feat(fusion-order): add isExclusiveResolver method (#75)

src/api/quoter/quote/quote.ts

@@ -6,7 +6,6 @@ import {Preset} from '../preset'
 import {AuctionWhitelistItem, FusionOrder} from '../../../fusion-order'
 import {QuoterRequest} from '../quoter.request'
 import {bpsToRatioFormat} from '../../../sdk'
-import {now} from '../../../utils/time'
 
 export class Quote {
     /**
@@ -132,7 +131,7 @@ export class Quote {
 
                 return {
                     address: resolver,
-                    allowFrom: isExclusive ? now() : auctionStartTime
+                    allowFrom: isExclusive ? 0n : auctionStartTime
                 }
             })
         }

src/fusion-order/fusion-order.ts

@@ -411,4 +411,13 @@ export class FusionOrder {
             this.makingAmount
         )
     }
+
+    /**
+     * Check if `wallet` can fill order before other
+     */
+    public isExclusiveResolver(wallet: Address): boolean {
+        return this.fusionExtension.postInteractionData.isExclusiveResolver(
+            wallet
+        )
+    }
 }

src/fusion-order/settlement-post-interaction-data/settlement-post-interaction-data.ts

@@ -200,6 +200,22 @@ export class SettlementPostInteractionData {
 
         return false
     }
+
+    public isExclusiveResolver(wallet: Address): boolean {
+        const addressHalf = wallet.toString().slice(-20)
+
+        // only one resolver, so check if it is the passed address
+        if (this.whitelist.length === 1) {
+            return addressHalf === this.whitelist[0].addressHalf
+        }
+
+        // more than 1 address can fill at the same time, no exclusivity
+        if (this.whitelist[0].delay === this.whitelist[1].delay) {
+            return false
+        }
+
+        return addressHalf === this.whitelist[0].addressHalf
+    }
 }
 
 type WhitelistItem = {