Using Mockito's generic "any()" method

Digging the treasure - Mockito's any()

With Mockito in your testing toolkit, any() is a wildcard that indicates your nonchalance towards specific arguments in your mocked methods. It's significantly useful when you want to ensure that a method is called but you don't care what gifts it brings. Penis mightier than the sword, right?

Playing nice with types and generics

any() is a method generous with its welcomes, extending its arms wide to any type entering the mocking game. However, when you're dealing with generics or specific types, any(Class<T> clazz) is much more graceful, sidestepping unnecessary pitfalls and maintaining type safety. They say anyObject() is a crowd-pleaser for generics but he's the bad boy of the mock world - deprecated and notorious for surprise cleanup bills.

// 'anyObject()' left gym at 2AM, found sleeping in the park...deprecated now 
verify(mock).aRandomMethod(any(MyClass.class)); 
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Beware of Autoboxing: Save yourself from autoboxing drama using specific matchers like anyInt(), you might trip on unexpected nulls or performance bills.

// We don't want Charlie boxed in a factory...
verify(mock).someMethodWithPrimitiveArg(anyInt()); 
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Code tug-of-war: Arrays vs interfaces

Comes a time when you're trapped between matching an array type and asserting that a method is called. My friend, isA() got your back:

// No one puts baby in a corner
verify(mock).methodWithArrayArg(isA(Foo[].class)); 
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Keeping up with the Mockito

Always keep your owns on version updates. Matchers is the new black, and ArgumentMatchers is the hot selling summer collection. Staying updated means you're prepared for future releases and your code won't embarrass itself at parties.

Behind the veil of any():

For the love of static imports

Static imports are the haute couture in the town of readability and brevity. After all, who likes typing org.mockito.ArgumentMatchers.any?

import static org.mockito.Mockito.*;
import static org.mockito.ArgumentMatchers.*;

// Who needs prescription glasses anyway?
verify(mock).someLoremIpsumMethod(any()); 
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Precision over wild guessing

any(), times and again proves to be a valuable asset when you’re indifferent about certain parameters. But there are times when you should be specific. Tread the pouring rain with eq(), argThat(), or custom matchers.

// Precision gives clarity to your tests, and your tests give clarity to your code.
when(mock.someMethod(eq("expected"))).thenReturn("response");
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The art of Mockito documentation

Stay in touch with the ever-evolving world of Mockito. Updated Mockito practices ensure your tests are always resilient and don’t wither with time.

The dark side of any()

The ghost of generics

Due to Java generics and their type erasure manners, it becomes critical to use any(Class<T> clazz) when you need to be specific about types in your mocks.

// It's not a dating app, can't just accept anyone.
when(mock.someMethod(any(List.class))).thenReturn("response");
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The habit of overusing

While any() can let you free your worries, remember to keep it on a leash. Make use of the most specific matcher that you can to ensure your mocks behave as expected.