Emit event new block and delete block with accounts - Closes #4825

elements/lisk-chain/src/chain.ts

@@ -100,6 +100,8 @@ interface ChainConstructor {
 
 const DEFAULT_MIN_BLOCK_HEADER_CACHE = 303;
 const DEFAULT_MAX_BLOCK_HEADER_CACHE = 505;
+const EVENT_NEW_BLOCK = 'NEW_BLOCK';
+const EVENT_DELETE_BLOCK = 'DELETE_BLOCK';
 
 // tslint:disable-next-line no-magic-numbers
 const TRANSACTION_TYPES_VOTE = [3, 11];
@@ -198,7 +200,7 @@ const undoConfirmedStep = async (
 
 const debug = Debug('lisk:chain');
 
-export class Chain extends EventEmitter {
+export class Chain {
 	private _lastBlock: BlockInstance;
 	private readonly blocksVerify: BlocksVerify;
 	private readonly storage: Storage;
@@ -217,6 +219,7 @@ export class Chain extends EventEmitter {
 		readonly activeDelegates: number;
 		readonly blockSlotWindow: number;
 	};
+	private readonly events: EventEmitter;
 
 	public readonly blockReward: {
 		readonly [key: string]: (height: number) => number | bigint;
@@ -247,7 +250,7 @@ export class Chain extends EventEmitter {
 		minBlockHeaderCache = DEFAULT_MIN_BLOCK_HEADER_CACHE,
 		maxBlockHeaderCache = DEFAULT_MAX_BLOCK_HEADER_CACHE,
 	}: ChainConstructor) {
-		super();
+		this.events = new EventEmitter();
 
 		this.storage = storage;
 		this.dataAccess = new DataAccess({
@@ -481,6 +484,15 @@ export class Chain extends EventEmitter {
 			}
 			this.dataAccess.addBlockHeader(blockInstance);
 			this._lastBlock = blockInstance;
+
+			const accounts = stateStore.account
+				.getUpdated()
+				.map(anAccount => anAccount.toJSON());
+
+			this.events.emit(EVENT_NEW_BLOCK, {
+				block: this.serialize(blockInstance),
+				accounts,
+			});
 		});
 	}
 
@@ -531,6 +543,15 @@ export class Chain extends EventEmitter {
 			await stateStore.finalize(tx);
 			await this.dataAccess.removeBlockHeader(block.id);
 			this._lastBlock = secondLastBlock;
+
+			const accounts = stateStore.account
+				.getUpdated()
+				.map(anAccount => anAccount.toJSON());
+
+			this.events.emit(EVENT_DELETE_BLOCK, {
+				block: this.serialize(block),
+				accounts,
+			});
 		});
 	}
 

elements/lisk-chain/test/unit/chain.spec.ts

@@ -21,6 +21,7 @@ import { registeredTransactions } from '../utils/registered_transactions';
 import * as randomUtils from '../utils/random';
 import { Slots } from '../../src/slots';
 import { BlockJSON } from '../../src/types';
+import { Account } from '../../src/account';
 
 jest.mock('events');
 
@@ -346,6 +347,11 @@ describe('chain', () => {
 	describe('save', () => {
 		let stateStoreStub: StateStore;
 
+		const fakeAccounts = [
+			Account.getDefaultAccount('1234L'),
+			Account.getDefaultAccount('5678L'),
+		];
+
 		beforeEach(async () => {
 			stubs.tx.batch.mockImplementation((promises: any) =>
 				Promise.all(promises),
@@ -355,6 +361,9 @@ describe('chain', () => {
 			);
 			stateStoreStub = {
 				finalize: jest.fn(),
+				account: {
+					getUpdated: jest.fn().mockReturnValue(fakeAccounts),
+				},
 			} as any;
 		});
 
@@ -471,14 +480,39 @@ describe('chain', () => {
 				blockCreateError,
 			);
 		});
+
+		it('should emit block and accounts', async () => {
+			// Arrange
+			jest.spyOn((chainInstance as any).events, 'emit');
+			const block = newBlock();
+
+			// Act
+			await chainInstance.save(block, stateStoreStub);
+
+			// Assert
+			expect((chainInstance as any).events.emit).toHaveBeenCalledWith(
+				'NEW_BLOCK',
+				{
+					accounts: fakeAccounts.map(anAccount => anAccount.toJSON()),
+					block: chainInstance.serialize(block),
+				},
+			);
+		});
 	});
 
 	describe('remove', () => {
 		let stateStoreStub: StateStore;
+		const fakeAccounts = [
+			Account.getDefaultAccount('1234L'),
+			Account.getDefaultAccount('5678L'),
+		];
 
 		beforeEach(async () => {
 			stateStoreStub = {
 				finalize: jest.fn(),
+				account: {
+					getUpdated: jest.fn().mockReturnValue(fakeAccounts),
+				},
 			} as any;
 			stubs.tx.batch.mockImplementation((promises: any) =>
 				Promise.all(promises),
@@ -586,6 +620,24 @@ describe('chain', () => {
 				);
 			});
 		});
+
+		it('should emit block and accounts', async () => {
+			// Arrange
+			jest.spyOn((chainInstance as any).events, 'emit');
+			const block = newBlock();
+
+			// Act
+			await chainInstance.save(block, stateStoreStub);
+
+			// Assert
+			expect((chainInstance as any).events.emit).toHaveBeenCalledWith(
+				'NEW_BLOCK',
+				{
+					accounts: fakeAccounts.map(anAccount => anAccount.toJSON()),
+					block: chainInstance.serialize(block),
+				},
+			);
+		});
 	});
 
 	describe('removeBlockFromTempTable()', () => {

framework/src/application/node/node.js

@@ -573,7 +573,5 @@ module.exports = class Node {
 
 	_unsubscribeToEvents() {
 		this.bft.removeAllListeners(EVENT_BFT_BLOCK_FINALIZED);
-		this.chain.removeAllListeners(EVENT_UNCONFIRMED_TRANSACTION);
-		this.chain.removeAllListeners(EVENT_MULTISIGNATURE_SIGNATURE);
 	}
 };