From 01d122b1e0a0c28cb05de64e03e4ef028316d2f4 Mon Sep 17 00:00:00 2001
From: Sameer Kumar Subudhi <sameer.subudhi@lightcurve.io>
Date: Thu, 19 Oct 2023 20:55:12 +0200
Subject: [PATCH] :hammer: Refactor code

---
 .eslintrc.js                     |  4 ++-
 docs/migration.md                | 11 +++----
 src/constants.ts                 | 16 +++++++---
 src/events.ts                    |  4 +--
 src/index.ts                     | 51 +++++++++++++++-----------------
 src/utils/commands.ts            | 17 +++++++----
 src/utils/exception.ts           |  6 ++--
 src/utils/genesis_block.ts       |  8 ++---
 src/utils/node.ts                | 42 ++++++++++++++++++--------
 test/unit/utils/commands.spec.ts |  7 ++---
 10 files changed, 99 insertions(+), 67 deletions(-)

diff --git a/.eslintrc.js b/.eslintrc.js
index e8db1793..932e36af 100644
--- a/.eslintrc.js
+++ b/.eslintrc.js
@@ -16,8 +16,9 @@ module.exports = {
 	rules: {
 		'max-len': 'off', // Managed by prettier
 		'no-underscore-dangle': 'off', // Used for private variables and methods
-		'implicit-arrow-linebreak': 'off', // Prefered
+		'implicit-arrow-linebreak': 'off', // Preferred
 		'no-mixed-spaces-and-tabs': 'off', // Managed by prettier
+		'no-shadow': 'off',
 		'operator-linebreak': 'off',
 		'import/prefer-default-export': 'off',
 		'lines-between-class-members': 'off', // Off because typescript has members and methods
@@ -31,6 +32,7 @@ module.exports = {
 		'@typescript-eslint/no-unnecessary-boolean-literal-compare': ['error'],
 		'@typescript-eslint/no-unnecessary-qualifier': ['error'],
 		'@typescript-eslint/no-unnecessary-type-arguments': ['error'],
+		'@typescript-eslint/no-shadow': 'warn',
 		'@typescript-eslint/prefer-for-of': ['error'],
 		'@typescript-eslint/prefer-function-type': ['error'],
 		'@typescript-eslint/prefer-includes': ['error'],
diff --git a/docs/migration.md b/docs/migration.md
index 5d40f5e1..969c0bc9 100644
--- a/docs/migration.md
+++ b/docs/migration.md
@@ -1,11 +1,12 @@
 # Migration Guide
 
-This section explains how to migrate a Lisk Core v3.0.4 (or later) node to Lisk Core v4.x using the Lisk Migrator.
+This section explains how to migrate a Lisk Core v3.1.0 node to Lisk Core v4.0.0 using the Lisk Migrator.
 
-The Lisk Migrator CLI tool will generate a new genesis (snapshot) block for Lisk Core v4.x.
-The new genesis block is created based on a snapshot of the existing blockchain (running on Lisk Core v3.0.4+) at a pre-determined height.
+The Lisk Migrator CLI tool will generate a new genesis (snapshot) block for Lisk Core v4.0.0.
+The new genesis block is created based on a snapshot of the existing blockchain (running on Lisk Core v3.1.0) at a pre-determined height.
 
-Lisk Migrator automatically exports the node's Forging Status information to the file named `forgingStatus.json` under the output directory. In case, Lisk Migrator is unable to save to the disk, as a fallback, the Forging Status information is logged to the standard output.
+Lisk Migrator automatically exports the node's Forging Status information to the file named `forgingStatus.json` under the output directory.
+In case, the Lisk Migrator is unable to save to the disk, as a fallback, the Forging Status information is logged to the standard output.
 
