feat: add support for custom signer (#71)

* feat: add support for custom signer

* typos

* Clarification

* Fix

Author: sunwrobert

README.md

@@ -34,14 +34,48 @@ npm install --save @opensea/seaport-js
 
 Instantiate your instance of seaport using your ethers provider:
 
+### Examples
+
+#### Through a browser provider (i.e. Metamask)
+
 ```js
 import { Seaport } from "@opensea/seaport-js";
+import { ethers } from "ethers";
 
-const provider = ethers.getDefaultProvider();
+const provider = new ethers.providers.Web3Provider(window.ethereum);
 
 const seaport = new Seaport(provider);
 ```
 
+#### Through a RPC Provider (i.e. Alchemy)
+
+```js
+import { Seaport } from "@opensea/seaport-js";
+import { ethers } from "ethers";
+
+const provider = new ethers.provider.JsonRpcProvider(
+  "https://<network>.alchemyapi.io/v2/YOUR-API-KEY"
+);
+
+const seaport = new Seaport(provider);
+```
+
+#### With custom signer
+
+```js
+import { Seaport } from "@opensea/seaport-js";
+import { ethers } from "ethers";
+
+// Provider must be provided to the signer when supplying a custom signer
+const provider = new ethers.provider.JsonRpcProvider(
+  "https://<network>.alchemyapi.io/v2/YOUR-API-KEY"
+);
+
+const signer = new ethers.Wallet("YOUR_PK", provider);
+
+const seaport = new Seaport(signer);
+```
+
 Look at the relevant definitions in `seaport.ts` in order to see the different functionality this library offers.
 
 ### Use Cases

src/seaport.ts

@@ -36,6 +36,7 @@ import type {
   ContractMethodReturnType,
   MatchOrdersFulfillment,
   SeaportContract,
+  Signer,
 } from "./types";
 import { getApprovalActions } from "./utils/approval";
 import {
@@ -65,7 +66,9 @@ export class Seaport {
   // Provides the raw interface to the contract for flexibility
   public contract: SeaportContract;
 
-  private provider: providers.JsonRpcProvider;
+  private provider: providers.Provider;
+
+  private signer?: Signer;
 
   // Use the multicall provider for reads for batching and performance optimisations
   // NOTE: Do NOT await between sequential requests if you're intending to batch
@@ -80,11 +83,11 @@ export class Seaport {
   readonly OPENSEA_CONDUIT_KEY: string = OPENSEA_CONDUIT_KEY;
 
   /**
-   * @param provider - The provider to use for web3-related calls
+   * @param providerOrSigner - The provider or signer to use for web3-related calls
    * @param considerationConfig - A config to provide flexibility in the usage of Seaport
    */
   public constructor(
-    provider: providers.JsonRpcProvider,
+    providerOrSigner: providers.JsonRpcProvider | Signer,
     {
       overrides,
       // Five minute buffer
@@ -93,8 +96,22 @@ export class Seaport {
       conduitKeyToConduit,
     }: SeaportConfig = {}
   ) {
+    const provider =
+      providerOrSigner instanceof providers.Provider
+        ? providerOrSigner
+        : providerOrSigner.provider;
+
+    if (!provider) {
+      throw new Error(
+        "Either a provider or custom signer with provider must be provided"
+      );
+    }
+
     this.provider = provider;
-    this.multicallProvider = new multicallProviders.MulticallProvider(provider);
+
+    this.multicallProvider = new multicallProviders.MulticallProvider(
+      this.provider
+    );
 
     this.contract = new Contract(
       overrides?.contractAddress ?? CROSS_CHAIN_SEAPORT_ADDRESS,
@@ -115,6 +132,18 @@ export class Seaport {
     this.defaultConduitKey = overrides?.defaultConduitKey ?? NO_CONDUIT;
   }
 
+  private _getSigner(accountAddress?: string): Signer {
+    if (this.signer) {
+      return this.signer;
+    }
+
+    if (!(this.provider instanceof providers.JsonRpcProvider)) {
+      throw new Error("Either signer or a JsonRpcProvider must be provided");
+    }
+
+    return this.provider.getSigner(accountAddress);
+  }
+
   /**
    * Returns the corresponding order type based on whether it allows partial fills and is restricted by zone
    *
@@ -177,7 +206,7 @@ export class Seaport {
     }: CreateOrderInput,
     accountAddress?: string
   ): Promise<OrderUseCase<CreateOrderAction>> {
-    const signer = await this.provider.getSigner(accountAddress);
+    const signer = this._getSigner(accountAddress);
     const offerer = await signer.getAddress();
     const offerItems = offer.map(mapInputItemToOfferItem);
     const considerationItems = [
@@ -349,7 +378,7 @@ export class Seaport {
     counter: number,
     accountAddress?: string
   ): Promise<string> {
-    const signer = this.provider.getSigner(accountAddress);
+    const signer = this._getSigner(accountAddress);
 
     const domainData = await this._getDomainData();
 
