feat: add utils functions to handle ERC-721 URNs (#172)

etc/urn-resolver.api.md

@@ -110,6 +110,15 @@ export type EntityV3Asset = {
     baseUrl?: string;
 };
 
+// @public
+export function getTokenIdAndAssetUrn(completeUrn: string): {
+    assetUrn: string;
+    tokenId: string;
+};
+
+// @public
+export function isExtendedUrn(asset: DecentralandAssetIdentifier): boolean;
+
 // @public (undocumented)
 export namespace LandUtils {
     // (undocumented)

src/collection-items-utils.ts

@@ -0,0 +1,20 @@
+import { DecentralandAssetIdentifier } from './types'
+
+/**
+ * Checks if the URN follows the standard ERC-721 by having the tokenId identifier at the end
+ * @public
+ */
+export function isExtendedUrn(asset: DecentralandAssetIdentifier): boolean {
+  return ['blockchain-collection-v1-item', 'blockchain-collection-v2-item'].includes(asset.type)
+}
+
+/**
+ * Takes an URN adhering to the ERC-721 standard and resolves both its asset URN and token identity
+ * WARNING: it assumes the URN received follows the ERC-721 standard and that its last part refers to the token id
+ * @public
+ */
+export function getTokenIdAndAssetUrn(completeUrn: string): { assetUrn: string; tokenId: string } {
+  const lastColonIndex = completeUrn.lastIndexOf(':')
+  const urnValue = completeUrn.slice(0, lastColonIndex)
+  return { assetUrn: urnValue, tokenId: completeUrn.slice(lastColonIndex + 1) }
+}

src/index.ts

@@ -4,6 +4,8 @@ export * from './types'
 export { LandUtils } from './land-utils'
 import { resolveContentUrl, ResolversOptions } from './content-url-resolver'
 export { resolveContentUrl, ResolversOptions }
+export { isExtendedUrn, getTokenIdAndAssetUrn } from './collection-items-utils'
+
 /**
  * Function that parses an URN and returns a DecentralandAssetIdentifier record or null.
  * @public

src/resolvers.ts

@@ -29,23 +29,22 @@ export const resolvers: RouteMap<DecentralandAssetIdentifier> = {
   // collections v1 asset (by contract)
   'decentraland:{network}:collections-v1:{contract(0x[a-fA-F0-9]+)}:{name}': resolveCollectionV1Asset,
   // collections v1 item (by asset name and token id)
-  'decentraland:{network}:collections-v1:{contract(0x[a-fA-F0-9]+)}:{name}:{tokenId([0-9]+)}':
-    resolveCollectionV1AssetTokenId,
+  'decentraland:{network}:collections-v1:{contract(0x[a-fA-F0-9]+)}:{name}:{tokenId([0-9]+)}': resolveCollectionV1Item,
   // collections v1 asset (by name)
   'decentraland:{network}:collections-v1:{collectionName}:{name}': resolveCollectionV1AssetByCollectionName,
   // collections v1 item (by asset name and token id)
   'decentraland:{network}:collections-v1:{collectionName}:{name}:{tokenId([0-9]+)}':
-    resolveCollectionV1AssetByCollectionNameTokenId,
+    resolveCollectionV1ItemByCollectionName,
   // collections v2 asset (hex)
   'decentraland:{network}:collections-v2:{contract(0x[a-fA-F0-9]+)}:{id(0x[a-fA-F0-9]+)}': resolveCollectionV2Asset,
   // collections v2 item (by collection hex and token id)
   'decentraland:{network}:collections-v2:{contract(0x[a-fA-F0-9]+)}:{id(0x[a-fA-F0-9]+)}:{tokenId([0-9]+)}':
-    resolveCollectionV2AssetTokenId,
+    resolveCollectionV2Item,
   // collections v2 asset (id)
   'decentraland:{network}:collections-v2:{contract(0x[a-fA-F0-9]+)}:{id([0-9]+)}': resolveCollectionV2Asset,
   // collections v2 item (by collection asset and token id)
   'decentraland:{network}:collections-v2:{contract(0x[a-fA-F0-9]+)}:{id([0-9]+)}:{tokenId([0-9]+)}':
-    resolveCollectionV2AssetTokenId,
+    resolveCollectionV2Item,
   // collections v1 (by contract)
   'decentraland:{network}:collections-v1:{contract(0x[a-fA-F0-9]+)}': resolveCollectionV1,
   // collections v1 (by name)
@@ -234,7 +233,7 @@ export async function resolveCollectionV1AssetByCollectionName(
   }
 }
 
-export async function resolveCollectionV1AssetByCollectionNameTokenId(
+export async function resolveCollectionV1ItemByCollectionName(
   uri: URL,
   groups: Record<'network' | 'collectionName' | 'name' | 'tokenId', string>
 ): Promise<BlockchainCollectionV1Item | undefined> {
@@ -283,7 +282,7 @@ export async function resolveCollectionV1Asset(
   return result
 }
 
-export async function resolveCollectionV1AssetTokenId(
+export async function resolveCollectionV1Item(
   uri: URL,
   groups: Record<'network' | 'contract' | 'name' | 'tokenId', string>
 ): Promise<BlockchainCollectionV1Item | undefined> {
@@ -335,7 +334,7 @@ export async function resolveCollectionV2Asset(
   return result
 }
 
-export async function resolveCollectionV2AssetTokenId(
+export async function resolveCollectionV2Item(
   uri: URL,
   groups: Record<'network' | 'contract' | 'id' | 'tokenId', string>
 ): Promise<BlockchainCollectionV2Item | undefined> {

src/types.ts

@@ -70,6 +70,9 @@ export type BlockchainCollectionV1Asset = {
  */
 export type BlockchainCollectionV1Item = Omit<BlockchainCollectionV1Asset, 'type'> & {
   type: 'blockchain-collection-v1-item'
+  /**
+   * Asset identifier for ERC721 contracts
+   */
   tokenId: string
 }
 
@@ -113,6 +116,9 @@ export type BlockchainCollectionV2Asset = BaseBlockchainAsset & {
  */
 export type BlockchainCollectionV2Item = Omit<BlockchainCollectionV2Asset, 'type'> & {
   type: 'blockchain-collection-v2-item'
+  /**
+   * Asset identifier for ERC721 contracts
+   */
   tokenId: string
 }