Expose past redemption requested events getter (#677)

Refs: keep-network/keep-core#3664

Here we expose the `Bridge.getRedemptionRequestedEvents` method that
allows fetching past redemption requested events from the `Bridge`
contract.

typescript/src/bitcoin.ts

@@ -639,3 +639,43 @@ export function createAddressFromOutputScript(
  .getAddress()
  ?.toString(toBcoinNetwork(network))
 }
+
+/**
+ * Reads the leading compact size uint from the provided variable length data.
+ *
+ * WARNING: CURRENTLY, THIS FUNCTION SUPPORTS ONLY 1-BYTE COMPACT SIZE UINTS
+ * AND WILL THROW ON COMPACT SIZE UINTS OF DIFFERENT BYTE LENGTH.
+ *
+ * @param varLenData Variable length data preceded by a compact size uint.
+ * @returns An object holding the value of the compact size uint along with the
+ * compact size uint byte length.
+ */
+export function readCompactSizeUint(varLenData: Hex): {
+ value: number
+ byteLength: number
+} {
+ // The varLenData is prefixed with the compact size uint. According to the docs
+ // (https://developer.bitcoin.org/reference/transactions.html#compactsize-unsigned-integers)
+ // a compact size uint can be 1, 3, 5 or 9 bytes. To determine the exact length,
+ // we need to look at the discriminant byte which is always the first byte of
+ // the compact size uint.
+ const discriminant = varLenData.toString().slice(0, 2)
+
+ switch (discriminant) {
+ case "ff":
+ case "fe":
+ case "fd": {
+ throw new Error(
+ "support for 3, 5 and 9 bytes compact size uints is not implemented yet"
+ )
+ }
+ default: {
+ // The discriminant tells the compact size uint is 1 byte. That means
+ // the discriminant represent the value itself.
+ return {
+ value: parseInt(discriminant, 16),
+ byteLength: 1,
+ }
+ }
+ }
+}

typescript/src/chain.ts

@@ -17,7 +17,7 @@ import {
  OptimisticMintingRequestedEvent,
 } from "./optimistic-minting"
 import { Hex } from "./hex"
-import { RedemptionRequest } from "./redemption"
+import { RedemptionRequest, RedemptionRequestedEvent } from "./redemption"
 import {
  DkgResultApprovedEvent,
  DkgResultChallengedEvent,
@@ -260,6 +260,12 @@ export interface Bridge {
  * @returns The hash of the UTXO.
  */
  buildUtxoHash(utxo: UnspentTransactionOutput): Hex
+
+ /**
+ * Get emitted RedemptionRequested events.
+ * @see GetEventsFunction
+ */
+ getRedemptionRequestedEvents: GetEvents.Function<RedemptionRequestedEvent>
 }
 
 /**

typescript/src/ethereum.ts

@@ -27,12 +27,13 @@ import {
  DepositRevealedEvent,
 } from "./deposit"
 import { getEvents, sendWithRetry } from "./ethereum-helpers"
-import { RedemptionRequest } from "./redemption"
+import { RedemptionRequest, RedemptionRequestedEvent } from "./redemption"
 import {
  compressPublicKey,
  computeHash160,
  DecomposedRawTransaction,
  Proof,
+ readCompactSizeUint,
  TransactionHash,
  UnspentTransactionOutput,
 } from "./bitcoin"
@@ -762,6 +763,48 @@ export class Bridge
  )
  )
  }
+
+ // eslint-disable-next-line valid-jsdoc
+ /**
+ * @see {ChainBridge#getDepositRevealedEvents}
+ */
+ async getRedemptionRequestedEvents(
+ options?: GetEvents.Options,
+ ...filterArgs: Array<unknown>
+ ): Promise<RedemptionRequestedEvent[]> {
+ // FIXME: Filtering by indexed walletPubKeyHash field may not work
+ // until https://github.com/ethers-io/ethers.js/pull/4244 is
+ // included in the currently used version of ethers.js.
+ // Ultimately, we should upgrade ethers.js to include that fix.
+ // Short-term, we can workaround the problem as presented in:
+ // https://github.com/threshold-network/token-dashboard/blob/main/src/threshold-ts/tbtc/index.ts#L1041C1-L1093C1
+ const events: EthersEvent[] = await this.getEvents(
+ "RedemptionRequested",
+ options,
+ ...filterArgs
+ )
+
+ return events.map<RedemptionRequestedEvent>((event) => {
+ const prefixedRedeemerOutputScript = Hex.from(
+ event.args!.redeemerOutputScript
+ )
+ const redeemerOutputScript = prefixedRedeemerOutputScript
+ .toString()
+ .slice(readCompactSizeUint(prefixedRedeemerOutputScript).byteLength * 2)
+
+ return {
+ blockNumber: BigNumber.from(event.blockNumber).toNumber(),
+ blockHash: Hex.from(event.blockHash),
+ transactionHash: Hex.from(event.transactionHash),
+ walletPublicKeyHash: Hex.from(event.args!.walletPubKeyHash).toString(),
+ redeemer: new Address(event.args!.redeemer),
+ redeemerOutputScript: redeemerOutputScript,
+ requestedAmount: BigNumber.from(event.args!.requestedAmount),
+ treasuryFee: BigNumber.from(event.args!.treasuryFee),
+ txMaxFee: BigNumber.from(event.args!.txMaxFee),
+ }
+ })
+ }
 }
 