 <!--
 
@@ -67,7 +68,7 @@ export PATH="$PATH:$HOME/lisk-migrator/bin"
 **Check the announced snapshot height**
 
 - For Mainnet: `TBD`
-- For Testnet: `TBD`
+- For Testnet: `20449414`
 
 ### Run Lisk Migrator
 
diff --git a/src/constants.ts b/src/constants.ts
index 3c6e8566..361ef322 100644
--- a/src/constants.ts
+++ b/src/constants.ts
@@ -94,8 +94,16 @@ export const LEGACY_DB_PATH = `${DEFAULT_LISK_CORE_PATH}/${DEFAULT_DATA_DIR}/leg
 export const DEFAULT_VERSION = '0.1.0';
 export const EVENT_NEW_BLOCK = 'app:block:new';
 
-/* eslint-disable-next-line no-shadow */
-export const enum ERROR_CODES {
-	GENESIS_BLOCK_CREATE = 0,
-	LISK_CORE_START = 1,
+export const FILE_NAME = {
+	COMMANDS_TO_EXEC: 'commandsToExecute.txt',
+	FORGING_STATUS: 'forgingStatus.json',
+};
+
+export const enum ERROR_CODE {
+	DEFAULT = 0,
+	INVALID_CONFIG = 1,
+	GENESIS_BLOCK_CREATE = 2,
+	LISK_CORE_START = 3,
+	BACKUP_LEGACY_DATA_DIR = 4,
+	COPY_LEGACY_DB = 5,
 }
diff --git a/src/events.ts b/src/events.ts
index 491b901c..39a400b1 100644
--- a/src/events.ts
+++ b/src/events.ts
@@ -17,7 +17,7 @@ import { Block } from '@liskhq/lisk-chain';
 import { address } from '@liskhq/lisk-cryptography';
 import { APIClient } from '@liskhq/lisk-api-client';
 import { write } from './utils/fs';
-import { EVENT_NEW_BLOCK } from './constants';
+import { EVENT_NEW_BLOCK, FILE_NAME } from './constants';
 import { ForgingStatus } from './types';
 
 const { getLisk32AddressFromAddress } = address;
@@ -41,7 +41,7 @@ export const captureForgingStatusAtSnapshotHeight = (
 
 			if (finalForgingStatuses.length) {
 				try {
-					const forgingStatusJsonFilepath = resolve(outputDir, 'forgingStatus.json');
+					const forgingStatusJsonFilepath = resolve(outputDir, FILE_NAME.FORGING_STATUS);
 					await write(forgingStatusJsonFilepath, JSON.stringify(finalForgingStatuses, null, '\t'));
 					_this.log(`\nFinished exporting forging status to ${forgingStatusJsonFilepath}.`);
 				} catch (error) {
diff --git a/src/index.ts b/src/index.ts
index cee341c3..451e280f 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -26,7 +26,8 @@ import {
 	SNAPSHOT_DIR,
 	MIN_SUPPORTED_LISK_CORE_VERSION,
 	DEFAULT_LISK_CORE_PATH,
-	ERROR_CODES,
+	ERROR_CODE,
+	FILE_NAME,
 } from './constants';
 import { getAPIClient } from './client';
 import {
@@ -56,8 +57,8 @@ import { ApplicationConfigV3, NetworkConfigLocal, NodeInfo } from './types';
 import { installLiskCore, startLiskCore, isLiskCoreV3Running } from './utils/node';
 import { resolveAbsolutePath, verifyOutputPath } from './utils/path';
 import { execAsync } from './utils/process';
-import { CustomError } from './utils/exception';
-import { getCommandsToExecPostMigration, writeCommandsToExecute } from './utils/commands';
+import { MigratorException } from './utils/exception';
+import { writeCommandsToExec } from './utils/commands';
 
 let configCoreV4: PartialApplicationConfig;
 class LiskMigrator extends Command {
@@ -239,7 +240,12 @@ class LiskMigrator extends Command {
 				const isValidConfig = await validateConfig(migratedConfigV4);
 				cli.action.stop();
 
