Translate several doctest tests to pytest

Author: Benjamin Townsend

.gitignore

@@ -10,3 +10,6 @@ venv/
 .vscode/
 .python-version
 .coverage
+.project
+.pydevproject
+/.pytest_cache/

patterns/behavioral/catalog.py

@@ -1,15 +1,13 @@
 """
-A class that uses different static function depending of a parameter passed in
-init. Note the use of a single dictionary instead of multiple conditions
+A class that uses a different static function depending on a parameter passed in
+init. Note the use of a single dictionary instead of multiple conditions.
 """
 
 __author__ = "Ibrahim Diop <[email protected]>"
 
 
 class Catalog:
-    """catalog of multiple static methods that are executed depending on an init
-
-    parameter
+    """catalog of multiple static methods that are executed depending on an init parameter
     """
 
     def __init__(self, param: str) -> None:
@@ -29,27 +27,24 @@ def __init__(self, param: str) -> None:
             raise ValueError(f"Invalid Value for Param: {param}")
 
     @staticmethod
-    def _static_method_1() -> None:
-        print("executed method 1!")
+    def _static_method_1() -> str:
+        return "executed method 1!"
 
     @staticmethod
-    def _static_method_2() -> None:
-        print("executed method 2!")
+    def _static_method_2() -> str:
+        return "executed method 2!"
 
-    def main_method(self) -> None:
+    def main_method(self) -> str:
         """will execute either _static_method_1 or _static_method_2
 
         depending on self.param value
         """
-        self._static_method_choices[self.param]()
+        return self._static_method_choices[self.param]()
 
 
 # Alternative implementation for different levels of methods
 class CatalogInstance:
-
-    """catalog of multiple methods that are executed depending on an init
-
-    parameter
+    """catalog of multiple methods that are executed depending on an init parameter
     """
 
     def __init__(self, param: str) -> None:
@@ -61,31 +56,28 @@ def __init__(self, param: str) -> None:
         else:
             raise ValueError(f"Invalid Value for Param: {param}")
 
-    def _instance_method_1(self) -> None:
-        print(f"Value {self.x1}")
+    def _instance_method_1(self) -> str:
+        return f"Value {self.x1}"
 
-    def _instance_method_2(self) -> None:
-        print(f"Value {self.x2}")
+    def _instance_method_2(self) -> str:
+        return f"Value {self.x2}"
 
     _instance_method_choices = {
         "param_value_1": _instance_method_1,
         "param_value_2": _instance_method_2,
     }
 
-    def main_method(self) -> None:
+    def main_method(self) -> str:
         """will execute either _instance_method_1 or _instance_method_2
 
         depending on self.param value
         """
-        self._instance_method_choices[self.param].__get__(self)()  # type: ignore
+        return self._instance_method_choices[self.param].__get__(self)()  # type: ignore
         # type ignore reason: https://github.com/python/mypy/issues/10206
 
 
 class CatalogClass:
-
-    """catalog of multiple class methods that are executed depending on an init
-
-    parameter
+    """catalog of multiple class methods that are executed depending on an init parameter
     """
 
     x1 = "x1"
@@ -99,32 +91,29 @@ def __init__(self, param: str) -> None:
             raise ValueError(f"Invalid Value for Param: {param}")
 
     @classmethod
-    def _class_method_1(cls) -> None:
-        print(f"Value {cls.x1}")
+    def _class_method_1(cls) -> str:
+        return f"Value {cls.x1}"
 
     @classmethod
-    def _class_method_2(cls) -> None:
-        print(f"Value {cls.x2}")
+    def _class_method_2(cls) -> str:
+        return f"Value {cls.x2}"
 
     _class_method_choices = {
         "param_value_1": _class_method_1,
         "param_value_2": _class_method_2,
     }
 
