feat: add isValidHexAddress function

Author: mikesposito

src/hex.test.ts

@@ -4,6 +4,7 @@ import {
   assertIsStrictHexString,
   isHexString,
   isStrictHexString,
+  isValidHexAddress,
   remove0x,
 } from './hex';
 
@@ -151,6 +152,54 @@ describe('assertIsStrictHexString', () => {
   });
 });
 
+describe('isValidHexAddress', () => {
+  describe('with allowNonPrefixed option set to true', () => {
+    it.each([
+      '0000000000000000000000000000000000000000',
+      'd8dA6BF26964aF9D7eEd9e03E53415D37aA96045',
+      '0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045',
+      '0x0000000000000000000000000000000000000000',
+    ])('returns true for a valid prefixed hex address', (hexString) => {
+      expect(isValidHexAddress(hexString)).toBe(true);
+    });
+
+    it.each([
+      '0000000000000000000000000000000000000000',
+      'd8dA6BF26964aF9D7eEd9e03E53415D37aA96045',
+    ])('returns true for a valid non-prefixed hex address', (hexString) => {
+      expect(isValidHexAddress(hexString)).toBe(true);
+    });
+  });
+
+  describe('with allowNonPrefixed option set to false', () => {
+    it.each([
+      '0000000000000000000000000000000000000000',
+      'd8dA6BF26964aF9D7eEd9e03E53415D37aA96045',
+    ])('returns false for a valid non-prefixed hex address', (hexString) => {
+      expect(isValidHexAddress(hexString, { allowNonPrefixed: false })).toBe(
+        false,
+      );
+    });
+  });
+
+  it.each([
+    '12345g',
+    '1234567890abcdefg',
+    '1234567890abcdefG',
+    '1234567890abcdefABCDEFg',
+    '1234567890abcdefABCDEF1234567890abcdefABCDEFg',
+    '0x',
+    '0x0',
+    '0x12345g',
+    '0x1234567890abcdefg',
+    '0x1234567890abcdefG',
+    '0x1234567890abcdefABCDEFg',
+    '0x1234567890abcdefABCDEF1234567890abcdefABCDEFg',
+  ])('returns false for an invalid hex address', (hexString) => {
+    expect(isValidHexAddress(hexString)).toBe(false);
+  });
+});
+
 describe('add0x', () => {
   it('adds a 0x-prefix to a string', () => {
     expect(add0x('12345')).toBe('0x12345');

src/hex.ts

@@ -55,6 +55,30 @@ export function assertIsStrictHexString(value: unknown): asserts value is Hex {
   );
 }
 
+/**
+ * Validates that the input is a hex address. This utility by default
+ * will return true for hex strings that meet the length requirement
+ * of a hex address, but are not necessarily prefixed with `0x`.
+ *
+ * @param possibleAddress - Input parameter to check against.
+ * @param options - The validation options.
+ * @param options.allowNonPrefixed - If true will allow addresses without `0x` prefix.`
+ * @returns Whether or not the input is a valid hex address.
+ */
+export function isValidHexAddress(
+  possibleAddress: string,
+  { allowNonPrefixed = true } = {},
+) {
+  const addressToCheck = allowNonPrefixed
+    ? add0x(possibleAddress)
+    : possibleAddress;
+  if (!isHexString(addressToCheck)) {
+    return false;
+  }
+
+  return is(addressToCheck, pattern(string(), /^0x[0-9a-fA-F]{40}$/u));
+}
+
 /**
  * Add the `0x`-prefix to a hexadecimal string. If the string already has the
  * prefix, it is returned as-is.