Shuffle cards to review

src/lib/array/shuffle-array.test.ts

@@ -0,0 +1,42 @@
+import {describe, it, expect} from 'vitest'
+import {shuffleArray} from './shuffle-array.ts'
+
+describe('shuffleArray function', () => {
+  it('should shuffle an array of numbers', () => {
+    const array = [1, 2, 3, 4, 5];
+    const shuffled = shuffleArray([...array]);
+    expect(shuffled).not.toEqual(array);
+  });
+
+  it('should shuffle by reference', () => {
+    const array = [1, 2, 3, 4, 5];
+    const initialArray = [...array]
+    shuffleArray(array);
+    expect(array).not.toEqual(initialArray);
+  });
+
+  it('should shuffle an array of strings', () => {
+    const array = ['a', 'b', 'c', 'd', 'e'];
+    const shuffled = shuffleArray([...array]);
+    expect(shuffled).not.toEqual(array);
+  });
+
+  it('should handle an empty array', () => {
+    const array: unknown[] = [];
+    const shuffled = shuffleArray(array);
+    expect(shuffled).toEqual([]);
+  });
+
+  it('should retain all elements', () => {
+    const array = [1, 2, 3, 4, 5];
+    const shuffled = shuffleArray([...array]);
+    expect(shuffled.sort()).toEqual(array.sort());
+  });
+
+  it('should provide a random order', () => {
+    const array = [1, 2, 3, 4, 5];
+    const firstShuffle = shuffleArray([...array]);
+    const secondShuffle = shuffleArray([...array]);
+    expect(firstShuffle).not.toEqual(secondShuffle);
+  });
+});

src/lib/array/shuffle-array.ts

@@ -0,0 +1,15 @@
+export const shuffleArray = <T>(array: T[]): T[] => {
+  let currentIndex = array.length,
+    randomIndex;
+
+  while (currentIndex !== 0) {
+    randomIndex = Math.floor(Math.random() * currentIndex);
+    currentIndex--;
+    [array[currentIndex], array[randomIndex]] = [
+      array[randomIndex],
+      array[currentIndex],
+    ];
+  }
+
+  return array;
+};

src/store/card-under-review-store.ts

@@ -21,6 +21,7 @@ export class CardUnderReviewStore {
   back: string;
   example: string | null = null;
   deckName?: string;
+  deckId?: number;
   deckSpeakLocale: string | null = null;
   deckSpeakField: string | null = null;
 
@@ -33,6 +34,7 @@ export class CardUnderReviewStore {
     this.back = card.back;
     this.example = card.example;
     this.deckName = deck.name;
+    this.deckId = deck.id;
     this.deckSpeakLocale = deck.speak_locale;
     this.deckSpeakField = deck.speak_field;
 

src/store/review-store.test.ts

@@ -65,6 +65,14 @@ vi.mock("./deck-list-store.ts", () => {
   };
 });
 
+vi.mock('../lib/array/shuffle-array.ts', () => {
+  return {
+    shuffleArray: (array: unknown[]) => {
+      return array;
+    },
+  };
+})
+
 const cardToSnapshot = (card: CardUnderReviewStore) => ({
   back: card.back,
   deckName: card.deckName,

src/store/review-store.ts

@@ -8,6 +8,7 @@ import {
   deckListStore,
   DeckWithCardsWithReviewType,
 } from "./deck-list-store.ts";
+import { shuffleArray } from "../lib/array/shuffle-array.ts";
 
 type ReviewResult = {
   forgotIds: number[];
@@ -37,10 +38,12 @@ export class ReviewStore {
     if (!deck.cardsToReview.length) {
       return;
     }
-    deck.cardsToReview.forEach((card) => {
-      this.cardsToReview.push(new CardUnderReviewStore(card, deck));
-    });
+    const cardsToReview = deck.cardsToReview.map(
+      (card) => new CardUnderReviewStore(card, deck),
+    );
+    shuffleArray(cardsToReview);
 
+    this.cardsToReview = cardsToReview;
     this.initialCardCount = this.cardsToReview.length;
     this.currentCardId = this.cardsToReview[0].id;
     if (this.cardsToReview.length > 1) {
@@ -59,11 +62,13 @@ export class ReviewStore {
     }
 
     myDecks.forEach((deck) => {
-      deck.cardsToReview
+      const cardsToRepeat = deck.cardsToReview
         .filter((card) => card.type === "repeat")
-        .forEach((card) => {
-          this.cardsToReview.push(new CardUnderReviewStore(card, deck));
-        });
+        .map((card) => new CardUnderReviewStore(card, deck));
+
+      shuffleArray(cardsToRepeat);
+
+      this.cardsToReview.push(...cardsToRepeat);
     });
 
     if (!this.cardsToReview.length) {