 /**

typescript/src/redemption.ts

@@ -8,7 +8,7 @@ import {
  Client as BitcoinClient,
  TransactionHash,
 } from "./bitcoin"
-import { Bridge, Identifier, TBTCToken } from "./chain"
+import { Bridge, Event, Identifier, TBTCToken } from "./chain"
 import { assembleTransactionProof } from "./proof"
 import { determineWalletMainUtxo, WalletState } from "./wallet"
 import { BitcoinNetwork } from "./bitcoin-network"
@@ -56,6 +56,20 @@ export interface RedemptionRequest {
  requestedAt: number
 }
 
+/**
+ * Represents an event emitted on redemption request.
+ */
+export type RedemptionRequestedEvent = Omit<
+ RedemptionRequest,
+ "requestedAt"
+> & {
+ /**
+ * Public key hash of the wallet that is meant to handle the redemption. Must
+ * be an unprefixed hex string (without 0x prefix).
+ */
+ walletPublicKeyHash: string
+} & Event
+
 /**
  * Requests a redemption of tBTC into BTC.
  * @param walletPublicKey - The Bitcoin public key of the wallet. Must be in the

typescript/test/bitcoin.test.ts

@@ -13,6 +13,7 @@ import {
  targetToDifficulty,
  createOutputScriptFromAddress,
  createAddressFromOutputScript,
+ readCompactSizeUint,
 } from "../src/bitcoin"
 import { calculateDepositRefundLocktime } from "../src/deposit"
 import { BitcoinNetwork } from "../src/bitcoin-network"
@@ -506,4 +507,41 @@ describe("Bitcoin", () => {
  })
  })
  })
+
+ describe("readCompactSizeUint", () => {
+ context("when the compact size uint is 1-byte", () => {
+ it("should return the the uint value and byte length", () => {
+ expect(readCompactSizeUint(Hex.from("bb"))).to.be.eql({
+ value: 187,
+ byteLength: 1,
+ })
+ })
+ })
+
+ context("when the compact size uint is 3-byte", () => {
+ it("should throw", () => {
+ expect(() => readCompactSizeUint(Hex.from("fd0302"))).to.throw(
+ "support for 3, 5 and 9 bytes compact size uints is not implemented yet"
+ )
+ })
+ })
+
+ context("when the compact size uint is 5-byte", () => {
+ it("should throw", () => {
+ expect(() => readCompactSizeUint(Hex.from("fe703a0f00"))).to.throw(
+ "support for 3, 5 and 9 bytes compact size uints is not implemented yet"
+ )
+ })
+ })
+
+ context("when the compact size uint is 9-byte", () => {
+ it("should throw", () => {
+ expect(() => {
+ return readCompactSizeUint(Hex.from("ff57284e56dab40000"))
+ }).to.throw(
+ "support for 3, 5 and 9 bytes compact size uints is not implemented yet"
+ )
+ })
+ })
+ })
 })

typescript/test/utils/mock-bridge.ts

@@ -5,7 +5,7 @@ import {
  UnspentTransactionOutput,
 } from "../../src/bitcoin"
 import { BigNumberish, BigNumber, utils, constants } from "ethers"
-import { RedemptionRequest } from "../redemption"
+import { RedemptionRequest, RedemptionRequestedEvent } from "../redemption"
 import {
  Deposit,
  DepositRevealedEvent,
@@ -365,4 +365,11 @@ export class MockBridge implements Bridge {
  )
  )
  }
+
+ getRedemptionRequestedEvents(
+ options?: GetEvents.Options,
+ ...filterArgs: Array<any>
+ ): Promise<RedemptionRequestedEvent[]> {
+ throw new Error("not implemented")
+ }
 }