[JAVA] I got an InvalidUseOfMatchersException when using any with JUnit Mock

Introduction

I got an InvalidUseOfMatchersException when using any () from Matchers with Mockito in JUnit. I will summarize the solution.

Symptoms

I wrote a test code like this.

@Test
public void testDoSomething() {
    Hoge hoge = mock(Hoge.class)
    when(hoge.doSomething(any(), "bar")).thenReturn(true);
}

Since the first argument of hoge.doSomething () was a class defined by ourselves, we put ʻorg.mockito.Matchers.any ()`. The second argument is a String type and contains a specific character string.

When I ran the test in this state, I got the following Exception.

org.mockito.exceptions.misusing.InvalidUseOfMatchersException: 
Invalid use of argument matchers!
5 matchers expected, 3 recorded:
-> at hogehoge
-> at hogehoge
-> at hogehoge

This exception may occur if matchers are combined with raw values:
    //incorrect:
    someMethod(anyObject(), "raw String");
When using matchers, all arguments have to be provided by matchers.
For example:
    //correct:
    someMethod(anyObject(), eq("String by matcher"));

For more info see javadoc for Matchers class.

analysis

When using matchers, all arguments have to be provided by matchers.

As far as I read this error message, it seems that all the arguments need to be in matchers format. For String type arguments, it seems good to use ʻeq () `.

Solution

when(hoge.doSomething(any(), "bar")).thenReturn(true);

I changed the above code as follows and the Exception no longer occurs.

when(hoge.doSomething(any(), eq("bar"))).thenReturn(true);

at the end

I was saved by a polite error message that details the solution. Matchers is good.