Add unit tests for Counter component

src/tests/Counter.test.js

@@ -1,22 +1,44 @@
-// import necessary react testing library helpers here
-// import the Counter component here
+// Import necessary react testing library helpers
+import { render, screen, fireEvent } from '@testing-library/react';
+// Import the Counter component
+import Counter from '../components/Counter';
 
 beforeEach(() => {
-  // Render the Counter component here
-})
+    // Render the Counter component before each test
+    render(<Counter />);
+});
 
 test('renders counter message', () => {
-  // Complete the unit test below based on the objective in the line above
+    // Verify that the Counter message is rendered
+    expect(screen.getByText(/Counter/i)).toBeInTheDocument();
 });
 
 test('should render initial count with value of 0', () => {
-  // Complete the unit test below based on the objective in the line above
+    // Verify that the initial count is 0
+    const countElement = screen.getByTestId('count');
+    expect(countElement.textContent).toBe('0');
 });
 
 test('clicking + increments the count', () => {
-  // Complete the unit test below based on the objective in the line above
+    // Simulate clicking the + button and check the incremented value
+    const incrementButton = screen.getByText('+');
+    const countElement = screen.getByTestId('count');
+
+    fireEvent.click(incrementButton);
+    expect(countElement.textContent).toBe('1');
+
+    fireEvent.click(incrementButton);
+    expect(countElement.textContent).toBe('2');
 });
 
 test('clicking - decrements the count', () => {
-  // Complete the unit test below based on the objective in the line above
+    // Simulate clicking the - button and check the decremented value
+    const decrementButton = screen.getByText('-');
+    const countElement = screen.getByTestId('count');
+
+    fireEvent.click(decrementButton);
+    expect(countElement.textContent).toBe('-1');
+
+    fireEvent.click(decrementButton);
+    expect(countElement.textContent).toBe('-2');
 });