-    def main_method(self):
+    def main_method(self) -> str:
         """will execute either _class_method_1 or _class_method_2
 
         depending on self.param value
         """
-        self._class_method_choices[self.param].__get__(None, self.__class__)()  # type: ignore
+        return self._class_method_choices[self.param].__get__(None, self.__class__)()  # type: ignore
         # type ignore reason: https://github.com/python/mypy/issues/10206
 
 
 class CatalogStatic:
-
-    """catalog of multiple static methods that are executed depending on an init
-
-    parameter
+    """catalog of multiple static methods that are executed depending on an init parameter
     """
 
     def __init__(self, param: str) -> None:
@@ -135,45 +124,45 @@ def __init__(self, param: str) -> None:
             raise ValueError(f"Invalid Value for Param: {param}")
 
     @staticmethod
-    def _static_method_1() -> None:
-        print("executed method 1!")
+    def _static_method_1() -> str:
+        return "executed method 1!"
 
     @staticmethod
-    def _static_method_2() -> None:
-        print("executed method 2!")
+    def _static_method_2() -> str:
+        return "executed method 2!"
 
     _static_method_choices = {
         "param_value_1": _static_method_1,
         "param_value_2": _static_method_2,
     }
 
-    def main_method(self) -> None:
+    def main_method(self) -> str:
         """will execute either _static_method_1 or _static_method_2
 
         depending on self.param value
         """
 
-        self._static_method_choices[self.param].__get__(None, self.__class__)()  # type: ignore
+        return self._static_method_choices[self.param].__get__(None, self.__class__)()  # type: ignore
         # type ignore reason: https://github.com/python/mypy/issues/10206
 
 
 def main():
     """
     >>> test = Catalog('param_value_2')
     >>> test.main_method()
-    executed method 2!
+    'executed method 2!'
 
     >>> test = CatalogInstance('param_value_1')
     >>> test.main_method()
-    Value x1
+    'Value x1'
 
     >>> test = CatalogClass('param_value_2')
     >>> test.main_method()
-    Value x2
+    'Value x2'
 
     >>> test = CatalogStatic('param_value_1')
     >>> test.main_method()
-    executed method 1!
+    'executed method 1!'
     """
 
 

patterns/behavioral/mediator.py

@@ -15,7 +15,7 @@ class ChatRoom:
     """Mediator class"""
 
     def display_message(self, user: User, message: str) -> None:
-        print(f"[{user} says]: {message}")
+        return f"[{user} says]: {message}"
 
 
 class User:
@@ -26,7 +26,7 @@ def __init__(self, name: str) -> None:
         self.chat_room = ChatRoom()
 
     def say(self, message: str) -> None:
-        self.chat_room.display_message(self, message)
+        return self.chat_room.display_message(self, message)
 
     def __str__(self) -> str:
         return self.name
@@ -39,11 +39,11 @@ def main():
     >>> ethan = User('Ethan')
 
     >>> molly.say("Hi Team! Meeting at 3 PM today.")
-    [Molly says]: Hi Team! Meeting at 3 PM today.
+    '[Molly says]: Hi Team! Meeting at 3 PM today.'
     >>> mark.say("Roger that!")
-    [Mark says]: Roger that!
+    '[Mark says]: Roger that!'
     >>> ethan.say("Alright.")
-    [Ethan says]: Alright.
+    '[Ethan says]: Alright.'
     """
 
 

patterns/behavioral/memento.py

@@ -42,7 +42,7 @@ def rollback(self):
 
 
 class Transactional:
-    """Adds transactional semantics to methods. Methods decorated  with
+    """Adds transactional semantics to methods. Methods decorated with
 
     @Transactional will rollback to entry-state upon exceptions.
     """

patterns/behavioral/visitor.py

@@ -46,10 +46,10 @@ def visit(self, node, *args, **kwargs):
         return meth(node, *args, **kwargs)
 
     def generic_visit(self, node, *args, **kwargs):
-        print("generic_visit " + node.__class__.__name__)
+        return "generic_visit " + node.__class__.__name__
 
     def visit_B(self, node, *args, **kwargs):
-        print("visit_B " + node.__class__.__name__)
+        return "visit_B " + node.__class__.__name__
 
 
 def main():
@@ -58,13 +58,13 @@ def main():
     >>> visitor = Visitor()
 
