chore: getChecksumAddress memoized and faster

jest.config.js

@@ -26,6 +26,7 @@ module.exports = {
     './src/**/*.ts',
     '!./src/__fixtures__/**/*',
     '!./src/**/*.test-d.ts',
+    '!./src/index.ts',
   ],
 
   // The directory where Jest should output its coverage files

package.json

@@ -67,6 +67,7 @@
     "@scure/base": "^1.1.3",
     "@types/debug": "^4.1.7",
     "debug": "^4.3.4",
+    "lodash.memoize": "^4.1.2",
     "pony-cause": "^2.1.10",
     "semver": "^7.5.4",
     "uuid": "^9.0.1"
@@ -83,6 +84,7 @@
     "@ts-bridge/shims": "^0.1.1",
     "@types/jest": "^28.1.7",
     "@types/jest-when": "^3.5.3",
+    "@types/lodash.memoize": "^4.1.9",
     "@types/node": "~18.18.14",
     "@types/uuid": "^9.0.8",
     "@typescript-eslint/eslint-plugin": "^5.43.0",

src/hex.test.ts

@@ -8,7 +8,8 @@ import {
   isStrictHexString,
   isValidHexAddress,
   remove0x,
-  getChecksumAddress,
+  getChecksumAddressUnmemoized as getChecksumAddress,
+  getChecksumAddress as getChecksumAddressMemoized,
 } from './hex';
 
 describe('isHexString', () => {
@@ -211,6 +212,22 @@ describe('getChecksumAddress', () => {
       getChecksumAddress('0xde709f2102306220921060314715629080e2fb77'),
     ).toBe('0xde709f2102306220921060314715629080e2fb77');
 
+    expect(
+      getChecksumAddress('0x8617e340b3d01fa5f11f306f4090fd50e238070d'),
+    ).toBe('0x8617E340B3D01FA5F11F306F4090FD50E238070D');
+
+    expect(
+      getChecksumAddress('0x27b1fdb04752bbc536007a920d24acb045561c26'),
+    ).toBe('0x27b1fdb04752bbc536007a920d24acb045561c26');
+
+    expect(
+      getChecksumAddress('0xdbf03b407c01e7cd3cbea99509d93f8dddc8c6fb'),
+    ).toBe('0xdbF03B407c01E7cD3CBea99509d93f8DDDC8C6FB');
+
+    expect(
+      getChecksumAddress('0xd1220a0cf47c7b9be7a2e6ba89f429762e7b9adb'),
+    ).toBe('0xD1220A0cf47c7B9Be7A2E6BA89F429762e7b9aDb');
+
     expect(
       getChecksumAddress('0x0000000000000000000000000000000000000000'),
     ).toBe('0x0000000000000000000000000000000000000000');
@@ -221,13 +238,50 @@ describe('getChecksumAddress', () => {
   });
 });
 
+describe('getChecksumAddress (memoized)', () => {
+  it('memoizes results for repeated calls with the same input', () => {
+    const address = '0x5aaeb6053f3e94c9b9a09f33669435e7ef1beaed' as Hex;
+    const expected = '0x5aAeb6053F3E94C9b9A09f33669435E7Ef1BeAed';
+
+    // First call should compute the result
+    const result1 = getChecksumAddressMemoized(address);
+    expect(result1).toBe(expected);
+
+    // Second call with the same input should return the cached result
+    const result2 = getChecksumAddressMemoized(address);
+    expect(result2).toBe(expected);
+
+    // Results should be the same object reference (memoized)
+    expect(result1).toBe(result2);
+  });
+
+  it('handles different inputs correctly', () => {
+    const address1 = '0x5aaeb6053f3e94c9b9a09f33669435e7ef1beaed' as Hex;
+    const address2 = '0xfb6916095ca1df60bb79ce92ce3ea74c37c5d359' as Hex;
+
+    const result1 = getChecksumAddressMemoized(address1);
+    const result2 = getChecksumAddressMemoized(address2);
+
+    expect(result1).toBe('0x5aAeb6053F3E94C9b9A09f33669435E7Ef1BeAed');
+    expect(result2).toBe('0xfB6916095ca1df60bB79Ce92cE3Ea74c37c5d359');
+    expect(result1).not.toBe(result2);
+  });
+});
+
 describe('isValidChecksumAddress', () => {
   it.each([
     '0x0000000000000000000000000000000000000000' as Hex,
     '0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045' as Hex,
     '0xCf5609B003B2776699eEA1233F7C82D5695cC9AA' as Hex,
     '0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045' as Hex,
     '0x8617E340B3D01FA5F11F306F4090FD50E238070D' as Hex,
+    '0x52908400098527886E0F7030069857D2E4169EE7' as Hex,
+    '0xde709f2102306220921060314715629080e2fb77' as Hex,
+    '0x27b1fdb04752bbc536007a920d24acb045561c26' as Hex,
+    '0x5aAeb6053F3E94C9b9A09f33669435E7Ef1BeAed' as Hex,
+    '0xfB6916095ca1df60bB79Ce92cE3Ea74c37c5d359' as Hex,
+    '0xdbF03B407c01E7cD3CBea99509d93f8DDDC8C6FB' as Hex,
+    '0xD1220A0cf47c7B9Be7A2E6BA89F429762e7b9aDb' as Hex,
   ])('returns true for a valid checksum address', (hexString) => {
     expect(isValidChecksumAddress(hexString)).toBe(true);
   });

src/hex.ts

@@ -1,9 +1,9 @@
 import type { Struct } from '@metamask/superstruct';
 import { is, pattern, string } from '@metamask/superstruct';
 import { keccak_256 as keccak256 } from '@noble/hashes/sha3';
+import memoize from 'lodash.memoize';
 
 import { assert } from './assert';
-import { bytesToHex } from './bytes';
 
 export type Hex = `0x${string}`;
 
