Add address related utils

package.json

@@ -38,6 +38,7 @@
   },
   "dependencies": {
     "@ethereumjs/tx": "^4.1.2",
+    "@noble/hashes": "^1.3.1",
     "@types/debug": "^4.1.7",
     "debug": "^4.3.4",
     "semver": "^7.3.8",

src/hex.test.ts

@@ -1,9 +1,12 @@
 import {
+  Hex,
   add0x,
   assertIsHexString,
   assertIsStrictHexString,
+  isValidChecksumAddress,
   isHexString,
   isStrictHexString,
+  isValidHexAddress,
   remove0x,
 } from './hex';
 
@@ -151,6 +154,64 @@ describe('assertIsStrictHexString', () => {
   });
 });
 
+describe('isValidHexAddress', () => {
+  it.each([
+    '0x0000000000000000000000000000000000000000' as Hex,
+    '0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045' as Hex,
+  ])('returns true for a valid prefixed hex address', (hexString) => {
+    expect(isValidHexAddress(hexString)).toBe(true);
+  });
+
+  it.each([
+    '0000000000000000000000000000000000000000',
+    'd8dA6BF26964aF9D7eEd9e03E53415D37aA96045',
+  ])('returns false for a valid non-prefixed hex address', (hexString) => {
+    // @ts-expect-error - testing invalid input
+    expect(isValidHexAddress(hexString)).toBe(false);
+  });
+
+  it.each([
+    '12345g',
+    '1234567890abcdefg',
+    '1234567890abcdefG',
+    '1234567890abcdefABCDEFg',
+    '1234567890abcdefABCDEF1234567890abcdefABCDEFg',
+    '0x',
+    '0x0',
+    '0x12345g',
+    '0x1234567890abcdefg',
+    '0x1234567890abcdefG',
+    '0x1234567890abcdefABCDEFg',
+    '0x1234567890abcdefABCDEF1234567890abcdefABCDEFg',
+    '0xD8DA6BF26964AF9D7EED9E03E53415D37AA96045',
+    '0xCF5609B003B2776699EEA1233F7C82D5695CC9AA',
+    '0Xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045',
+  ])('returns false for an invalid hex address', (hexString) => {
+    // @ts-expect-error - testing invalid input
+    expect(isValidHexAddress(hexString)).toBe(false);
+  });
+});
+
+describe('isValidChecksumAddress', () => {
+  it.each([
+    '0x0000000000000000000000000000000000000000' as Hex,
+    '0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045' as Hex,
+    '0xCf5609B003B2776699eEA1233F7C82D5695cC9AA' as Hex,
+    '0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045' as Hex,
+    '0x8617E340B3D01FA5F11F306F4090FD50E238070D' as Hex,
+  ])('returns true for a valid checksum address', (hexString) => {
+    expect(isValidChecksumAddress(hexString)).toBe(true);
+  });
+
+  it.each([
+    '0xz' as Hex,
+    '0xD8DA6BF26964AF9D7EED9E03E53415D37AA96045' as Hex,
+    '0xCF5609B003B2776699EEA1233F7C82D5695CC9AA' as Hex,
+  ])('returns false for an invalid checksum address', (hexString) => {
+    expect(isValidChecksumAddress(hexString)).toBe(false);
+  });
+});
+
 describe('add0x', () => {
   it('adds a 0x-prefix to a string', () => {
     expect(add0x('12345')).toBe('0x12345');

src/hex.ts

@@ -1,6 +1,8 @@
+import { keccak_256 as keccak256 } from '@noble/hashes/sha3';
 import { is, pattern, string, Struct } from 'superstruct';
 
 import { assert } from './assert';
+import { bytesToHex } from './bytes';
 
 export type Hex = `0x${string}`;
 
