fix(core): add option to remove invisible characters from asset name

input-output-hk · May 9, 2024 · a47beba · a47beba
1 parent 898a821
commit a47beba
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Showing 3 changed files with 20 additions and 6 deletions.
diff --git a/packages/core/src/Asset/NftMetadata/fromMetadatum.ts b/packages/core/src/Asset/NftMetadata/fromMetadatum.ts
@@ -98,12 +98,18 @@ const getAssetMetadata = (policy: Cardano.MetadatumMap, assetName: Cardano.Asset
   );
 
 type AssetIdParts = Pick<AssetInfo, 'policyId' | 'name'>;
-const getName = (assetMetadata: Cardano.MetadatumMap, version: string, asset: AssetIdParts, logger: Logger) => {
+const getName = (
+  assetMetadata: Cardano.MetadatumMap,
+  version: string,
+  asset: AssetIdParts,
+  logger: Logger,
+  stripInvisibleCharacters = false
+) => {
   const name = asString(assetMetadata.get('name'));
   if (name) return name;
   if (version === '1.0') {
     try {
-      return AssetName.toUTF8(asset.name);
+      return AssetName.toUTF8(asset.name, stripInvisibleCharacters);
     } catch (error) {
       logger.warn(error);
     }
@@ -143,7 +149,7 @@ export const fromMetadatum = (
   if (!version) return null;
   const assetMetadata = getAssetMetadata(policy, asset.name);
   if (!assetMetadata) return null;
-  const name = getName(assetMetadata, version, asset, logger);
+  const name = getName(assetMetadata, version, asset, logger, true);
   const image = metadatumToString(assetMetadata.get('image'));
   const assetId = Cardano.AssetId.fromParts(asset.policyId, asset.name);
 

diff --git a/packages/core/src/Cardano/types/Asset.ts b/packages/core/src/Cardano/types/Asset.ts
@@ -18,9 +18,14 @@ export const AssetName = (value: string): AssetName => {
 };
 
 const utf8Decoder = new TextDecoder('utf8', { fatal: true });
-AssetName.toUTF8 = (assetName: AssetName) => {
+AssetName.toUTF8 = (assetName: AssetName, stripInvisibleCharacters = false) => {
+  const assetNameBuffer = Buffer.from(assetName, 'hex');
   try {
-    return utf8Decoder.decode(Buffer.from(assetName, 'hex'));
+    if (stripInvisibleCharacters) {
+      // 'invisible' control characters are valid utf8, but we don't want to use them, strip them out
+      return utf8Decoder.decode(assetNameBuffer.filter((v) => v > 31));
+    }
+    return utf8Decoder.decode(assetNameBuffer);
   } catch (error) {
     throw new InvalidStringError(`Cannot convert AssetName '${assetName}' to UTF8`, error);
   }

diff --git a/packages/core/test/Cardano/types/Asset.test.ts b/packages/core/test/Cardano/types/Asset.test.ts
@@ -104,13 +104,16 @@ describe('Cardano/types/Asset', () => {
       expect(() => AssetName('0dbe461fb5f981c0d01615332b8666340eb1a692b3034f46bcb5f5e0dbe461abc')).toThrow();
     });
 
-    describe('fromUTF8', () => {
+    describe('toUTF8', () => {
       it('decodes hex string (bytes) to utf8 string', () => {
         expect(AssetName.toUTF8(AssetName('737472'))).toEqual('str');
       });
       it('throws InvalidStringError when it cannot be decoded to utf8', () => {
         expect(() => AssetName.toUTF8(AssetName('e8'))).toThrowError(InvalidStringError);
       });
+      it('strips invisible characters when requested', () => {
+        expect(AssetName.toUTF8(AssetName('100000'), true)).toEqual('');
+      });
     });
   });