From ab8bb292d6a2065919d4ac9616ad501968e235d4 Mon Sep 17 00:00:00 2001
From: Martynas Kazlauskas <martynas.kazlauskas@iohk.io>
Date: Mon, 7 Aug 2023 12:31:22 +0300
Subject: [PATCH] feat(projection): ignore burn transactions when projecting
 cip25 metadata

https://github.com/cardano-foundation/CIPs/pull/527
---
 .../src/operators/Mappers/withNftMetadata.ts         |  3 ++-
 .../test/operators/Mappers/withNftMetadata.test.ts   | 12 +++++++++++-
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/packages/projection/src/operators/Mappers/withNftMetadata.ts b/packages/projection/src/operators/Mappers/withNftMetadata.ts
index ae6ea7e0de8..259cf166320 100644
--- a/packages/projection/src/operators/Mappers/withNftMetadata.ts
+++ b/packages/projection/src/operators/Mappers/withNftMetadata.ts
@@ -30,7 +30,8 @@ const getNftMetadataFromCip67 = ({ cip67 }: WithCIP67, logger: Logger) =>
   );
 
 const getNftMetadataFromCip25 = ({ mint }: WithMint, logger: Logger) =>
-  mint.map(({ assetId, txMetadata, policyId, assetName }): ProjectedNftMetadata | null => {
+  mint.map(({ assetId, txMetadata, policyId, assetName, quantity }): ProjectedNftMetadata | null => {
+    if (quantity < 1n) return null;
     const nftMetadata = Asset.NftMetadata.fromMetadatum({ name: assetName, policyId }, txMetadata, logger);
 
     if (!nftMetadata) return null;
diff --git a/packages/projection/test/operators/Mappers/withNftMetadata.test.ts b/packages/projection/test/operators/Mappers/withNftMetadata.test.ts
index 7a2369e5931..b5bdfaa140e 100644
--- a/packages/projection/test/operators/Mappers/withNftMetadata.test.ts
+++ b/packages/projection/test/operators/Mappers/withNftMetadata.test.ts
@@ -53,6 +53,7 @@ const datumNftmetadata = {
 describe('withNftMetadata', () => {
   const assetId1 = Cardano.AssetId('7d878696b149b529807aa01b8e20785e0a0d470c32c13f53f08a55e344455630303032');
   const assetId2 = Cardano.AssetId('7d878696b149b529807aa01b8e20785e0a0d470c32c13f53f08a55e344455638393230');
+  const assetId3 = Cardano.AssetId('7d878696b149b529807aa01b8e20785e0a0d470c32c13f53f08a55e344455638393233');
   const otherProperties1 = new Map([
     ['Background', 'Ocean'],
     ['Body', 'Pale'],
@@ -97,6 +98,14 @@ describe('withNftMetadata', () => {
                   ['name', 'DEV 0002']
                 ])
               ],
+              [
+                Buffer.from(Cardano.AssetId.getAssetName(assetId3), 'hex').toString('utf8'),
+                new Map([
+                  ['image', 'ipfs://QmWmB37VZ9uc2cVe2fG31Xqjxw5VbUu4DMLkGt9LW6z7Up'],
+                  ['mediaType', 'image/jpeg'],
+                  ['name', 'Burned']
+                ])
+              ],
               [
                 'DEV8920',
                 new Map([
@@ -121,7 +130,8 @@ describe('withNftMetadata', () => {
           body: {
             mint: new Map([
               [assetId1, 1n],
-              [assetId2, 1n]
+              [assetId2, 1n],
+              [assetId3, -1n]
             ])
           }
         }