-				if (!isValidConfig) throw new Error('Migrated user configuration is invalid.');
+				if (!isValidConfig) {
+					throw new MigratorException(
+						'Migrated user configuration is invalid.',
+						ERROR_CODE.INVALID_CONFIG,
+					);
+				}
 
 				cli.action.start(`Exporting user configuration to the path: ${outputDir}`);
 				await writeConfig(migratedConfigV4, outputDir);
@@ -310,16 +316,14 @@ class LiskMigrator extends Command {
 									"Lisk Core v3 still running. Please stop the node, type 'yes' to proceed and 'no' to exit. [yes/no]",
 								);
 								if (!isStopReconfirmed) {
-									throw new CustomError(
+									throw new Error(
 										`Cannot proceed with Lisk Core v4 auto-start. Please continue manually. In order to access legacy blockchain information posts-migration, please copy the contents of the ${snapshotDirPath} directory to 'data/legacy.db' under the Lisk Core v4 data directory (e.g: ${DEFAULT_LISK_CORE_PATH}/data/legacy.db/). Exiting!!!`,
-										ERROR_CODES.LISK_CORE_START,
 									);
 								} else if (numTriesLeft === 0 && isStopReconfirmed) {
 									const isCoreV3StillRunning = await isLiskCoreV3Running(liskCoreV3DataPath);
 									if (isCoreV3StillRunning) {
-										throw new CustomError(
+										throw new Error(
 											`Cannot auto-start Lisk Core v4 as Lisk Core v3 is still running. Please continue manually. In order to access legacy blockchain information posts-migration, please copy the contents of the ${snapshotDirPath} directory to 'data/legacy.db' under the Lisk Core v4 data directory (e.g: ${DEFAULT_LISK_CORE_PATH}/data/legacy.db/). Exiting!!!`,
-											ERROR_CODES.LISK_CORE_START,
 										);
 									}
 								}
@@ -345,17 +349,13 @@ class LiskMigrator extends Command {
 							);
 						}
 					} else {
-						throw new CustomError(
+						throw new Error(
 							`User did not confirm Lisk Core v3 node shutdown. Skipping the Lisk Core v4 auto-start process. Please continue manually. In order to access legacy blockchain information posts-migration, please copy the contents of the ${snapshotDirPath} directory to 'data/legacy.db' under the Lisk Core v4 data directory (e.g: ${DEFAULT_LISK_CORE_PATH}/data/legacy.db/). Exiting!!!`,
-							ERROR_CODES.LISK_CORE_START,
 						);
 					}
 				} catch (err) {
-					/* eslint-disable-next-line @typescript-eslint/restrict-template-expressions */
-					throw new CustomError(
-						`Failed to auto-start Lisk Core v4.\nError: ${(err as Error).message}`,
-						ERROR_CODES.LISK_CORE_START,
-					);
+					const errorMsg = `Failed to auto-start Lisk Core v4.\nError: ${(err as Error).message}`;
+					throw new MigratorException(errorMsg, ERROR_CODE.LISK_CORE_START);
 				}
 			} else {
 				this.log(
@@ -365,40 +365,37 @@ class LiskMigrator extends Command {
 			}
 		} catch (error) {
 			const commandsToExecute: string[] = [];
-			const code = Number(`${(error as { message: string; code: number }).code}`);
+			const code = Number(`${(error as MigratorException).code}`);
 
 			const liskCoreStartCommand = `lisk core start--network ${networkConstant.name}`;
 
-			if (code === ERROR_CODES.GENESIS_BLOCK_CREATE) {
+			if (code === ERROR_CODE.GENESIS_BLOCK_CREATE) {
 				const genesisBlockCreateCommand = getGenesisBlockCreateCommand();
 				commandsToExecute.push(genesisBlockCreateCommand);
 				commandsToExecute.push(liskCoreStartCommand);
 			}
 
