From fe97049d1a666ca5832cec67427883dabd43ae60 Mon Sep 17 00:00:00 2001
From: Chris Wilton-Magras <chriswilty@zoho.com>
Date: Thu, 25 Jan 2024 17:32:59 +0000
Subject: [PATCH] Prevent mutating state reset template (#798)

---
 backend/src/app.ts                            |  4 ++--
 backend/src/controller/resetController.ts     |  4 ++--
 backend/src/models/level.ts                   | 23 +++++++++++--------
 .../unit/controller/resetController.test.ts   | 12 ++++++----
 4 files changed, 26 insertions(+), 17 deletions(-)

diff --git a/backend/src/app.ts b/backend/src/app.ts
index 22bfea7a3..642eeef05 100644
--- a/backend/src/app.ts
+++ b/backend/src/app.ts
@@ -7,7 +7,7 @@ import { fileURLToPath } from 'node:url';
 
 import { importMetaUrl } from './importMetaUtils';
 import { ChatModel, defaultChatModel } from './models/chat';
-import { LevelState, levelsInitialState } from './models/level';
+import { LevelState, getInitialLevelStates } from './models/level';
 import { router } from './router';
 
 dotenv.config();
@@ -55,7 +55,7 @@ app.use((req, _res, next) => {
 	// initialise session variables first time
 	if (!req.session.initialised) {
 		req.session.chatModel = defaultChatModel;
-		req.session.levelState = levelsInitialState;
+		req.session.levelState = getInitialLevelStates();
 		req.session.initialised = true;
 	}
 	next();
diff --git a/backend/src/controller/resetController.ts b/backend/src/controller/resetController.ts
index 0e697e9e2..b6d974921 100644
--- a/backend/src/controller/resetController.ts
+++ b/backend/src/controller/resetController.ts
@@ -1,10 +1,10 @@
 import { Request, Response } from 'express';
 
-import { levelsInitialState } from '@src/models/level';
+import { getInitialLevelStates } from '@src/models/level';
 
 function handleResetProgress(req: Request, res: Response) {
 	console.debug('Resetting progress for all levels', req.session.levelState);
-	req.session.levelState = levelsInitialState;
+	req.session.levelState = getInitialLevelStates();
 	res.send(req.session.levelState);
 }
 
diff --git a/backend/src/models/level.ts b/backend/src/models/level.ts
index 0b862ac06..6659e4932 100644
--- a/backend/src/models/level.ts
+++ b/backend/src/models/level.ts
@@ -18,14 +18,19 @@ interface LevelState {
 	sentEmails: EmailInfo[];
 }
 
-const levelsInitialState = Object.values(LEVEL_NAMES)
-	.filter((value) => Number.isNaN(Number(value)))
-	.map((value) => ({
-		level: value as LEVEL_NAMES,
-		chatHistory: [],
-		defences: defaultDefences,
-		sentEmails: [],
-	}));
+function getInitialLevelStates() {
+	return Object.values(LEVEL_NAMES)
+		.filter((value) => Number.isNaN(Number(value)))
+		.map(
+			(value) =>
+				({
+					level: value as LEVEL_NAMES,
+					chatHistory: [],
+					defences: defaultDefences,
+					sentEmails: [],
+				} as LevelState)
+		);
+}
 
-export { LEVEL_NAMES, levelsInitialState };
+export { LEVEL_NAMES, getInitialLevelStates };
 export type { LevelState };
diff --git a/backend/test/unit/controller/resetController.test.ts b/backend/test/unit/controller/resetController.test.ts
index fd280fc5d..cb5a98f6c 100644
--- a/backend/test/unit/controller/resetController.test.ts
+++ b/backend/test/unit/controller/resetController.test.ts
@@ -10,7 +10,11 @@ import {
 } from '@src/models/chat';
 import { DEFENCE_ID, Defence, DefenceConfigItem } from '@src/models/defence';
 import { EmailInfo } from '@src/models/email';
-import { LEVEL_NAMES, LevelState, levelsInitialState } from '@src/models/level';
+import {
+	LEVEL_NAMES,
+	LevelState,
+	getInitialLevelStates,
+} from '@src/models/level';
 
 declare module 'express-session' {
 	interface Session {
@@ -69,7 +73,7 @@ describe('handleResetProgress unit tests', () => {
 
 		const res = responseMock();
 		handleResetProgress(reqWithChatHistory, res);
-		expect(res.send).toHaveBeenCalledWith(levelsInitialState);
+		expect(res.send).toHaveBeenCalledWith(getInitialLevelStates());
 	});
 
 	test('GIVEN sent emails THEN should reset emails for all levels', () => {
@@ -84,7 +88,7 @@ describe('handleResetProgress unit tests', () => {
 
 		const res = responseMock();
 		handleResetProgress(reqWithSentEmails, res);
-		expect(res.send).toHaveBeenCalledWith(levelsInitialState);
+		expect(res.send).toHaveBeenCalledWith(getInitialLevelStates());
 	});
 
 	test('GIVEN defences THEN should reset defences for levels', () => {
@@ -116,6 +120,6 @@ describe('handleResetProgress unit tests', () => {
 
 		const res = responseMock();
 		handleResetProgress(reqWithDefences, res);
-		expect(res.send).toHaveBeenCalledWith(levelsInitialState);
+		expect(res.send).toHaveBeenCalledWith(getInitialLevelStates());
 	});
 });