Introduce interoperability_getMainchainID endpoint

framework/src/modules/interoperability/schemas.ts

@@ -611,6 +611,22 @@ export const isChainNameAvailableResponseSchema = {
 	$id: '/modules/interoperability/endpoint/isChainNameAvailableResponseSchema',
 };
 
+export const getMainchainIDRequestSchema = {
+	...isChainIDAvailableRequestSchema,
+	$id: '/modules/interoperability/endpoint/getMainchainIDRequestSchema',
+};
+
+export const getMainchainIDResponseSchema = {
+	$id: '/modules/interoperability/endpoint/getMainchainIDResponseSchema',
+	type: 'object',
+	required: ['mainchainID'],
+	properties: {
+		result: {
+			type: 'string',
+		},
+	},
+};
+
 export const getChannelRequestSchema = getChainAccountRequestSchema;
 
 export const getTerminatedStateAccountRequestSchema = getChainAccountRequestSchema;

framework/src/modules/interoperability/sidechain/endpoint.ts

@@ -11,7 +11,17 @@
  *
  * Removal or modification of this copyright notice is prohibited.
  */
-
+import { validator } from '@liskhq/lisk-validator';
 import { BaseInteroperabilityEndpoint } from '../base_interoperability_endpoint';
+import { ModuleEndpointContext } from '../../../types';
+import { isChainIDAvailableRequestSchema } from '../schemas';
+import { getMainchainID } from '../utils';
+
+export class SidechainInteroperabilityEndpoint extends BaseInteroperabilityEndpoint {
+	public getMainchainID(context: ModuleEndpointContext): { mainchainID: string } {
+		validator.validate(isChainIDAvailableRequestSchema, context.params);
 
-export class SidechainInteroperabilityEndpoint extends BaseInteroperabilityEndpoint {}
+		const chainID = Buffer.from(context.params.chainID as string, 'hex');
+		return { mainchainID: getMainchainID(chainID).toString('hex') };
+	}
+}

framework/src/modules/interoperability/sidechain/module.ts

@@ -27,6 +27,8 @@ import {
 	getChannelRequestSchema,
 	getTerminatedOutboxAccountRequestSchema,
 	getTerminatedStateAccountRequestSchema,
+	getMainchainIDRequestSchema,
+	getMainchainIDResponseSchema,
 } from '../schemas';
 import { allChainAccountsSchema, chainDataSchema, ChainStatus } from '../stores/chain_account';
 import { channelSchema } from '../stores/channel_data';
@@ -194,6 +196,11 @@ export class SidechainInteroperabilityModule extends BaseInteroperabilityModule
 					request: getChainValidatorsRequestSchema,
 					response: getChainValidatorsResponseSchema,
 				},
+				{
+					name: this.endpoint.getMainchainID.name,
+					request: getMainchainIDRequestSchema,
+					response: getMainchainIDResponseSchema,
+				},
 			],
 			assets: [
 				{

framework/test/unit/modules/interoperability/sidechain/endpoint.spec.ts

@@ -0,0 +1,79 @@
+/*
+ * Copyright © 2023 Lisk Foundation
+ *
+ * See the LICENSE file at the top-level directory of this distribution
+ * for licensing information.
+ *
+ * Unless otherwise agreed in a custom licensing agreement with the Lisk Foundation,
+ * no part of this software, including this file, may be copied, modified,
+ * propagated, or distributed except according to the terms contained in the
+ * LICENSE file.
+ *
+ * Removal or modification of this copyright notice is prohibited.
+ */
+
+import { createTransientModuleEndpointContext } from '../../../../../src/testing';
+import { SidechainInteroperabilityEndpoint } from '../../../../../src/modules/interoperability/sidechain/endpoint';
+import { ModuleEndpointContext } from '../../../../../src';
+
+describe('SidechainInteroperabilityEndpoint', () => {
+	let endpoint: SidechainInteroperabilityEndpoint;
+
+	const storesMock = {};
+	const offchainStoresMock = {};
+
+	beforeEach(() => {
+		endpoint = new SidechainInteroperabilityEndpoint(storesMock as any, offchainStoresMock as any);
+	});
+
+	describe('getMainchainID', () => {
+		let context: ModuleEndpointContext;
+
+		it('should throw error for chainID having less than 8 chars', () => {
+			context = createTransientModuleEndpointContext({
+				params: {
+					chainID: '1234',
+				},
+			});
+
+			// https://stackoverflow.com/questions/47397208/error-is-thrown-but-jests-tothrow-does-not-capture-the-error
+			expect(() => endpoint.getMainchainID(context)).toThrow(
+				"Property '.chainID' must NOT have fewer than 8 characters",
+			);
+		});
+
+		it('should throw error for chainID having more than 8 chars', () => {
+			context = createTransientModuleEndpointContext({
+				params: {
+					chainID: '123456789',
+				},
+			});
+
+			expect(() => endpoint.getMainchainID(context)).toThrow(
+				"Property '.chainID' must NOT have more than 8 characters",
+			);
+		});
+
+		it('should return 00000000 for chainID 00123456', () => {
+			context = createTransientModuleEndpointContext({
+				params: {
+					chainID: '00123456',
+				},
+			});
+
+			const { mainchainID } = endpoint.getMainchainID(context);
+			expect(mainchainID).toBe('00000000');
+		});
+
+		it('should return 02000000 for chainID 02345678', () => {
+			context = createTransientModuleEndpointContext({
+				params: {
+					chainID: '02345678',
+				},
+			});
+
+			const { mainchainID } = endpoint.getMainchainID(context);
+			expect(mainchainID).toBe('02000000');
+		});
+	});
+});