-			if (code === ERROR_CODES.LISK_CORE_START) {
+			if (code === ERROR_CODE.LISK_CORE_START) {
 				commandsToExecute.push(liskCoreStartCommand);
 			}
 
 			this.log(
-				`Creating file with the list of commands to execute: ${outputDir}/commandsToExecute.txt`,
-			);
-			await writeCommandsToExecute(
-				[...commandsToExecute, ...(await getCommandsToExecPostMigration(outputDir))],
-				outputDir,
+				`Creating file with the list of commands to execute: ${outputDir}/${FILE_NAME.COMMANDS_TO_EXEC}`,
 			);
+			await writeCommandsToExec(outputDir, commandsToExecute);
 			this.log(
-				`Successfully created file with the list of commands to execute: ${outputDir}/commandsToExecute.txt`,
+				`Successfully created file with the list of commands to execute: ${outputDir}/${FILE_NAME.COMMANDS_TO_EXEC}`,
 			);
 			this.error(`${(error as Error).message}`);
 		}
 
 		this.log('Successfully finished migration. Exiting!!!');
 		this.log(
-			`Creating file with the list of commands to execute post migration: ${outputDir}/commandsToExecute.txt`,
+			`Creating file with the list of commands to execute post migration: ${outputDir}/${FILE_NAME.COMMANDS_TO_EXEC}`,
 		);
-		await writeCommandsToExecute(await getCommandsToExecPostMigration(outputDir), outputDir);
+		await writeCommandsToExec(outputDir);
 		this.log(
-			`Successfully created file with the list of commands to execute post migration: ${outputDir}/commandsToExecute.txt`,
+			`Successfully created file with the list of commands to execute post migration: ${outputDir}/${FILE_NAME.COMMANDS_TO_EXEC}`,
 		);
 
 		process.exit(0);
diff --git a/src/utils/commands.ts b/src/utils/commands.ts
index 66a719ba..8867c4c4 100644
--- a/src/utils/commands.ts
+++ b/src/utils/commands.ts
@@ -15,6 +15,7 @@
 import { resolve } from 'path';
 
 import { read, write, exists } from './fs';
+import { FILE_NAME } from '../constants';
 
 export const getCommandsToExecPostMigration = async (outputDir: string) => {
 	const commandsToExecute = [];
@@ -24,7 +25,7 @@ export const getCommandsToExecPostMigration = async (outputDir: string) => {
 	);
 	commandsToExecute.push('lisk-core keys:import --file-path config/keys.json');
 
-	const forgingStatusJsonFilepath = resolve(outputDir, 'forgingStatus.json');
+	const forgingStatusJsonFilepath = resolve(outputDir, FILE_NAME.FORGING_STATUS);
 	if (await exists(forgingStatusJsonFilepath)) {
 		const forgingStatusString = (await read(forgingStatusJsonFilepath)) as string;
 		const forgingStatusJson = JSON.parse(forgingStatusString);
@@ -53,8 +54,14 @@ export const getCommandsToExecPostMigration = async (outputDir: string) => {
 	return commandsToExecute;
 };
 
-export const writeCommandsToExecute = async (commandsToExecute: string[], outputDir: string) => {
-	const commandsToExecuteFilepath = resolve(outputDir, 'commandsToExecute.txt');
-	const inputCommands = commandsToExecute.join('\n\n');
-	await write(commandsToExecuteFilepath, inputCommands);
+export const writeCommandsToExec = async (outputDir: string, preCompletionCommands?: string[]) => {
+	const commandsToExecPreCompletion = preCompletionCommands ?? [];
+	const commandsToExecPostMigration = await getCommandsToExecPostMigration(outputDir);
+
+	const allCommandsToExec = [...commandsToExecPreCompletion, ...commandsToExecPostMigration].join(
+		'\n\n',
+	);
+
+	const commandsToExecuteFilepath = resolve(outputDir, FILE_NAME.COMMANDS_TO_EXEC);
+	await write(commandsToExecuteFilepath, allCommandsToExec);
 };
diff --git a/src/utils/exception.ts b/src/utils/exception.ts
index 959b40f2..aa593201 100644
--- a/src/utils/exception.ts
+++ b/src/utils/exception.ts
@@ -11,9 +11,11 @@
  *
  * Removal or modification of this copyright notice is prohibited.
  */
+import { ERROR_CODE } from '../constants';
+
+export class MigratorException extends Error {
+	public code: number = ERROR_CODE.DEFAULT;
 
