Add unit tests for browser history functionality

BrowserHistory/tests/test_browser_history.py

@@ -0,0 +1,91 @@
+import unittest
+import sys
+import os
+
+# Add parent directory to path to import backend
+sys.path.append(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+from backend import BrowserHistory
+
+class TestBrowserHistory(unittest.TestCase):
+    def setUp(self):
+        """Set up test cases"""
+        self.browser = BrowserHistory("homepage.com")
+
+    def test_initialization(self):
+        """Test proper initialization of BrowserHistory"""
+        self.assertEqual(self.browser._curr.val, "homepage.com")
+        self.assertEqual(self.browser._back_count, 0)
+        self.assertEqual(self.browser._forward_count, 0)
+        self.assertIsNone(self.browser._curr.nxt)
+        self.assertIsNone(self.browser._curr.prev)
+
+    def test_visit(self):
+        """Test visit functionality and forward history cleanup"""
+        self.browser.visit("page1.com")
+        self.assertEqual(self.browser._curr.val, "page1.com")
+        self.assertEqual(self.browser._back_count, 1)
+        self.assertEqual(self.browser._forward_count, 0)
+
+        # Test forward history cleanup
+        self.browser.visit("page2.com")
+        self.browser.back(1)
+        self.browser.visit("page3.com")  # Should clear forward history
+        self.assertIsNone(self.browser._curr.nxt)
+        self.assertEqual(self.browser._forward_count, 0)
+
+    def test_back_navigation(self):
+        """Test back navigation with counter validation"""
+        # Setup history
+        self.browser.visit("page1.com")
+        self.browser.visit("page2.com")
+
+        # Test normal back navigation
+        result = self.browser.back(1)
+        self.assertEqual(result, "page1.com")
+        self.assertEqual(self.browser._back_count, 1)
+        self.assertEqual(self.browser._forward_count, 1)
+
+        # Test back with more steps than available
+        result = self.browser.back(5)  # Should only go back 1 step
+        self.assertEqual(result, "homepage.com")
+        self.assertEqual(self.browser._back_count, 0)
+        self.assertEqual(self.browser._forward_count, 2)
+
+    def test_forward_navigation(self):
+        """Test forward navigation with counter validation"""
+        # Setup history and position
+        self.browser.visit("page1.com")
+        self.browser.visit("page2.com")
+        self.browser.back(2)  # Go back to homepage
+
+        # Test normal forward navigation
+        result = self.browser.forward(1)
+        self.assertEqual(result, "page1.com")
+        self.assertEqual(self.browser._forward_count, 1)
+        self.assertEqual(self.browser._back_count, 1)
+
+        # Test forward with more steps than available
+        result = self.browser.forward(5)  # Should only go forward remaining 1 step
+        self.assertEqual(result, "page2.com")
+        self.assertEqual(self.browser._forward_count, 0)
+        self.assertEqual(self.browser._back_count, 2)
+
+    def test_complex_navigation(self):
+        """Test complex navigation patterns"""
+        self.browser.visit("page1.com")
+        self.browser.visit("page2.com")
+        self.browser.visit("page3.com")
+
+        # Back navigation
+        self.assertEqual(self.browser.back(2), "page1.com")
+
+        # New visit should clear forward history
+        self.browser.visit("page4.com")
+        self.assertEqual(self.browser._forward_count, 0)
+        self.assertIsNone(self.browser._curr.nxt)
+
+        # Verify we can't go forward to cleared history
+        self.assertEqual(self.browser.forward(1), "page4.com")
+
+if __name__ == '__main__':
+    unittest.main()