deck: completed function to create and shuffle a UNO card deck.

1. Added black to CardColor in types.d.ts.
2. Split special and wild cards into specialValues and wildCardValues arrays.
3. For each color in the colors array:
 - Add two cards for each number (0-9), except one card for '0'.
 - Add two cards for each special value.
 - For 'black', add four cards for each wild card value.
4. Added test,in deck.test.ts, to check the correct functioning of getShuffledCardDeck()
Fixes: #1

backend/src/types.d.ts

@@ -3,12 +3,12 @@
 
 type CardType = 'number' | 'special' | 'wild';
 
-type CardColor = 'red' | 'blue' | 'green' | 'yellow';
+type CardColor = 'red' | 'blue' | 'green' | 'yellow' | 'wild';
 
-type SpecialCardNames = 'skip' | 'reverse' | 'draw2' | 'draw4' | 'colchange';
-type CardNumbers = '0' | '1' | '2' | '3' | '4' | '5' | '6' | '7' | '8' | '9';
+type SpecialCardName = 'skip' | 'reverse' | 'draw2' | 'draw4' | 'colchange';
+type CardNumber = '0' | '1' | '2' | '3' | '4' | '5' | '6' | '7' | '8' | '9';
 
-type CardValue = SpecialCardNames | CardNumbers;
+type CardValue = SpecialCardName | CardNumber;
 
 type UNOCard = {
     type: CardType;

backend/tests/deck.test.ts

@@ -1,10 +1,68 @@
-import { shuffle, makeCard } from '../uno-game-engine/deck';
+import {
+    shuffle,
+    makeCard,
+    getShuffledCardDeck,
+} from '../uno-game-engine/deck';
+
+describe('getShuffledCardDeck', () => {
+    test('should return an array of 108 cards', () => {
+        const deck = getShuffledCardDeck();
+        expect(deck.length).toBe(108);
+        {
+            // Check the number of cards of each type
+            const numberCards = deck.filter((card) => card.type === 'number');
+            expect(numberCards.length).toBe(76);
+
+            const specialCards = deck.filter((card) => card.type === 'special');
+            expect(specialCards.length).toBe(24);
+
+            const wildCards = deck.filter((card) => card.type === 'wild');
+            expect(wildCards.length).toBe(8);
+        }
+        {
+            // Check the number of cards of red color
+            const redCards = deck.filter((card) => card.color === 'red');
+            expect(redCards.length).toBe(25); // 25 * 4 = 100 color cards
+        }
+        {
+            // Check the number of cards of 0 and 1 values
+            const zeroValueCards = deck.filter((card) => card.value === '0');
+            expect(zeroValueCards.length).toBe(4);
+
+            const oneValueCards = deck.filter((card) => card.value === '1');
+            expect(oneValueCards.length).toBe(8);
+        }
+        {
+            // Check the number of cards of special type
+            const skipCards = deck.filter((card) => card.value === 'skip');
+            expect(skipCards.length).toBe(8);
+
+            const draw2Cards = deck.filter((card) => card.value === 'draw2');
+            expect(draw2Cards.length).toBe(8);
+
+            const reverseCards = deck.filter(
+                (card) => card.value === 'reverse'
+            );
+            expect(reverseCards.length).toBe(8);
+        }
+        {
+            // Check the number of cards of wild type
+            const wildCards = deck.filter((card) => card.value === 'colchange');
+            expect(wildCards.length).toBe(4);
+
+            const draw4Cards = deck.filter((card) => card.value === 'draw4');
+            expect(draw4Cards.length).toBe(4);
+        }
+    });
+});
+
 describe('testing deck.ts', () => {
     test('makeCard', () => {
         const card = makeCard('number', 'blue', '3');
         expect(card.color).toBe('blue');
     });
 });
+
 describe('shuffle function', () => {
     test('should change order of elements', () => {
         // Create a mock deck

backend/uno-game-engine/deck.ts

@@ -1,5 +1,5 @@
-const colors: Array<CardColor> = ['red', 'yellow', 'green', 'blue'];
-const values = [
+const colors: Array<CardColor> = ['red', 'yellow', 'green', 'blue', 'wild'];
+const numValues: Array<CardNumber> = [
     '0',
     '1',
     '2',
@@ -10,12 +10,9 @@ const values = [
     '7',
     '8',
     '9',
-    'skip',
-    'reverse',
-    'draw2',
 ];
-const specialCards = ['wild', 'draw4'];
-const deck = [];
+const specialValues: Array<SpecialCardName> = ['skip', 'reverse', 'draw2'];
+const wildCardValues: Array<SpecialCardName> = ['colchange', 'draw4'];
 const sameCardCount = []; // to keep track of same cards in assigning unique id to each card
 
 /**    
@@ -42,11 +39,28 @@ const sameCardCount = []; // to keep track of same cards in assigning unique id
  @returns {Array} deck - An array of 108 UNO cards.
  */
 export function getShuffledCardDeck(): Array<UNOCard> {
-    const deck = [];
-    // todo: Implement the card generation logic
-    // dummy code:
-    // deck.push(makeCard('special', 'wild', 'wild'))
-    // deck.push(makeCard('number', 'red', '0'))
+    const deck: Array<UNOCard> = [];
+
+    colors.forEach((color) => {
+        if (color === 'wild') {
+            wildCardValues.forEach((value) => {
+                for (let i = 0; i < 4; i++) {
+                    deck.push(makeCard('wild', color, value));
+                }
+            });
+        } else {
+            numValues.forEach((value) => {
+                deck.push(makeCard('number', color, value));
+                if (value !== '0') {
+                    deck.push(makeCard('number', color, value));
+                }
+            });
+            specialValues.forEach((value) => {
+                deck.push(makeCard('special', color, value));
+                deck.push(makeCard('special', color, value));
+            });
+        }
+    });
 
     shuffle(deck);
     return deck;