diff --git a/2-copy-of-code/lesson-09/ecommerce-project/src/pages/checkout/PaymentSummary.jsx b/2-copy-of-code/lesson-09/ecommerce-project/src/pages/checkout/PaymentSummary.jsx
index 045d77d..83fe7d6 100755
--- a/2-copy-of-code/lesson-09/ecommerce-project/src/pages/checkout/PaymentSummary.jsx
+++ b/2-copy-of-code/lesson-09/ecommerce-project/src/pages/checkout/PaymentSummary.jsx
@@ -19,35 +19,50 @@ export function PaymentSummary({ paymentSummary, loadCart }) {
 
       {paymentSummary && (
         <>
-          <div className="payment-summary-row">
+          <div
+            className="payment-summary-row"
+            data-testid="payment-summary-product-cost"
+          >
             <div>Items ({paymentSummary.totalItems}):</div>
             <div className="payment-summary-money">
               {formatMoney(paymentSummary.productCostCents)}
             </div>
           </div>
 
-          <div className="payment-summary-row">
+          <div
+            className="payment-summary-row"
+            data-testid="payment-summary-shipping-cost"
+          >
             <div>Shipping &amp; handling:</div>
             <div className="payment-summary-money">
               {formatMoney(paymentSummary.shippingCostCents)}
             </div>
           </div>
 
-          <div className="payment-summary-row subtotal-row">
+          <div
+            className="payment-summary-row subtotal-row"
+            data-testid="payment-summary-total-before-tax"
+          >
             <div>Total before tax:</div>
             <div className="payment-summary-money">
               {formatMoney(paymentSummary.totalCostBeforeTaxCents)}
             </div>
           </div>
 
-          <div className="payment-summary-row">
+          <div
+            className="payment-summary-row"
+            data-testid="payment-summary-tax"
+          >
             <div>Estimated tax (10%):</div>
             <div className="payment-summary-money">
               {formatMoney(paymentSummary.taxCents)}
             </div>
           </div>
 
-          <div className="payment-summary-row total-row">
+          <div
+            className="payment-summary-row total-row"
+            data-testid="payment-summary-total"
+          >
             <div>Order total:</div>
             <div className="payment-summary-money">
               {formatMoney(paymentSummary.totalCostCents)}
diff --git a/2-copy-of-code/lesson-09/ecommerce-project/src/pages/checkout/PaymentSummary.test.jsx b/2-copy-of-code/lesson-09/ecommerce-project/src/pages/checkout/PaymentSummary.test.jsx
new file mode 100644
index 0000000..2539c9e
--- /dev/null
+++ b/2-copy-of-code/lesson-09/ecommerce-project/src/pages/checkout/PaymentSummary.test.jsx
@@ -0,0 +1,63 @@
+import { it, expect, describe, vi, beforeEach } from 'vitest';
+import { render, screen, within } from '@testing-library/react';
+import { MemoryRouter } from 'react-router';
+import { PaymentSummary } from './PaymentSummary';
+
+describe('PaymentSummary component', () => {
+  let paymentSummary;
+  let loadCart;
+
+  beforeEach(() => {
+    paymentSummary = {
+      totalItems: 3,
+      productCostCents: 4275,
+      shippingCostCents: 499,
+      totalCostBeforeTaxCents: 4774,
+      taxCents: 477,
+      totalCostCents: 5251
+    };
+
+    loadCart = vi.fn();
+  });
+
+  it('displays the correct details', async () => {
+    render(
+      <MemoryRouter>
+        <PaymentSummary
+          paymentSummary={paymentSummary}
+          loadCart={loadCart}
+        />
+      </MemoryRouter>
+    );
+
+    expect(
+      screen.getByText('Items (3):')
+    ).toBeInTheDocument();
+
+    // There are multiple ways to check the text inside an element.
+    // 1. within() + getByText() + toBeInTheDocument()
+    expect(
+      within(screen.getByTestId('payment-summary-product-cost'))
+        .getByText('$42.75')
+    ).toBeInTheDocument();
+
+    // 2. getByTestId() + toHaveTextContent()
+    // (toHaveTextContent() checks the text inside an element)
+    // This solution is a little cleaner in this case.
+    expect(
+      screen.getByTestId('payment-summary-shipping-cost')
+    ).toHaveTextContent('$4.99');
+
+    expect(
+      screen.getByTestId('payment-summary-total-before-tax')
+    ).toHaveTextContent('$47.74');
+
+    expect(
+      screen.getByTestId('payment-summary-tax')
+    ).toHaveTextContent('$4.77');
+
+    expect(
+      screen.getByTestId('payment-summary-total')
+    ).toHaveTextContent('$52.51');
+  });
+});
\ No newline at end of file