@@ -9,6 +11,14 @@ export const StrictHexStruct = pattern(string(), /^0x[0-9a-f]+$/iu) as Struct<
   Hex,
   null
 >;
+export const HexAddressStruct = pattern(
+  string(),
+  /^0x[0-9a-f]{40}$/u,
+) as Struct<Hex, null>;
+export const HexChecksumAddressStruct = pattern(
+  string(),
+  /^0x[0-9a-fA-F]{40}$/u,
+) as Struct<Hex, null>;
 
 /**
  * Check if a string is a valid hex string.
@@ -55,6 +65,50 @@ export function assertIsStrictHexString(value: unknown): asserts value is Hex {
   );
 }
 
+/**
+ * Validate that the passed prefixed hex string is a valid hex address, or a
+ * valid mixed-case checksum address.
+ *
+ * @param possibleAddress - Input parameter to check against.
+ * @returns Whether or not the input is a valid hex address.
+ */
+export function isValidHexAddress(possibleAddress: Hex) {
+  return (
+    is(possibleAddress, HexAddressStruct) ||
+    isValidChecksumAddress(possibleAddress)
+  );
+}
+
+/**
+ * Validate that the passed hex string is a valid ERC-55 mixed-case
+ * checksum address.
+ *
+ * @param possibleChecksum - The hex address to check.
+ * @returns True if the address is a checksum address.
+ */
+export function isValidChecksumAddress(possibleChecksum: Hex) {
+  if (!is(possibleChecksum, HexChecksumAddressStruct)) {
+    return false;
+  }
+
+  const unPrefixed = remove0x(possibleChecksum);
+  const unPrefixedHash = remove0x(
+    bytesToHex(keccak256(unPrefixed.toLowerCase())),
+  );
+
+  for (let i = 0; i < unPrefixedHash.length; i++) {
+    const value = parseInt(unPrefixedHash[i] as string, 16);
+    if (
+      (value > 7 && unPrefixed[i]?.toUpperCase() !== unPrefixed[i]) ||
+      (value <= 7 && unPrefixed[i]?.toLowerCase() !== unPrefixed[i])
+    ) {
+      return false;
+    }
+  }
+
+  return true;
+}
+
 /**
  * Add the `0x`-prefix to a hexadecimal string. If the string already has the
  * prefix, it is returned as-is.

yarn.lock

@@ -1069,6 +1069,7 @@ __metadata:
     "@metamask/eslint-config-jest": ^11.0.0
     "@metamask/eslint-config-nodejs": ^11.0.1
     "@metamask/eslint-config-typescript": ^11.0.0
+    "@noble/hashes": ^1.3.1
     "@types/debug": ^4.1.7
     "@types/jest": ^28.1.7
     "@types/node": ^17.0.23
@@ -1108,13 +1109,20 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@noble/hashes@npm:1.3.0, @noble/hashes@npm:^1.3.0, @noble/hashes@npm:~1.3.0":
+"@noble/hashes@npm:1.3.0":
   version: 1.3.0
   resolution: "@noble/hashes@npm:1.3.0"
   checksum: d7ddb6d7c60f1ce1f87facbbef5b724cdea536fc9e7f59ae96e0fc9de96c8f1a2ae2bdedbce10f7dcc621338dfef8533daa73c873f2b5c87fa1a4e05a95c2e2e
   languageName: node
   linkType: hard
 
+"@noble/hashes@npm:^1.3.0, @noble/hashes@npm:^1.3.1, @noble/hashes@npm:~1.3.0":
+  version: 1.3.1
+  resolution: "@noble/hashes@npm:1.3.1"
+  checksum: 7fdefc0f7a0c1ec27acc6ff88841793e3f93ec4ce6b8a6a12bfc0dd70ae6b7c4c82fe305fdfeda1735d5ad4a9eebe761e6693b3d355689c559e91242f4bc95b1
+  languageName: node
+  linkType: hard
+
 "@nodelib/fs.scandir@npm:2.1.5":
   version: 2.1.5
   resolution: "@nodelib/fs.scandir@npm:2.1.5"