add getSignature with test

src/types/rpc.ts

@@ -0,0 +1,131 @@
+// Basic structure of the JSON-RPC response
+export interface JSONRPCResponse {
+  jsonrpc: string;
+  result: Result;
+  id: string;
+}
+
+// Result contains various fields like final execution status, an array of receipts, etc.
+export interface Result {
+  final_execution_status: string;
+  receipts: Receipt[];
+  receipts_outcome: ReceiptOutcome[];
+  status: TransactionStatus;
+  transaction: Transaction;
+  transaction_outcome: TransactionOutcome;
+}
+
+// Define Receipt type with its structure
+interface Receipt {
+  predecessor_id: string;
+  receipt: ReceiptDetail;
+  receipt_id: string;
+  receiver_id: string;
+}
+
+// Detailed structure of a receipt which includes actions and other properties
+interface ReceiptDetail {
+  Action: ActionDetail;
+}
+
+// Actions within the receipt
+interface ActionDetail {
+  actions: Action[];
+  gas_price: string;
+  input_data_ids: any[];
+  output_data_receivers: any[];
+  signer_id: string;
+  signer_public_key: string;
+}
+
+// Action can have different types like FunctionCall or Transfer
+interface Action {
+  FunctionCall?: FunctionCall;
+  Transfer?: Transfer;
+}
+
+// FunctionCall action specifics
+interface FunctionCall {
+  args: string;
+  deposit: string;
+  gas: number;
+  method_name: string;
+}
+
+// Transfer action specifics
+interface Transfer {
+  deposit: string;
+}
+
+// Receipt outcomes are listed in an array
+export interface ReceiptOutcome {
+  block_hash: string;
+  id: string;
+  outcome: Outcome;
+  proof: Proof[];
+}
+
+// Outcome of executing the action
+interface Outcome {
+  executor_id: string;
+  gas_burnt: number;
+  logs: string[];
+  metadata: Metadata;
+  receipt_ids: string[];
+  status: OutcomeStatus;
+  tokens_burnt: string;
+}
+
+// Metadata may contain various gas profiling information
+interface Metadata {
+  gas_profile: GasProfile[];
+  version: number;
+}
+
+// Detailed gas usage per action or computation step
+interface GasProfile {
+  cost: string;
+  cost_category: string;
+  gas_used: number;
+}
+
+// Status of the outcome, success or failure specifics
+interface OutcomeStatus {
+  SuccessReceiptId?: string;
+  SuccessValue?: string;
+}
+
+// Proofs for the transaction validation
+interface Proof {
+  direction: string;
+  hash: string;
+}
+
+// Status field detailing the transaction execution result
+interface TransactionStatus {
+  SuccessValue: string;
+}
+
+// Transaction detail structure
+interface Transaction {
+  actions: TransactionAction[];
+  hash: string;
+  nonce: number;
+  public_key: string;
+  receiver_id: string;
+  signature: string;
+  signer_id: string;
+}
+
+// Actions within a transaction
+interface TransactionAction {
+  FunctionCall: FunctionCall;
+}
+
+// Transaction outcome mirrors structure similar to receipt outcomes
+interface TransactionOutcome {
+  block_hash: string;
+  id: string;
+  outcome: Outcome;
+  proof: Proof[];
+}

