icrc index getLedgerId (#693)

# Motivation

For the import token functionality, we need to ensure that the provided
by users index canister is correctly associated with the same token and
not mistakenly linked to a different ledger canister. To achieve this,
we going to use the `ledger_id` API of the index canister, which returns
the corresponding ledger canister ID. This PR introduces a function that
makes the `ledger_id` request.

# Changes

- Add getLedgerId function.

# Tests

- Test for getLedgerId.
- Tested manually in nns-dapp against localhost.

# Todos

- [ ] Add entry to changelog (if necessary).
Not necessary.

---------

Co-authored-by: github-actions <41898282+github-actions[bot]@users.noreply.github.com>

packages/ledger-icrc/README.md

@@ -275,20 +275,21 @@ Parameters:
 
 ### :factory: IcrcIndexCanister
 
-[:link: Source](https://github.com/dfinity/ic-js/tree/main/packages/ledger-icrc/src/index.canister.ts#L13)
+[:link: Source](https://github.com/dfinity/ic-js/tree/main/packages/ledger-icrc/src/index.canister.ts#L14)
 
 #### Methods
 
 - [create](#gear-create)
 - [getTransactions](#gear-gettransactions)
+- [ledgerId](#gear-ledgerid)
 
 ##### :gear: create
 
 | Method   | Type                                                                  |
 | -------- | --------------------------------------------------------------------- |
 | `create` | `(options: IcrcLedgerCanisterOptions<_SERVICE>) => IcrcIndexCanister` |
 
-[:link: Source](https://github.com/dfinity/ic-js/tree/main/packages/ledger-icrc/src/index.canister.ts#L14)
+[:link: Source](https://github.com/dfinity/ic-js/tree/main/packages/ledger-icrc/src/index.canister.ts#L15)
 
 ##### :gear: getTransactions
 
@@ -303,7 +304,17 @@ Index Canister only holds the transactions ids in state, not the whole transacti
 | ----------------- | -------------------------------------------------------------------- |
 | `getTransactions` | `(params: GetAccountTransactionsParams) => Promise<GetTransactions>` |
 
-[:link: Source](https://github.com/dfinity/ic-js/tree/main/packages/ledger-icrc/src/index.canister.ts#L33)
+[:link: Source](https://github.com/dfinity/ic-js/tree/main/packages/ledger-icrc/src/index.canister.ts#L34)
+
+##### :gear: ledgerId
+
+Returns the ledger canister ID related to the index canister.
+
+| Method     | Type                                          |
+| ---------- | --------------------------------------------- |
+| `ledgerId` | `(params: QueryParams) => Promise<Principal>` |
+
+[:link: Source](https://github.com/dfinity/ic-js/tree/main/packages/ledger-icrc/src/index.canister.ts#L51)
 
 ### :factory: IcrcIndexNgCanister
 

packages/ledger-icrc/src/index.canister.spec.ts

@@ -8,7 +8,7 @@ import type {
 } from "../candid/icrc_index";
 import { IndexError } from "./errors/index.errors";
 import { IcrcIndexCanister } from "./index.canister";
-import { indexCanisterIdMock } from "./mocks/ledger.mock";
+import { indexCanisterIdMock, ledgerCanisterIdMock } from "./mocks/ledger.mock";
 import { IcrcAccount } from "./types/ledger.responses";
 
 describe("Index canister", () => {
@@ -91,4 +91,22 @@ describe("Index canister", () => {
       expect(call).rejects.toThrowError(IndexError);
     });
   });
+
+  describe("ledgerId", () => {
+    it("should return ledger id", async () => {
+      const service = mock<ActorSubclass<IcrcIndexService>>();
+      service.ledger_id.mockResolvedValue(ledgerCanisterIdMock);
+
+      const canister = IcrcIndexCanister.create({
+        canisterId: indexCanisterIdMock,
+        certifiedServiceOverride: service,
+      });
+
+      const result = await canister.ledgerId({
+        certified: true,
+      });
+
+      expect(result).toEqual(ledgerCanisterIdMock);
+    });
+  });
 });

packages/ledger-icrc/src/index.canister.ts

@@ -1,4 +1,5 @@
-import { Canister, createServices } from "@dfinity/utils";
+import type { Principal } from "@dfinity/principal";
+import { Canister, createServices, type QueryParams } from "@dfinity/utils";
 import type {
   GetTransactions,
   _SERVICE as IcrcIndexService,
@@ -43,4 +44,12 @@ export class IcrcIndexCanister extends Canister<IcrcIndexService> {
 
     return response.Ok;
   };
+
+  /**
+   * Returns the ledger canister ID related to the index canister.
+   */
+  ledgerId = (params: QueryParams): Promise<Principal> => {
+    const { ledger_id } = this.caller(params);
+    return ledger_id();
+  };
 }