Util, Block: added Util error module, first exemplary BlockHeader err…

…or implementation

packages/block/src/errors.ts

@@ -0,0 +1,12 @@
+import { EthereumJSError } from '@ethereumjs/util'
+
+export enum HeaderValidationErrorCode {
+  WRONG_TX_TRIE_LENGTH = 'WRONG_TX_TRIE_LENGTH',
+}
+
+export type HeaderValidationErrorType = {
+  block: string
+  received: string
+}
+
+export class HeaderValidationError extends EthereumJSError<HeaderValidationErrorType> {}

packages/block/src/header/header.ts

@@ -26,6 +26,7 @@ import {
   CLIQUE_EXTRA_VANITY,
   cliqueIsEpochTransition,
 } from '../consensus/clique.js'
+import { HeaderValidationError, HeaderValidationErrorCode } from '../errors.js'
 import { fakeExponential } from '../helpers.js'
 import { paramsBlock } from '../params.js'
 
@@ -267,10 +268,15 @@ export class BlockHeader {
       throw new Error(msg)
     }
     if (transactionsTrie.length !== 32) {
-      const msg = this._errorMsg(
-        `transactionsTrie must be 32 bytes, received ${transactionsTrie.length} bytes`,
+      const e = new HeaderValidationError(
+        'transactionsTrie must be 32 bytes',
+        HeaderValidationErrorCode.WRONG_TX_TRIE_LENGTH,
+        {
+          block: this.errorStr(),
+          received: `${bytesToHex(transactionsTrie)} (${transactionsTrie.length} bytes)`,
+        },
       )
-      throw new Error(msg)
+      throw e
     }
     if (receiptTrie.length !== 32) {
       const msg = this._errorMsg(

packages/util/src/errors.ts

@@ -0,0 +1,30 @@
+/**
+ * Generic EthereumJS error with metadata attached
+ *
+ * Kudos to https://github.com/ChainSafe/lodestar monorepo
+ * for the inspiration :-)
+ */
+export class EthereumJSError<T extends {}> extends Error {
+  code: string
+  errorContext: T
+
+  constructor(msg: string, code: string, errorContext: T) {
+    super(msg)
+    this.code = code
+    this.errorContext = errorContext
+  }
+
+  getErrorContext(): Record<string, string | number | null> {
+    return { code: this.code, ...this.errorContext }
+  }
+
+  /**
+   * Get the metadata and the stacktrace for the error.
+   */
+  toObject(): Record<string, string | number | null> {
+    return {
+      ...this.getErrorContext(),
+      stack: this.stack ?? '',
+    }
+  }
+}

packages/util/src/index.ts

@@ -28,6 +28,11 @@ export * from './db.js'
  */
 export * from './withdrawal.js'
 
+/**
+ * EthereumJS Extended Errors
+ */
+export * from './errors.js'
+
 /**
  * ECDSA signature
  */