src/types/types.ts

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+import { MultichainContract } from "../mpcContract";
+import { FunctionCallAction } from "@near-wallet-selector/core";
+import BN from "bn.js";
+import { Hex } from "viem";
+
+export interface BaseTx {
+  /// Recipient of the transaction
+  to: `0x${string}`;
+  /// ETH value of transaction
+  value?: bigint;
+  /// Call Data of the transaction
+  data?: `0x${string}`;
+  /// integer ID of the network for the transaction.
+  chainId: number;
+  /// Specified transaction nonce
+  nonce?: number;
+}
+
+export interface NearEthAdapterParams {
+  /// An instance of the NearMPC contract connected to the associated near account.
+  mpcContract: MultichainContract;
+  /// path used to generate ETH account from Near account (e.g. "ethereum,1")
+  derivationPath?: string;
+}
+
+export interface GasPrices {
+  maxFeePerGas: bigint;
+  maxPriorityFeePerGas: bigint;
+}
+
+/// Near Contract Type for change methods
+export interface ChangeMethodArgs<T> {
+  /// Change method function agruments.
+  args: T;
+  /// GasLimit on transaction execution.
+  gas: BN;
+  /// Deposit (i.e. payable amount) to attach to transaction.
+  attachedDeposit: BN;
+}
+
+/**
+ * Arguments required for signature request from MPC Contract
+ * cf. https://github.com/near/mpc-recovery/blob/ac040bcbb31ba9362a6641a5899647105a53ee4a/contract/src/lib.rs#L297-L320
+ */
+export interface SignArgs {
+  /// Derivation Path of for ETH account associated with Near AccountId
+  path: string;
+  /// Serialized Ethereum Transaction Bytes.
+  payload: number[];
+  /// version number associated with derived ETH Address (must be increasing).
+  key_version: number;
+}
+
+export interface TxPayload {
+  /// Deserialized Ethereum Transaction.
+  transaction: Hex;
+  /// Arguments required by Near MPC Contract signature request.
+  signArgs: SignArgs;
+}
+
+export interface NearContractFunctionPayload {
+  /// Signer of function call.
+  signerId: string;
+  /// Transaction Recipient (a Near ContractId).
+  receiverId: string;
+  /// Function call actions.
+  actions: Array<FunctionCallAction>;
+}
+
+/**
+ * Result Type of MPC contract signature request.
+ * Representing Affine Points on eliptic curve.
+ */
+export interface MPCSignature {
+  big_r: string;
+  big_s: string;
+}
+
+/**
+ * Sufficient data required to construct a signed Ethereum Transaction.
+ */
+export interface TransactionWithSignature {
+  /// Unsigned Ethereum transaction data.
+  transaction: Hex;
+  /// Representation of the transaction's signature.
+  signature: MPCSignature;
+}

src/utils/getSignature.ts

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+import { JSONRPCResponse, ReceiptOutcome } from "../types/rpc";
+
+export async function signatureFromTxHash(
+  txHash: string,
+  accountId: string
+): Promise<[string, string]> {
+  const url: string = "https://archival-rpc.testnet.near.org";
+  const payload = {
+    jsonrpc: "2.0",
+    id: "dontcare",
+    method: "EXPERIMENTAL_tx_status",
+    params: [txHash, accountId],
+  };
+
+  // Make the POST request with the fetch API
+  const response = await fetch(url, {
+    method: "POST",
+    headers: {
+      "Content-Type": "application/json",
+    },
+    body: JSON.stringify(payload),
+  });
+
+  const jsonResponse = (await response.json()) as JSONRPCResponse;
+
+  const receiptsOutcome = jsonResponse.result.receipts_outcome;
+  const successValues = receiptsOutcome.map(
+    (outcome: ReceiptOutcome) => outcome.outcome.status.SuccessValue
+  );
+
+  // Find the first non-undefined value
+  const firstValidValue = successValues.find((value) => value !== undefined);
+
+  if (firstValidValue) {
+    // Decode from base64
+    const decodedValue = Buffer.from(firstValidValue, "base64").toString(
+      "utf-8"
+    );
+    return JSON.parse(decodedValue);
+  } else {
+    throw new Error("No valid values found in the array.");
+  }
+}

tests/utils.getSignature.test.ts

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+import { signatureFromTxHash } from "../src/utils/getSignature";
+
+describe("utility: get Signature", () => {
+  it("signatureFromTxHash", async () => {
+    const hash = "88LS5pkj99pd6B6noZU6sagQ1QDwHHoSy3qpHr5xLNsR";
+    const sig = await signatureFromTxHash(hash, "neareth-dev.testnet");
+    console.log(sig);
+  });
+});