Address review: tighten lastFourPAN fallback comment and pin behavior with tests

Clarify the third-party `cardName` fallback in `useYourSpendData` so the
space requirement and no-space fall-through behavior are explicit, and
add two cases to `lastFourNumbersFromCardName` to lock that behavior in.

Author: adamgrzybowski

src/pages/home/YourSpendSection/useYourSpendData.ts

@@ -221,9 +221,9 @@ function useYourSpendData(): UseYourSpendDataReturn {
                 const total = snapshot?.count ? snapshot.total : cached?.total;
                 const currency = snapshot?.count ? snapshot.currency : cached?.currency;
 
-                // Some third-party cards leave `lastFourPAN` empty and stash the digits in
-                // `cardName` (e.g. "CREDIT CARD...1234"). Ternary, not `??`, so empty
-                // strings fall through.
+                // Fallback for third-party cards with empty `lastFourPAN` and digits in `cardName`
+                // (e.g. "CREDIT CARD...1234"; no-space names fall through to ""). Ternary so
+                // empty-string `lastFourPAN` also falls through.
                 const lastFour = card.lastFourPAN ? card.lastFourPAN : lastFourNumbersFromCardName(card.cardName);
                 if (!lastFour) {
                     return acc;

tests/unit/CardUtilsTest.ts

@@ -1578,6 +1578,16 @@ describe('CardUtils', () => {
             const lastFour = lastFourNumbersFromCardName('Business Card Cash - Business');
             expect(lastFour).toBe('');
         });
+
+        it('Should return last 4 numbers for an ellipsis name with a space (e.g. "CREDIT CARD...1234")', () => {
+            const lastFour = lastFourNumbersFromCardName('CREDIT CARD...1234');
+            expect(lastFour).toBe('1234');
+        });
+
+        it('Should return empty string for an ellipsis name without a space (e.g. "CREDITCARD...1234")', () => {
+            const lastFour = lastFourNumbersFromCardName('CREDITCARD...1234');
+            expect(lastFour).toBe('');
+        });
     });
 
     describe('maskCardNumber', () => {