-

cool-RR · cool-RR · commit 8b23f0abb9a1 · 2014-01-24T15:58:50.000+02:00
diff --git a/source_py3/python_toolbox/monkeypatching_tools.py b/source_py3/python_toolbox/monkeypatching_tools.py
@@ -12,7 +12,7 @@
 
 
 @decorator_tools.helpful_decorator_builder
-def monkeypatch_method(monkeypatchee, name=None):
+def monkeypatch_method(monkeypatchee, name=None, override_if_exists=True):
     '''
     Monkeypatch a method into a class (or an object).
     
@@ -48,8 +48,8 @@ def decorator(function):
             
             new_method = function if monkeypatchee_is_a_class else \
                              types.MethodType(function, class_of_monkeypatchee)
-            setattr(monkeypatchee, name_, new_method)
-            return function
+            setattr_value = new_method
+            return_value = function
         else:
             # `function` is probably some kind of descriptor.
             if not monkeypatchee_is_a_class:
@@ -76,8 +76,11 @@ def decorator(function):
                     )
                 #                                                             #
                 ### Finished getting name of descriptor. ######################
-            setattr(monkeypatchee, name_, function)
-            return function
+            setattr_value = return_value = function
+
+        if override_if_exists or not hasattr(monkeypatchee, name_):
+            setattr(monkeypatchee, name_, setattr_value)
+        return return_value
         
     return decorator
 
diff --git a/source_py3/test_python_toolbox/test_monkeypatching_tools.py b/source_py3/test_python_toolbox/test_monkeypatching_tools.py
@@ -22,6 +22,31 @@ def __eq__(self, other):
         return self is other
 
 
+    def test():
+        '''Test basic workings of `monkeypatch_method`.'''
+        
+        class A(EqualByIdentity):
+            pass
+    
+        @monkeypatching_tools.monkeypatch_method(A)
+        def meow(a):
+            return (a, 1)
+        
+        a = A()
+        
+        assert a.meow() == meow(a) == (a, 1)
+        
+        @monkeypatching_tools.monkeypatch_method(A, 'roar')
+        def woof(a):
+            return (a, 2)
+        
+        assert a.roar() == woof(a) == (a, 2)
+        
+        assert not hasattr(a, 'woof')
+        
+        del meow, woof
+        
+        
 def test():
     '''Test basic workings of `monkeypatch_method`.'''
     
@@ -47,6 +72,31 @@ def woof(a):
     del meow, woof
     
     
+def test_without_override():
+    
+    class A(EqualByIdentity):
+        def booga(self):
+            return 'Old method'
+
+    @monkeypatching_tools.monkeypatch_method(A, override_if_exists=False)
+    def meow(a):
+        return (a, 1)
+    
+    a = A()
+    
+    assert a.meow() == meow(a) == (a, 1)
+    
+    
+    @monkeypatching_tools.monkeypatch_method(A, override_if_exists=False)
+    def booga():
+        raise RuntimeError('Should never be called.')
+    
+    a = A()
+    
+    assert a.booga() == 'Old method'
+    
+    
+    
 def test_monkeypatch_property():
 
     class A(EqualByIdentity):
