Unfinished Stubbing Detected in Mockito

Mockito Stubbing: Understanding the Rules

To prevent falling into the "Unfinished Stubbing" pit, let’s keep these rules of engagement in mind when using Mockito.

Finish Stubbing Before Moving

Every when() needs its partner in crime thenReturn(). It’s a "Bonnie and Clyde" sort of relationship.

when(mockObject.method()).thenReturn(result); // Bonnie and Clyde 👫
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Don't Try to Stub the Untouchable

Stay away from trying to stub final methods or classes. Just like you don't introduce your girlfriend to your ex. ❌💔

Avoid Overcomplicating

The nesting of method calls, sort of like Russian dolls, could lead to stubbing errors. Keep it simple – flat is better than nested!

when(mockObject.getObject().getValue()).thenReturn(value); // Complicated ⚠️
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A cleaner approach:

SomeObject mockObject = mock(SomeObject.class);
when(mockObject.getValue()).thenReturn(value); // Clean! 👍
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Navigating Through Traps

Let's take a look at some bear traps and how to avoid stepping on them.

The Flexible Approach: doReturn()

When dealing with void methods or spies, doReturn() offers more flexibility.

doReturn(result).when(mockObject).method(); // Like a yoga class! 🧘‍♂️
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Kotlin Stubbing

In Kotlin, stubbing may look different due to its language semantics. Treat it like a fun game of language translation. 🌍

on { mockObject.method() } doReturn value // Kotlin's way of mocking
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For void methods:

Mockito.`when`(mockObject.voidMethodCall()).then { Unit } // Kotlin's solution for mocking void methods
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Verify your Syntax

It's important to cross-check the Mockito syntax like a nitpicking grammar teacher.

Confirm it's the Right Method

Always double-check that you’re stubbing the correct methods. It's like packing the right clothes for your holiday. You wouldn’t want to pack a bikini for a skiing trip now, would you? 🩱🎿

Messages From the Future

Make use of detailed error messages from recent Mockito versions. They're like treasure maps leading you to the issue.

Implement Flexible Matching

Use any() and other matchers wisely to make your stubs more accepting. But remember, with great power comes great responsibility! 🕷️

when(mockObject.method(any())).thenReturn(result); // Use Matchers for flexibility
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Keep Your Mocks in Check

Make sure mocks are created in an appropriate scope and passed to the right targets. The scope is like the mock's passport – it has to be valid, or it won't be allowed to travel. 🛂🌍

Apply the Right Solution

Think of the most practical solution for your specific case – like choosing the right tool for a DIY project. You don't want to use a hammer to sew a button on a shirt, do you? 🛠️🧵