Allow null in assets handlers response

Author: GuillaumeRx

packages/snaps-controllers/src/snaps/SnapController.ts

@@ -3689,7 +3689,7 @@ export class SnapController extends BaseController<
     const { assets: requestedAssets } = requestedParams;
 
     const filteredAssets = Object.keys(assets).reduce<
-      Record<CaipAssetType, FungibleAssetMetadata>
+      Record<CaipAssetType, FungibleAssetMetadata | null>
     >((accumulator, assetType) => {
       const castAssetType = assetType as CaipAssetType;
       const isValid =

packages/snaps-sdk/src/types/handlers/assets-conversion.ts

@@ -40,11 +40,11 @@ export type OnAssetsConversionHandler = (
 /**
  * The response from the conversion query, containing rates about each requested asset pair.
  *
- * @property conversionRates - A nested object with two CAIP-19 keys that contains a conversion rate between the two keys.
+ * @property conversionRates - A nested object with two CAIP-19 keys that contains a conversion rate or null between the two keys.
  */
 export type OnAssetsConversionResponse = {
   conversionRates: Record<
     CaipAssetType,
-    Record<CaipAssetType, AssetConversion>
+    Record<CaipAssetType, AssetConversion | null>
   >;
 };

packages/snaps-sdk/src/types/handlers/assets-lookup.ts

@@ -68,8 +68,8 @@ export type OnAssetsLookupHandler = (
 /**
  * The response from the query, containing metadata about each requested asset.
  *
- * @property assets - An object containing a mapping between the CAIP-19 key and a metadata object.
+ * @property assets - An object containing a mapping between the CAIP-19 key and a metadata object or null.
  */
 export type OnAssetsLookupResponse = {
-  assets: Record<CaipAssetType, FungibleAssetMetadata>;
+  assets: Record<CaipAssetType, FungibleAssetMetadata | null>;
 };