stripPrefix adjustment

packages/util/src/hex/stripPrefix.spec.ts

@@ -22,9 +22,21 @@ describe('hexStripPrefix', (): void => {
     ).toEqual('1223');
   });
 
+  it('strips the prefix from hex strings (non 2 lnegth)', (): void => {
+    expect(
+      hexStripPrefix('0x123')
+    ).toEqual('123');
+  });
+
   it('returns un-prefixed hex as-is', (): void => {
     expect(
       hexStripPrefix('abcd1223')
     ).toEqual('abcd1223');
   });
+
+  it('throws when invalid hex', (): void => {
+    expect(
+      () => hexStripPrefix('0x0x01ab')
+    ).toThrow(/Expected hex value to convert/);
+  });
 });

packages/util/src/hex/stripPrefix.ts

@@ -1,6 +1,8 @@
 // Copyright 2017-2021 @polkadot/util authors & contributors
 // SPDX-License-Identifier: Apache-2.0
 
+import { REGEX_HEX_NOPREFIX_IGNORE, REGEX_HEX_PREFIXED_IGNORE } from '../is/hex';
+
 /**
  * @name hexStripPrefix
  * @summary Strips any leading `0x` prefix.
@@ -16,9 +18,13 @@
  * ```
  */
 export function hexStripPrefix (value?: string | null): string {
-  return (!value || value === '0x')
-    ? ''
-    : value.startsWith('0x')
-      ? value.substr(2)
-      : value;
+  if (!value || value === '0x') {
+    return '';
+  } else if (REGEX_HEX_PREFIXED_IGNORE.test(value)) {
+    return value.substr(2);
+  } else if (REGEX_HEX_NOPREFIX_IGNORE.test(value)) {
+    return value;
+  }
+
+  throw new Error(`Expected hex value to convert, found '${value}'`);
 }

packages/util/src/is/hex.ts

@@ -7,7 +7,9 @@ export const REGEX_HEX_PREFIXED = /^0x([\da-fA-F]{2})+$/;
 
 export const REGEX_HEX_NOPREFIX = /^([\da-fA-F]{2})+$/;
 
-const REGEX_HEX_PREFIXED_IGNORE = /^0x[\da-fA-F]+$/;
+export const REGEX_HEX_PREFIXED_IGNORE = /^0x[\da-fA-F]+$/;
+
+export const REGEX_HEX_NOPREFIX_IGNORE = /^[\da-fA-F]+$/;
 
 /**
  * @name isHex