Refactor: Preparing for WC Integration (#35)

.eslintrc

@@ -3,27 +3,25 @@
     "browser": true,
     "es2021": true
   },
-  "extends": [
-    "eslint:recommended",
-    "plugin:@typescript-eslint/recommended"
-  ],
+  "extends": ["eslint:recommended", "plugin:@typescript-eslint/recommended"],
   "parser": "@typescript-eslint/parser",
   "parserOptions": {
     "ecmaVersion": "latest",
     "sourceType": "module"
   },
-  "plugins": [
-    "@typescript-eslint"
-  ],
+  "plugins": ["@typescript-eslint"],
   "rules": {
-    "indent": ["error", 2],
+    "indent": ["error", 2, { "SwitchCase": 1 }],
     "linebreak-style": ["error", "unix"],
     "quotes": ["error", "double"],
-    "semi": ["error","always"],
+    "semi": ["error", "always"],
     "@typescript-eslint/no-explicit-any": "error",
-    "@typescript-eslint/explicit-function-return-type": ["error", {
-      "allowExpressions": true,
-      "allowTypedFunctionExpressions": true
-    }]
+    "@typescript-eslint/explicit-function-return-type": [
+      "error",
+      {
+        "allowExpressions": true,
+        "allowTypedFunctionExpressions": true
+      }
+    ]
   }
 }

.github/workflows/ci.yaml

@@ -23,7 +23,7 @@ jobs:
       - name: Lint & Unit Test
         run: |
           yarn lint
-          yarn test utils
+          yarn test unit
         # These are only relevant for e2e tests
         # env:
         #   NEAR_MULTICHAIN_CONTRACT: multichain-testnet-2.testnet

.prettierignore

@@ -0,0 +1 @@
+.eslintrc

src/chains/ethereum.ts

@@ -24,9 +24,9 @@ import {
 } from "../types/types";
 import { MultichainContract } from "../mpcContract";
 import BN from "bn.js";
-import { queryGasPrice } from "../utils/gasPrice";
-import { buildTxPayload, addSignature } from "../utils/transaction";
+import { buildTxPayload, addSignature, populateTx } from "../utils/transaction";
 import { Network } from "../network";
+import { pickValidSignature } from "../utils/signature";
 
 export class NearEthAdapter {
   readonly mpcContract: MultichainContract;
@@ -150,32 +150,9 @@ export class NearEthAdapter {
    * @returns {Hex} serialized (aka RLP encoded) transaction.
    */
   async buildTransaction(tx: BaseTx): Promise<Hex> {
-    const network = Network.fromChainId(tx.chainId);
-    const transactionData = {
-      nonce:
-        tx.nonce ||
-        (await network.client.getTransactionCount({
-          address: this.address,
-        })),
-      account: this.address,
-      to: tx.to,
-      value: tx.value ?? 0n,
-      data: tx.data ?? "0x",
-    };
-    const [estimatedGas, { maxFeePerGas, maxPriorityFeePerGas }] =
-      await Promise.all([
-        network.client.estimateGas(transactionData),
-        queryGasPrice(network.gasStationUrl),
-      ]);
-    const transactionDataWithGasLimit = {
-      ...transactionData,
-      gas: BigInt(estimatedGas.toString()),
-      maxFeePerGas,
-      maxPriorityFeePerGas,
-      chainId: network.chainId,
-    };
-    console.log("Transaction Request", transactionDataWithGasLimit);
-    return serializeTransaction(transactionDataWithGasLimit);
+    const transaction = await populateTx(tx, this.address);
+    console.log("Transaction Request", transaction);
+    return serializeTransaction(transaction);
   }
 
   reconstructSignature(tx: TransactionWithSignature): Hex {
@@ -225,7 +202,7 @@ export class NearEthAdapter {
         ...common,
       }),
     ]);
-    return this.pickValidSignature(validity, sigs);
+    return pickValidSignature(validity, sigs);
   }
 
   async signMessage(message: SignableMessage): Promise<Hash> {
@@ -244,7 +221,7 @@ export class NearEthAdapter {
         ...common,
       }),
     ]);
-    return this.pickValidSignature(validity, sigs);
+    return pickValidSignature(validity, sigs);
   }
 
   /**
@@ -268,17 +245,4 @@ export class NearEthAdapter {
       signatureToHex({ r, s, yParity: 1 }),
     ];
   }
-
-  private pickValidSignature(
-    [valid0, valid1]: [boolean, boolean],
-    [sig0, sig1]: [Hash, Hash]
-  ): Hash {
-    if (!valid0 && !valid1) {
-      throw new Error("Invalid signature");
-    } else if (valid0) {
-      return sig0;
-    } else {
-      return sig1;
-    }
-  }
 }

src/index.ts

@@ -1,5 +1,6 @@
 export * from "./chains/ethereum";
-export * from "./mpcContract";
 export * from "./chains/near";
+export * from "./mpcContract";
 export * from "./types/types";
+export * from "./utils/signature";
 export * from "./network";

src/mpcContract.ts

@@ -70,10 +70,10 @@ export class MultichainContract {
     return { big_r, big_s };
   };
 