     >>> visitor.visit(a)
-    generic_visit A
+    'generic_visit A'
 
     >>> visitor.visit(b)
-    visit_B B
+    'visit_B B'
 
     >>> visitor.visit(c)
-    visit_B C
+    'visit_B C'
     """
 
 

tests/behavioral/test_catalog.py

@@ -0,0 +1,23 @@
+import pytest
+
+from patterns.behavioral.catalog import Catalog, CatalogClass, CatalogInstance, CatalogStatic
+
+def test_catalog_multiple_methods():
+    test = Catalog('param_value_2')
+    token = test.main_method()
+    assert token == 'executed method 2!'
+
+def test_catalog_multiple_instance_methods():
+    test = CatalogInstance('param_value_1')
+    token = test.main_method()
+    assert token == 'Value x1'
+    
+def test_catalog_multiple_class_methods():
+    test = CatalogClass('param_value_2')
+    token = test.main_method()
+    assert token == 'Value x2'
+
+def test_catalog_multiple_static_methods():
+    test = CatalogStatic('param_value_1')
+    token = test.main_method()
+    assert token == 'executed method 1!'

tests/behavioral/test_mediator.py

@@ -0,0 +1,16 @@
+import pytest
+
+from patterns.behavioral.mediator import User
+
+def test_mediated_comments():
+    molly = User('Molly')
+    mediated_comment = molly.say("Hi Team! Meeting at 3 PM today.")
+    assert mediated_comment == "[Molly says]: Hi Team! Meeting at 3 PM today."
+
+    mark = User('Mark')
+    mediated_comment = mark.say("Roger that!")
+    assert mediated_comment == "[Mark says]: Roger that!"
+
+    ethan = User('Ethan')
+    mediated_comment = ethan.say("Alright.")
+    assert mediated_comment == "[Ethan says]: Alright."

tests/behavioral/test_memento.py

@@ -0,0 +1,29 @@
+import pytest
+
+from patterns.behavioral.memento import NumObj, Transaction
+
+def test_object_creation():
+    num_obj = NumObj(-1)
+    assert repr(num_obj) == '<NumObj: -1>', "Object representation not as expected"
+
+def test_rollback_on_transaction():
+    num_obj = NumObj(-1)
+    a_transaction = Transaction(True, num_obj)
+    for _i in range(3):
+        num_obj.increment()
+    a_transaction.commit()
+    assert num_obj.value == 2
+
+    for _i in range(3):
+        num_obj.increment()
+    try:
+        num_obj.value += 'x'  # will fail
+    except TypeError:
+        a_transaction.rollback()
+    assert num_obj.value == 2, "Transaction did not rollback as expected"
+
+def test_rollback_with_transactional_annotation():
+    num_obj = NumObj(2)
+    with pytest.raises(TypeError):
+        num_obj.do_stuff()
+    assert num_obj.value == 2

tests/behavioral/test_visitor.py

@@ -0,0 +1,22 @@
+import pytest
+
+from patterns.behavioral.visitor import A, B, C, Visitor
+
+@pytest.fixture
+def visitor():
+    return Visitor()
+
+def test_visiting_generic_node(visitor):
+    a = A()
+    token = visitor.visit(a)
+    assert token == 'generic_visit A', "The expected generic object was not called"
+
+def test_visiting_specific_nodes(visitor):
+    b = B()
+    token = visitor.visit(b)
+    assert token == 'visit_B B', "The expected specific object was not called"
+
+def test_visiting_inherited_nodes(visitor):
+    c = C()
+    token = visitor.visit(c)
+    assert token == 'visit_B C', "The expected inherited object was not called"