Add address related utils

src/hex.test.ts

@@ -1,9 +1,11 @@
 import {
+  Hex,
   add0x,
   assertIsHexString,
   assertIsStrictHexString,
   isHexString,
   isStrictHexString,
+  isValidHexAddress,
   remove0x,
 } from './hex';
 
@@ -151,6 +153,42 @@ 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',
+  ])('returns false for an invalid hex address', (hexString) => {
+    // @ts-expect-error - testing invalid input
+    expect(isValidHexAddress(hexString)).toBe(false);
+  });
+});
+
 describe('add0x', () => {
   it('adds a 0x-prefix to a string', () => {
     expect(add0x('12345')).toBe('0x12345');

src/hex.ts

@@ -9,6 +9,10 @@ export const StrictHexStruct = pattern(string(), /^0x[0-9a-f]+$/iu) as Struct<
   Hex,
   null
 >;
+export const HexAddressStruct = pattern(
+  string(),
+  /^0x[0-9a-fA-F]{40}$/u,
+) as Struct<Hex, null>;
 
 /**
  * Check if a string is a valid hex string.
@@ -55,6 +59,16 @@ export function assertIsStrictHexString(value: unknown): asserts value is Hex {
   );
 }
 
+/**
+ * Validates that the passed prefixed hex string is a valid hex 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);
+}
+
 /**
  * Add the `0x`-prefix to a hexadecimal string. If the string already has the
  * prefix, it is returned as-is.