-  encodeSignatureRequestTx = async (
+  encodeSignatureRequestTx(
     signArgs: SignArgs,
     gas?: BN
-  ): Promise<NearContractFunctionPayload> => {
+  ): NearContractFunctionPayload {
     return {
       signerId: this.contract.account.accountId,
       receiverId: this.contract.contractId,
@@ -89,5 +89,5 @@ export class MultichainContract {
         },
       ],
     };
-  };
+  }
 }

src/types/types.ts

@@ -14,6 +14,8 @@ export interface BaseTx {
   chainId: number;
   /// Specified transaction nonce
   nonce?: number;
+  /// optional gasLimit
+  gas?: bigint;
 }
 
 export interface NearEthAdapterParams {
@@ -52,7 +54,7 @@ export interface SignArgs {
 }
 
 export interface TxPayload {
-  /// Deserialized Ethereum Transaction.
+  /// Serialized Ethereum Transaction.
   transaction: Hex;
   /// Arguments required by Near MPC Contract signature request.
   signArgs: SignArgs;

src/utils/getSignature.ts → src/utils/signature.ts

@@ -1,3 +1,4 @@
+import { Hash } from "viem";
 import { JSONRPCResponse } from "../types/rpc";
 
 export async function signatureFromTxHash(
@@ -35,3 +36,16 @@ export async function signatureFromTxHash(
     throw new Error("No valid values found in the array.");
   }
 }
+
+export function pickValidSignature(
+  [valid0, valid1]: [boolean, boolean],
+  [sig0, sig1]: [Hash, Hash]
+): Hash {
+  if (!valid0 && !valid1) {
+    throw new Error("Invalid signature");
+  } else if (valid0) {
+    return sig0;
+  } else {
+    return sig1;
+  }
+}

src/utils/transaction.ts

@@ -1,22 +1,60 @@
 import {
   Address,
   Hex,
-  hexToBytes,
+  TransactionSerializable,
   hexToNumber,
   keccak256,
   parseTransaction,
   serializeTransaction,
   signatureToHex,
+  toBytes,
 } from "viem";
-import { TransactionWithSignature } from "../types/types";
+import { BaseTx, TransactionWithSignature } from "../types/types";
 import { secp256k1 } from "@noble/curves/secp256k1";
-
 import { publicKeyToAddress } from "viem/utils";
+import { queryGasPrice } from "./gasPrice";
+import { Network } from "../network";
+
+export function toPayload(hexString: Hex): number[] {
+  if (hexString.slice(2).length !== 32 * 2) {
+    throw new Error(`Payload Hex must have 32 bytes: ${hexString}`);
+  }
+  return Array.from(toBytes(hexString).reverse());
+}
 
 export function buildTxPayload(unsignedTxHash: `0x${string}`): number[] {
-  // Compute the Transaction Message Hash.
-  const messageHash = keccak256(unsignedTxHash);
-  return Array.from(hexToBytes(messageHash).slice().reverse());
+  return toPayload(keccak256(unsignedTxHash));
+}
+
+export async function populateTx(
+  tx: BaseTx,
+  from: Hex
+): Promise<TransactionSerializable> {
+  const network = Network.fromChainId(tx.chainId);
+  const transactionData = {
+    nonce:
+      tx.nonce ||
+      (await network.client.getTransactionCount({
+        address: from,
+      })),
+    account: from,
+    to: tx.to,
+    value: tx.value ?? 0n,
+    data: tx.data ?? "0x",
+  };
+  const [estimatedGas, { maxFeePerGas, maxPriorityFeePerGas }] =
+    await Promise.all([
+      // Only estimate gas if not provided.
+      tx.gas || network.client.estimateGas(transactionData),
+      queryGasPrice(network.gasStationUrl),
+    ]);
+  return {
+    ...transactionData,
+    gas: estimatedGas,
+    maxFeePerGas,
+    maxPriorityFeePerGas,
+    chainId: network.chainId,
+  };
 }
 
 export function addSignature(

tests/utils.kdf.test.ts → tests/unit/utils.kdf.test.ts

@@ -2,7 +2,7 @@ import {
   najPublicKeyStrToUncompressedHexPoint,
   deriveChildPublicKey,
   uncompressedHexPointToEvmAddress,
-} from "../src/utils/kdf";
+} from "../../src/utils/kdf";
 
 const ROOT_PK =
   "ecp256k1:4HFcTSodRLVCGNVcGc4Mf2fwBBBxv9jxkGdiW2S2CA1y6UpVVRWKj6RX7d7TDt65k2Bj3w9FU4BGtt43ZvuhCnNt";

tests/utils.getSignature.test.ts → tests/unit/utils.signature.test.ts

@@ -1,4 +1,4 @@
-import { signatureFromTxHash } from "../src/utils/getSignature";
+import { signatureFromTxHash } from "../../src/utils/signature";
 
 describe("utility: get Signature", () => {
   const url: string = "https://archival-rpc.testnet.near.org";

tests/utils.transaction.test.ts → tests/unit/utils.transaction.test.ts

@@ -1,5 +1,5 @@
-import { TransactionWithSignature } from "../src";
-import { buildTxPayload, addSignature } from "../src/utils/transaction";
+import { TransactionWithSignature } from "../../src";
+import { buildTxPayload, addSignature } from "../../src/utils/transaction";
 
 describe("Transaction Builder Functions", () => {
   it("buildTxPayload", async () => {