PowerMockito: got InvalidUseOfMatchersException when use matchers mocking static method

Question

When I\'m testing this static method

public class SomeClass {
    public static long someMethod(Map map, String string, Long l, Log log) {
        ...
    }
         


        

Answer 1

<dependency>
        <groupId>org.mockito</groupId>
        <artifactId>mockito-all</artifactId>
        <version>${mockito.version}</version>
    </dependency>
    <dependency>
        <groupId>org.powermock</groupId>
        <artifactId>powermock-module-junit4</artifactId>
        <version>${powermock.version}</version>
        <type>jar</type>
        <scope>provided</scope>
    </dependency>
    <dependency>
        <groupId>org.powermock</groupId>
        <artifactId>powermock-api-mockito</artifactId>
        <version>${powermock.version}</version>
        <type>jar</type>
        <scope>provided</scope>
    </dependency>

I hope your project is using maven. Try including these jars to the build.

Answer 2

Better late than never, the line below:

Mockito.when(SomeClass.someMethod(anyMap(), anyString(), anyLong(),
    isA(Log.class))).thenReturn(1L);

should be:

PowerMockito.when(SomeClass.someMethod(anyMap(), anyString(), anyLong(),
    isA(Log.class))).thenReturn(1L);

So, instead of invoking Mockito.when, one should invoke PowerMockito.when

Answer 3

Try replacing the isA() to another any() call like this

Mockito.when(SomeClass.someMethod(anyMap(), anyString(), anyLong(), any(Log.class))).thenReturn(1L);

[EDIT]

Check your stacktrace when you get the exception. Are you seeing any NoClassDefFoundError reported? I noticed when I hadn't included the javassist.jar in my project I got a similar error to you.

I use PowerMockito and these are the jars I added to a brand new project to run the code that @Tom posted

• powermock-mockito-1.4.10-full.jar
• mockito-all-1.8.5.jar
• javassist-3.15.0-GA.jar
• junit-4.8.2.jar
• common-logging-1.1.1.jar

Always a good idea to check that you're using compatible JAR versions, and also check if there are any other conflicting JARs in your projects classpath.

Answer 4

1. isA will always return null. This is by design, it is documented in the Javadoc for the isA() method. The reason for this is that null will always match the parameterized return type of class, which will always match the type of the argument in the stubbed method for which the isA() Matcher is used. The null value which is returned is not actually acted upon.

2. Seems to work fine for me. My complete test case:

import static org.mockito.Matchers.*;

import java.util.Map;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.impl.SimpleLog;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.Mockito;
import org.powermock.api.mockito.PowerMockito;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.modules.junit4.PowerMockRunner;

class SomeClass {
  public static long someMethod(final Map map, final String string, final Long l, final Log log) {
    return 2L;
  }
}

@RunWith(PowerMockRunner.class)
@PrepareForTest(SomeClass.class)
public class InvalidUseOfMatchersTest {
    @Test
    public void test() {
        // Mock the SomeClass' static methods, stub someMethod() to return 1
        PowerMockito.mockStatic(SomeClass.class);
        Mockito.when(SomeClass.someMethod(anyMap(), anyString(), anyLong(), isA(Log.class))).thenReturn(1L);

        // null NOT is-a Log, uses default stubbing: returns 0
        System.out.println(SomeClass.someMethod(null, null, 5L, null));
        // SimpleLog passes is-a test, uses stubbed result: returns 1
        System.out.println(SomeClass.someMethod(null, null, 7L, new SimpleLog("simplelog")));
    }
}

Perhaps post a complete example to help diagnose what's going on?