/utils";
+import {validateBlobSchedule} from "../utils/validateBlobSchedule.js";
 import {
   BlobSchedule,
   BlobScheduleEntry,
@@ -168,5 +169,7 @@ export function deserializeBlobSchedule(input: unknown): BlobSchedule {
     return out;
   });
 
+  validateBlobSchedule(blobSchedule);
+
   return blobSchedule;
 }

packages/config/src/forkConfig/index.ts

@@ -149,12 +149,7 @@ export function createForkConfig(config: ChainConfig): ForkConfig {
       }
 
       // Sort by epoch in descending order to find the latest applicable value
-      const blobSchedule = [...config.BLOB_SCHEDULE].sort((a, b) => {
-        if (a.EPOCH !== b.EPOCH) {
-          return b.EPOCH - a.EPOCH;
-        }
-        return b.MAX_BLOBS_PER_BLOCK - a.MAX_BLOBS_PER_BLOCK;
-      });
+      const blobSchedule = [...config.BLOB_SCHEDULE].sort((a, b) => b.EPOCH - a.EPOCH);
 
       for (const entry of blobSchedule) {
         if (epoch >= entry.EPOCH) {

packages/config/src/utils/validateBlobSchedule.ts

@@ -0,0 +1,32 @@
+import {MAX_BLOB_COMMITMENTS_PER_BLOCK} from "@lodestar/params";
+import {BlobSchedule} from "../chainConfig/types.js";
+
+export function validateBlobSchedule(blobSchedule: BlobSchedule): void {
+  if (blobSchedule.length === 0) {
+    return;
+  }
+
+  let previousEpoch: number | undefined;
+
+  for (const [i, entry] of blobSchedule.entries()) {
+    if (previousEpoch !== undefined) {
+      if (entry.EPOCH < previousEpoch) {
+        throw Error(
+          `Invalid BLOB_SCHEDULE expected entries to be sorted by EPOCH in ascending order, ${entry.EPOCH} < ${previousEpoch} at index ${i}`
+        );
+      }
+      if (entry.EPOCH === previousEpoch) {
+        throw Error(
+          `Invalid BLOB_SCHEDULE[${i}] entry with the same epoch value ${entry.EPOCH} as previous BLOB_SCHEDULE[${i - 1}] entry`
+        );
+      }
+    }
+    if (entry.MAX_BLOBS_PER_BLOCK > MAX_BLOB_COMMITMENTS_PER_BLOCK) {
+      throw Error(
+        `Invalid BLOB_SCHEDULE[${i}].MAX_BLOBS_PER_BLOCK value ${entry.MAX_BLOBS_PER_BLOCK} exceeds limit ${MAX_BLOB_COMMITMENTS_PER_BLOCK}`
+      );
+    }
+
+    previousEpoch = entry.EPOCH;
+  }
+}

packages/config/test/unit/json.test.ts

@@ -1,3 +1,4 @@
+import {MAX_BLOB_COMMITMENTS_PER_BLOCK} from "@lodestar/params";
 import {describe, expect, it} from "vitest";
 import {chainConfig} from "../../src/default.js";
 import {BlobSchedule, chainConfigFromJson, chainConfigToJson} from "../../src/index.js";
@@ -13,9 +14,8 @@ describe("chainConfig JSON", () => {
   it("Custom blob schedule", () => {
     const blobSchedule: BlobSchedule = [
       {EPOCH: 0, MAX_BLOBS_PER_BLOCK: 10},
-      {EPOCH: 10, MAX_BLOBS_PER_BLOCK: Infinity},
+      {EPOCH: 10, MAX_BLOBS_PER_BLOCK: 15},
       {EPOCH: Infinity, MAX_BLOBS_PER_BLOCK: 20},
-      {EPOCH: Infinity, MAX_BLOBS_PER_BLOCK: Infinity},
     ];
     const configWithCustomBlobSchedule = {...chainConfig, BLOB_SCHEDULE: blobSchedule};
 
@@ -24,4 +24,41 @@ describe("chainConfig JSON", () => {
 
     expect(chainConfigRes).toEqual(configWithCustomBlobSchedule);
   });
+
+  it("Blob schedule max blobs exceeds limit", () => {
+    const blobSchedule: BlobSchedule = [{EPOCH: 0, MAX_BLOBS_PER_BLOCK: MAX_BLOB_COMMITMENTS_PER_BLOCK + 1}];
+    const configWithCustomBlobSchedule = {...chainConfig, BLOB_SCHEDULE: blobSchedule};
+
+    const json = chainConfigToJson(configWithCustomBlobSchedule);
+
+    expect(() => chainConfigFromJson(json)).toThrow();
+  });
+
+  it("Blob schedule in wrong order", () => {
+    const blobSchedule: BlobSchedule = [
+      {EPOCH: 20, MAX_BLOBS_PER_BLOCK: 20},
+      {EPOCH: 10, MAX_BLOBS_PER_BLOCK: 15},
+      {EPOCH: 0, MAX_BLOBS_PER_BLOCK: 10},
+    ];
+
+    const configWithCustomBlobSchedule = {...chainConfig, BLOB_SCHEDULE: blobSchedule};
+
+    const json = chainConfigToJson(configWithCustomBlobSchedule);
+
+    expect(() => chainConfigFromJson(json)).toThrow();
+  });
+
+  it("Blob schedule entries with the same epoch value", () => {
+    const blobSchedule: BlobSchedule = [
+      {EPOCH: 0, MAX_BLOBS_PER_BLOCK: 10},
+      {EPOCH: 10, MAX_BLOBS_PER_BLOCK: 15},
+      {EPOCH: 10, MAX_BLOBS_PER_BLOCK: 20},
+    ];
+
+    const configWithCustomBlobSchedule = {...chainConfig, BLOB_SCHEDULE: blobSchedule};
+
+    const json = chainConfigToJson(configWithCustomBlobSchedule);
+
+    expect(() => chainConfigFromJson(json)).toThrow();
+  });
 });