Use satoshi amount while searching wallet for redemption (#740)

The `RedemptionsService.requestRedemption` function takes an amount in the TBTC token precision (1e18). However, the `findWalletForRedemption` method called to find a wallet for redemption expects an amount in the sathoshi precision (1e8). There is a missing conversion which we are adding in this changeset.
keep-network · Nov 7, 2023 · ff7dd26 · ff7dd26
2 parents 8852fab + 17455e5
commit ff7dd26
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Showing 4 changed files with 18 additions and 7 deletions.
diff --git a/typescript/api-reference/classes/RedemptionsService.md b/typescript/api-reference/classes/RedemptionsService.md
@@ -90,7 +90,7 @@ Promise holding the wallet main UTXO or undefined value.
 
 #### Defined in
 
-[services/redemptions/redemptions-service.ts:215](https://github.com/keep-network/tbtc-v2/blob/main/typescript/src/services/redemptions/redemptions-service.ts#L215)
+[services/redemptions/redemptions-service.ts:225](https://github.com/keep-network/tbtc-v2/blob/main/typescript/src/services/redemptions/redemptions-service.ts#L225)
 
 ___
 
@@ -116,7 +116,7 @@ Promise with the wallet details needed to request a redemption.
 
 #### Defined in
 
-[services/redemptions/redemptions-service.ts:96](https://github.com/keep-network/tbtc-v2/blob/main/typescript/src/services/redemptions/redemptions-service.ts#L96)
+[services/redemptions/redemptions-service.ts:106](https://github.com/keep-network/tbtc-v2/blob/main/typescript/src/services/redemptions/redemptions-service.ts#L106)
 
 ___
 
@@ -147,7 +147,7 @@ Throws an error if no redemption request exists for the given
 
 #### Defined in
 
-[services/redemptions/redemptions-service.ts:327](https://github.com/keep-network/tbtc-v2/blob/main/typescript/src/services/redemptions/redemptions-service.ts#L327)
+[services/redemptions/redemptions-service.ts:337](https://github.com/keep-network/tbtc-v2/blob/main/typescript/src/services/redemptions/redemptions-service.ts#L337)
 
 ___
 

diff --git a/typescript/src/services/redemptions/redemptions-service.ts b/typescript/src/services/redemptions/redemptions-service.ts
@@ -67,9 +67,19 @@ export class RedemptionsService {
       throw new Error("Redeemer output script must be of standard type")
     }
 
+    const amountToSatoshi = (value: BigNumber): BigNumber => {
+      const satoshiMultiplier = BigNumber.from(1e10)
+      const remainder = value.mod(satoshiMultiplier)
+      const convertibleAmount = amount.sub(remainder)
+      return convertibleAmount.div(satoshiMultiplier)
+    }
+
+    // The findWalletForRedemption operates on satoshi amount precision (1e8)
+    // while the amount parameter is TBTC token precision (1e18). We need to
+    // convert the amount to get proper results.
     const { walletPublicKey, mainUtxo } = await this.findWalletForRedemption(
       redeemerOutputScript,
-      amount
+      amountToSatoshi(amount)
     )
 
     const txHash = await this.tbtcContracts.tbtcToken.requestRedemption(

diff --git a/typescript/test/services/redemptions.test.ts b/typescript/test/services/redemptions.test.ts
@@ -43,8 +43,9 @@ describe("Redemptions", () => {
       }
       const redeemerOutputScript =
         data.pendingRedemptions[0].pendingRedemption.redeemerOutputScript
+      // Use amount in TBTC token precision (1e18)
       const amount =
-        data.pendingRedemptions[0].pendingRedemption.requestedAmount
+        data.pendingRedemptions[0].pendingRedemption.requestedAmount.mul(1e10)
 
       let tbtcContracts: MockTBTCContracts
       let bitcoinClient: MockBitcoinClient
@@ -129,7 +130,7 @@ describe("Redemptions", () => {
           walletPublicKey,
           mainUtxo,
           redeemerOutputScript,
-          amount,
+          amount: amount.div(1e10),
         })
       })
     })

diff --git a/typescript/test/utils/mock-tbtc-token.ts b/typescript/test/utils/mock-tbtc-token.ts
@@ -32,7 +32,7 @@ export class MockTBTCToken implements TBTCToken {
       walletPublicKey,
       mainUtxo,
       redeemerOutputScript,
-      amount,
+      amount: amount.div(1e10), // Store amount in satoshi.
     })
 
     return Hex.from(