@@ -379,7 +408,7 @@ export class Seaport {
     orders: OrderComponents[],
     accountAddress?: string
   ): TransactionMethods<ContractMethodReturnType<SeaportContract, "cancel">> {
-    const signer = this.provider.getSigner(accountAddress);
+    const signer = this._getSigner(accountAddress);
 
     return getTransactionMethods(this.contract.connect(signer), "cancel", [
       orders,
@@ -396,7 +425,7 @@ export class Seaport {
   ): TransactionMethods<
     ContractMethodReturnType<SeaportContract, "incrementCounter">
   > {
-    const signer = this.provider.getSigner(offerer);
+    const signer = this._getSigner(offerer);
 
     return getTransactionMethods(
       this.contract.connect(signer),
@@ -416,7 +445,7 @@ export class Seaport {
     orders: Order[],
     accountAddress?: string
   ): TransactionMethods<ContractMethodReturnType<SeaportContract, "validate">> {
-    const signer = this.provider.getSigner(accountAddress);
+    const signer = this._getSigner(accountAddress);
 
     return getTransactionMethods(this.contract.connect(signer), "validate", [
       orders,
@@ -610,7 +639,7 @@ export class Seaport {
     const { parameters: orderParameters } = order;
     const { offerer, offer, consideration } = orderParameters;
 
-    const fulfiller = await this.provider.getSigner(accountAddress);
+    const fulfiller = this._getSigner(accountAddress);
 
     const fulfillerAddress = await fulfiller.getAddress();
 
@@ -744,7 +773,7 @@ export class Seaport {
     conduitKey?: string;
     recipientAddress?: string;
   }) {
-    const fulfiller = await this.provider.getSigner(accountAddress);
+    const fulfiller = this._getSigner(accountAddress);
 
     const fulfillerAddress = await fulfiller.getAddress();
 
@@ -859,7 +888,7 @@ export class Seaport {
   }): TransactionMethods<
     ContractMethodReturnType<SeaportContract, "matchOrders">
   > {
-    const signer = this.provider.getSigner(accountAddress);
+    const signer = this._getSigner(accountAddress);
 
     return getTransactionMethods(this.contract.connect(signer), "matchOrders", [
       orders,

src/types.ts

@@ -5,8 +5,10 @@ import type {
 import {
   BigNumber,
   BigNumberish,
+  BytesLike,
   Contract,
   ContractTransaction,
+  ethers,
   Overrides,
   PayableOverrides,
   PopulatedTransaction,
@@ -32,6 +34,28 @@ export type SeaportConfig = {
   };
 };
 
+type TypedDataDomain = {
+  name?: string;
+  version?: string;
+  chainId?: BigNumberish;
+  verifyingContract?: string;
+  salt?: BytesLike;
+};
+
+type TypedDataField = {
+  name: string;
+  type: string;
+};
+
+// Temporary until TypedDataSigner is added in ethers (in v6)
+export type Signer = ethers.Signer & {
+  _signTypedData(
+    domain: TypedDataDomain,
+    types: Record<string, Array<TypedDataField>>,
+    value: Record<string, any>
+  ): Promise<string>;
+};
+
 export type OfferItem = {
   itemType: ItemType;
   token: string;

src/utils/approval.ts

@@ -1,5 +1,5 @@
 import { providers as multicallProviders } from "@0xsequence/multicall";
-import { BigNumber, Contract, providers } from "ethers";
+import { BigNumber, Contract, Signer } from "ethers";
 import { ERC20ABI } from "../abi/ERC20";
 import { ERC721ABI } from "../abi/ERC721";
 import { ItemType, MAX_INT } from "../constants";
@@ -46,7 +46,7 @@ export const approvedItemAmount = async (
  */
 export function getApprovalActions(
   insufficientApprovals: InsufficientApprovals,
-  signer: providers.JsonRpcSigner
+  signer: Signer
 ): Promise<ApprovalAction[]> {
   return Promise.all(
     insufficientApprovals

src/utils/fulfill.ts

@@ -3,7 +3,7 @@ import {
   BigNumberish,
   ContractTransaction,
   ethers,
-  providers,
+  Signer,
 } from "ethers";
 import type {
   Seaport as SeaportContract,
@@ -197,7 +197,7 @@ export async function fulfillBasicOrder({
   timeBasedItemParams: TimeBasedItemParams;
   offererOperator: string;
   fulfillerOperator: string;
-  signer: providers.JsonRpcSigner;
+  signer: Signer;
   tips?: ConsiderationItem[];
   conduitKey: string;
 }): Promise<
@@ -340,7 +340,7 @@ export async function fulfillStandardOrder({
   conduitKey: string;
   recipientAddress: string;
   timeBasedItemParams: TimeBasedItemParams;
-  signer: providers.JsonRpcSigner;
+  signer: Signer;
 }): Promise<
   OrderUseCase<
     ExchangeAction<
@@ -530,7 +530,7 @@ export async function fulfillAvailableOrders({
   currentBlockTimestamp: number;
   ascendingAmountTimestampBuffer: number;
   conduitKey: string;
-  signer: providers.JsonRpcSigner;
+  signer: Signer;
   recipientAddress: string;
 }): Promise<
   OrderUseCase<