From 3e6213a3acf3b5d16b79447f87a7029f1020d7b3 Mon Sep 17 00:00:00 2001
From: CJ42 <cavallerajean@gmail.com>
Date: Thu, 25 Apr 2024 18:02:04 +0100
Subject: [PATCH] refactor: improve code for `Literal` hex for `valueContent`

---
 src/lib/encoder.ts    | 18 ++++++++++++------
 src/lib/utils.test.ts |  2 +-
 src/lib/utils.ts      | 16 +++++++++++-----
 3 files changed, 24 insertions(+), 12 deletions(-)

diff --git a/src/lib/encoder.ts b/src/lib/encoder.ts
index 74f30891..bed0761d 100644
--- a/src/lib/encoder.ts
+++ b/src/lib/encoder.ts
@@ -57,7 +57,8 @@ import {
   countNumberOfBytes,
   isValidUintSize,
   countSignificantBits,
-  isValidBytesSize,
+  isValidByteSize,
+  isValueContentLiteralHex,
 } from './utils';
 import { ERC725JSONSchemaValueType } from '../types/ERC725JSONSchema';
 
@@ -602,7 +603,7 @@ const valueTypeEncodingMap = (
     case `bytes${bytesLength}`:
       return {
         encode: (value: string | number) => {
-          if (!isValidBytesSize(bytesLength as number)) {
+          if (!isValidByteSize(bytesLength as number)) {
             throw new Error(
               `Can't encode ${value} as ${type}. Invalid \`bytesN\` provided. Expected a \`N\` value for bytesN between 1 and 32.`,
             );
@@ -822,7 +823,7 @@ export const valueContentEncodingMap = (
             throw new Error(`Value: ${value} is not hex.`);
           }
 
-          if (bytesLength && !isValidBytesSize(bytesLength)) {
+          if (bytesLength && !isValidByteSize(bytesLength)) {
             throw new Error(
               `Provided bytes length: ${bytesLength} for encoding valueContent: ${valueContent} is not valid.`,
             );
@@ -844,7 +845,7 @@ export const valueContentEncodingMap = (
             return null;
           }
 
-          if (bytesLength && !isValidBytesSize(bytesLength)) {
+          if (bytesLength && !isValidByteSize(bytesLength)) {
             console.error(
               `Provided bytes length: ${bytesLength} for encoding valueContent: ${valueContent} is not valid.`,
             );
@@ -981,8 +982,13 @@ export function decodeValueContent(
   valueContent: string,
   value: string,
 ): string | URLDataWithHash | number | boolean | null {
-  if (valueContent.slice(0, 2) === '0x') {
-    return valueContent === value ? value : null;
+  if (isValueContentLiteralHex(valueContent)) {
+    if (valueContent.toLowerCase() != value) {
+      throw new Error(
+        `Could not decode value content: the value ${value} does not match the Hex Literal ${valueContent} defined in the \`valueContent\` part of the schema`,
+      );
+    }
+    return valueContent;
   }
 
   if (value == null || value === '0x') {
diff --git a/src/lib/utils.test.ts b/src/lib/utils.test.ts
index 088dfe19..3f994707 100644
--- a/src/lib/utils.test.ts
+++ b/src/lib/utils.test.ts
@@ -378,7 +378,7 @@ describe('utils', () => {
         valueContent: '0xc9aaAE3201F40fd0fF04D9c885769d8256A456ab',
         valueType: 'bytes',
         decodedValue: '0xc9aaAE3201F40fd0fF04D9c885769d8256A456ab',
-        encodedValue: '0xc9aaAE3201F40fd0fF04D9c885769d8256A456ab',
+        encodedValue: '0xc9aaae3201f40fd0ff04d9c885769d8256a456ab', // encoded hex is always lower case
       },
     ];
 
diff --git a/src/lib/utils.ts b/src/lib/utils.ts
index e22545a2..e8e49baf 100644
--- a/src/lib/utils.ts
+++ b/src/lib/utils.ts
@@ -23,6 +23,7 @@ import {
   checkAddressChecksum,
   hexToBytes,
   isAddress,
+  isHexStrict,
   leftPad,
   numberToHex,
   padLeft,
@@ -61,10 +62,6 @@ import { EncodeDataInput } from '../types/decodeData';
 import { GetDataDynamicKey } from '../types/GetData';
 import { isValidTuple } from './decodeData';
 
-function isValueContentLiteralHex(valueContent: string): boolean {
-  return valueContent.slice(0, 2) === '0x';
-}
-
 /**
  *
  * @param {string} valueContent as per ERC725Schema definition
@@ -823,6 +820,15 @@ export function isValidUintSize(bitSize: number) {
  *
  * @param bytesSize the size of the fixed size bytes value
  */
-export function isValidBytesSize(bytesSize: number) {
+export function isValidByteSize(bytesSize: number) {
   return bytesSize >= 1 && bytesSize <= 32;
 }
+
+/**
+ * @dev Check if the `valueContent` in a schema is defined as an hex literal string
+ * @param valueContent The valueContent part of a schema
+ * @returns true or false
+ */
+export function isValueContentLiteralHex(valueContent: string): boolean {
+  return isHexStrict(valueContent);
+}