@@ -82,27 +82,44 @@ export function isValidHexAddress(possibleAddress: Hex) {
 
 /**
  * Encode a passed hex string as an ERC-55 mixed-case checksum address.
+ * This is the unmemoized version, primarily used for testing.
  *
- * @param address - The hex address to encode.
+ * @param hexAddress - The hex address to encode.
  * @returns The address encoded according to ERC-55.
  * @see https://eips.ethereum.org/EIPS/eip-55
  */
-export function getChecksumAddress(address: Hex): Hex {
-  assert(is(address, HexChecksumAddressStruct), 'Invalid hex address.');
-  const unPrefixed = remove0x(address.toLowerCase());
-  const unPrefixedHash = remove0x(bytesToHex(keccak256(unPrefixed)));
-  return `0x${unPrefixed
-    .split('')
-    .map((character, nibbleIndex) => {
-      const hashCharacter = unPrefixedHash[nibbleIndex];
-      assert(is(hashCharacter, string()), 'Hash shorter than address.');
-      return parseInt(hashCharacter, 16) > 7
-        ? character.toUpperCase()
-        : character;
-    })
-    .join('')}`;
+export function getChecksumAddressUnmemoized(hexAddress: Hex): Hex {
+  assert(is(hexAddress, HexChecksumAddressStruct), 'Invalid hex address.');
+  const address = remove0x(hexAddress).toLowerCase();
+
+  const hashBytes = keccak256(address);
+  const { length } = address;
+  const result = new Array(length); // Pre-allocate array
+
+  for (let i = 0; i < length; i++) {
+    /* eslint-disable no-bitwise */
+    const byteIndex = i >> 1; // Faster than Math.floor(i / 2)
+    const nibbleIndex = i & 1; // Faster than i % 2
+    const byte = hashBytes[byteIndex] as number;
+    const nibble = nibbleIndex === 0 ? byte >> 4 : byte & 0x0f;
+    /* eslint-enable no-bitwise */
+
+    result[i] = nibble >= 8 ? (address[i] as string).toUpperCase() : address[i];
+  }
+
+  return `0x${result.join('')}`;
 }
 
+/**
+ * Encode a passed hex string as an ERC-55 mixed-case checksum address.
+ * This function is memoized for performance.
+ *
+ * @param hexAddress - The hex address to encode.
+ * @returns The address encoded according to ERC-55.
+ * @see https://eips.ethereum.org/EIPS/eip-55
+ */
+export const getChecksumAddress = memoize(getChecksumAddressUnmemoized);
+
 /**
  * Validate that the passed hex string is a valid ERC-55 mixed-case
  * checksum address.

src/index.ts

@@ -7,7 +7,22 @@ export * from './coercers';
 export * from './collections';
 export * from './encryption-types';
 export * from './errors';
-export * from './hex';
+export type { Hex } from './hex';
+export {
+  HexStruct,
+  StrictHexStruct,
+  HexAddressStruct,
+  HexChecksumAddressStruct,
+  isHexString,
+  isStrictHexString,
+  assertIsHexString,
+  assertIsStrictHexString,
+  isValidHexAddress,
+  getChecksumAddress,
+  isValidChecksumAddress,
+  add0x,
+  remove0x,
+} from './hex';
 export * from './json';
 export * from './keyring';
 export * from './logging';

yarn.lock

@@ -1081,6 +1081,7 @@ __metadata:
     "@types/debug": ^4.1.7
     "@types/jest": ^28.1.7
     "@types/jest-when": ^3.5.3
+    "@types/lodash.memoize": ^4.1.9
     "@types/node": ~18.18.14
     "@types/uuid": ^9.0.8
     "@typescript-eslint/eslint-plugin": ^5.43.0
@@ -1098,6 +1099,7 @@ __metadata:
     jest: ^29.2.2
     jest-it-up: ^2.0.2
     jest-when: ^3.6.0
+    lodash.memoize: ^4.1.2
     pony-cause: ^2.1.10
     prettier: ^2.7.1
     prettier-plugin-packagejson: ^2.3.0
@@ -1551,6 +1553,22 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@types/lodash.memoize@npm:^4.1.9":
+  version: 4.1.9
+  resolution: "@types/lodash.memoize@npm:4.1.9"
+  dependencies:
+    "@types/lodash": "*"
+  checksum: d11efe604911aabbf9c49eb02e944de856619d6e0ab348d83be3ff07de245ee605ea71b1f3ee24b5c134286d02625119edf3ac2c0e6aa4732f699b1f4aa55240
+  languageName: node
+  linkType: hard
+
+"@types/lodash@npm:*":
+  version: 4.17.19
+  resolution: "@types/lodash@npm:4.17.19"
+  checksum: a75452bd0ed21c9dba98c0d395ef0f9de3220a8410dc07dfb041f84c7f1733b88648f1ba8e62b14f70ff9e935797b618f7060fba40abdf754cdbfb27a99ec27e
+  languageName: node
+  linkType: hard
+
 "@types/minimatch@npm:^3.0.3":
   version: 3.0.5
   resolution: "@types/minimatch@npm:3.0.5"
@@ -5279,7 +5297,7 @@ __metadata:
   languageName: node
   linkType: hard
 
-"lodash.memoize@npm:4.x":
+"lodash.memoize@npm:4.x, lodash.memoize@npm:^4.1.2":
   version: 4.1.2
   resolution: "lodash.memoize@npm:4.1.2"
   checksum: 9ff3942feeccffa4f1fafa88d32f0d24fdc62fd15ded5a74a5f950ff5f0c6f61916157246744c620173dddf38d37095a92327d5fd3861e2063e736a5c207d089