-export class CustomError extends Error {
-	public code: number;
 	public constructor(message: string, code: number) {
 		super(message);
 		this.code = code;
diff --git a/src/utils/genesis_block.ts b/src/utils/genesis_block.ts
index c0c3d3a2..085d5fef 100644
--- a/src/utils/genesis_block.ts
+++ b/src/utils/genesis_block.ts
@@ -16,11 +16,11 @@ import * as fs from 'fs-extra';
 import path from 'path';
 import { Command } from '@oclif/command';
 import { Block as BlockVersion3 } from '@liskhq/lisk-chain';
-import { ERROR_CODES, SNAPSHOT_TIME_GAP } from '../constants';
+import { ERROR_CODE, SNAPSHOT_TIME_GAP } from '../constants';
 import { GenesisAssetEntry } from '../types';
 import { execAsync } from './process';
 import { copyFile, createTarball } from './fs';
-import { CustomError } from './exception';
+import { MigratorException } from './exception';
 
 /* eslint-disable func-names, @typescript-eslint/no-explicit-any */
 (BigInt.prototype as any).toJSON = function () {
@@ -72,9 +72,9 @@ export const createGenesisBlock = async (
 
 		await execAsync(genesisBlockCreateCommand);
 	} catch (error) {
-		throw new CustomError(
+		throw new MigratorException(
 			`Failed to create genesis block.\nError: ${(error as Error).message}`,
-			ERROR_CODES.GENESIS_BLOCK_CREATE,
+			ERROR_CODE.GENESIS_BLOCK_CREATE,
 		);
 	}
 };
diff --git a/src/utils/node.ts b/src/utils/node.ts
index e6ca6217..41b317f3 100644
--- a/src/utils/node.ts
+++ b/src/utils/node.ts
@@ -29,11 +29,11 @@ import { getAPIClient } from '../client';
 import {
 	DEFAULT_PORT_P2P,
 	DEFAULT_PORT_RPC,
-	ERROR_CODES,
+	ERROR_CODE,
 	LEGACY_DB_PATH,
 	SNAPSHOT_DIR,
 } from '../constants';
-import { CustomError } from './exception';
+import { MigratorException } from './exception';
 
 const INSTALL_LISK_CORE_COMMAND = 'npm i -g lisk-core@^4.0.0-rc.1';
 const INSTALL_PM2_COMMAND = 'npm i -g pm2';
@@ -62,8 +62,8 @@ export const isLiskCoreV3Running = async (liskCorePath: string): Promise<boolean
 	}
 };
 
-const backupDefaultDirectoryIfExists = async (_this: Command, liskCoreV3DataPath: string) => {
-	if (existsSync(liskCoreV3DataPath)) {
+const backupLegacyDataDir = async (_this: Command, liskCoreV3DataPath: string) => {
+	try {
 		if (!liskCoreV3DataPath.includes('.lisk/lisk-core')) {
 			fs.mkdirSync(`${homedir()}/.lisk`, { recursive: true });
 		}
@@ -71,16 +71,28 @@ const backupDefaultDirectoryIfExists = async (_this: Command, liskCoreV3DataPath
 		_this.log(`Backing Lisk Core v3 data directory at ${liskCoreV3DataPath}`);
 		renameSync(liskCoreV3DataPath, LISK_V3_BACKUP_DATA_DIR);
 		_this.log(`Backed Lisk Core v3 data directory to: ${LISK_V3_BACKUP_DATA_DIR}`);
+	} catch (err) {
+		throw new MigratorException(
+			`Unable to backup Lisk Core v3 data directory due to: ${(err as Error).message}`,
+			ERROR_CODE.BACKUP_LEGACY_DATA_DIR,
+		);
 	}
 };
 
