added test for FirstTimeAnswers

src/components/__tests__/FirstTimeAnswers.spec.ts

+import { setActivePinia, createPinia } from 'pinia'
+import { FirstTimeAnswersStore } from '../../stores/FirstTimeAnswers'
+import { describe, it, expect, beforeEach } from 'vitest'
+
+describe('FirstTimeAnswersStore', () => {
+    beforeEach(() => {
+        setActivePinia(createPinia())
+    })
+
+    it('Sets user answer at specific index', () => {
+        const answersStore = FirstTimeAnswersStore()
+
+        expect(answersStore.userResponses).toEqual([])
+        answersStore.setUserAnswer(0, 'First answer')
+        expect(answersStore.userResponses).toEqual(['First answer'])
+        answersStore.setUserAnswer(1, 'Second answer')
+        expect(answersStore.userResponses).toEqual(['First answer', 'Second answer'])
+    })
+})