Docs: Add ecosystem examples to CoR, add Factory tests (#466)

Co-authored-by: Sakis Kasampalis <faif@users.noreply.github.com>

Author: SanjanaG-01

patterns/behavioral/chain_of_responsibility.py

@@ -14,6 +14,10 @@
 As a variation some receivers may be capable of sending requests out
 in several directions, forming a `tree of responsibility`.
 
+*Examples in Python ecosystem:
+Django Middleware: https://docs.djangoproject.com/en/stable/topics/http/middleware/
+The middleware components act as a chain where each processes the request/response.
+
 *TL;DR
 Allow a request to pass down a chain of receivers until it is handled.
 """

tests/creational/test_factory.py

@@ -0,0 +1,30 @@
+import unittest
+from patterns.creational.factory import get_localizer, GreekLocalizer, EnglishLocalizer
+
+class TestFactory(unittest.TestCase):
+    def test_get_localizer_greek(self):
+        localizer = get_localizer("Greek")
+        self.assertIsInstance(localizer, GreekLocalizer)
+        self.assertEqual(localizer.localize("dog"), "σκύλος")
+        self.assertEqual(localizer.localize("cat"), "γάτα")
+        # Test unknown word returns the word itself
+        self.assertEqual(localizer.localize("monkey"), "monkey")
+
+    def test_get_localizer_english(self):
+        localizer = get_localizer("English")
+        self.assertIsInstance(localizer, EnglishLocalizer)
+        self.assertEqual(localizer.localize("dog"), "dog")
+        self.assertEqual(localizer.localize("cat"), "cat")
+
+    def test_get_localizer_default(self):
+        # Test default argument
+        localizer = get_localizer()
+        self.assertIsInstance(localizer, EnglishLocalizer)
+
+    def test_get_localizer_unknown_language(self):
+        # Test fallback for unknown language if applicable, 
+        # or just verify what happens. 
+        # Based on implementation: localizers.get(language, EnglishLocalizer)()
+        # It defaults to EnglishLocalizer for unknown keys.
+        localizer = get_localizer("Spanish")
+        self.assertIsInstance(localizer, EnglishLocalizer)