 const copyLegacyDB = async (_this: Command) => {
-	_this.log(`Copying the v3.x snapshot to legacy.db at ${LEGACY_DB_PATH}`);
-	await copyDir(
-		path.resolve(LISK_V3_BACKUP_DATA_DIR, SNAPSHOT_DIR),
-		resolveAbsolutePath(LEGACY_DB_PATH),
-	);
-	_this.log(`Legacy database for Lisk Core v4 has been created at ${LEGACY_DB_PATH}`);
+	try {
+		_this.log(`Copying the v3.x snapshot to legacy.db at ${LEGACY_DB_PATH}`);
+		await copyDir(
+			path.resolve(LISK_V3_BACKUP_DATA_DIR, SNAPSHOT_DIR),
+			resolveAbsolutePath(LEGACY_DB_PATH),
+		);
+		_this.log(`Legacy database for Lisk Core v4 has been created at ${LEGACY_DB_PATH}`);
+	} catch (err) {
+		throw new MigratorException(
+			`Unable to copy ${path.basename(LEGACY_DB_PATH)} due to: ${(err as Error).message}`,
+			ERROR_CODE.COPY_LEGACY_DB,
+		);
+	}
 };
 
 export const getFinalConfigPath = async (outputDir: string, network: string) =>
@@ -193,7 +205,8 @@ export const startLiskCore = async (
 			throw new Error(`Port ${rpcPort} is not available to start the RPC server.`);
 		}
 
-		await backupDefaultDirectoryIfExists(_this, liskCoreV3DataPath);
+		// Backup Lisk Core v3 data directory and legacy snapshot into the Core v4 legacy.db
+		await backupLegacyDataDir(_this, liskCoreV3DataPath);
 		await copyLegacyDB(_this);
 
 		const configPath = await getFinalConfigPath(outputDir, network);
@@ -229,7 +242,10 @@ export const startLiskCore = async (
 
 		const PM2_COMMAND_START = `pm2 start ${pm2FilePath}`;
 		_this.log(await execAsync(PM2_COMMAND_START));
-	} catch (error) {
-		throw new CustomError(`${(error as Error).message}`, ERROR_CODES.LISK_CORE_START);
+	} catch (err) {
+		throw new MigratorException(
+			`${(err as Error).message}`,
+			err instanceof MigratorException ? err.code : ERROR_CODE.LISK_CORE_START,
+		);
 	}
 };
diff --git a/test/unit/utils/commands.spec.ts b/test/unit/utils/commands.spec.ts
index c089c9a4..fc1dc51c 100644
--- a/test/unit/utils/commands.spec.ts
+++ b/test/unit/utils/commands.spec.ts
@@ -18,17 +18,16 @@ import {
 	writeCommandsToExecute,
 } from '../../../src/utils/commands';
 import { exists } from '../../../src/utils/fs';
+import { FILE_NAME } from '../../../src/constants';
 
 const outputDir = join(__dirname, '../../..', 'test/unit/fixtures');
 
-afterAll(() => {
-	fs.removeSync(join(outputDir, 'commandsToExecute.txt'));
-});
+afterAll(() => fs.removeSync(join(outputDir, FILE_NAME.COMMANDS_TO_EXEC)));
 
 describe('Test getCommandsToExecPostMigration method', () => {
 	it('should create commandsToExecute text file', async () => {
 		const commandsToExecute = await getCommandsToExecPostMigration(outputDir);
 		await writeCommandsToExecute(commandsToExecute, outputDir);
-		expect(await exists(`${outputDir}/commandsToExecute.txt`)).toBe(true);
+		expect(await exists(`${outputDir}/${FILE_NAME.COMMANDS_TO_EXEC}`)).toBe(true);
 	});
 });