Could not initialize plugin: interface org.mockito.plugins.MockMaker

Question

I\'m getting following exception once tests is started:

    Testcase: treeCtorArgumentTest(com.xythos.client.drive.cachedtree.CachedTreeTest):  Caused an ERR         


        

Answer 1

Remove version declaration works for me:

Example:

    <dependency>
        <groupId>org.mockito</groupId>
        <artifactId>mockito-core</artifactId>
        <version>2.8.9</version>
        <scope>test</scope>
    </dependency>

remove 2.8.9

After:

    <dependency>
        <groupId>org.mockito</groupId>
        <artifactId>mockito-core</artifactId>
        <scope>test</scope>
    </dependency>

It may due to version issue between jar packages of this dependency.

Answer 2

Missing reference to:

• byte-buddy-1.6.5.jar
• byte-buddy-agent-1.6.5.jar
• objenesis-2.5.jar

Since Mockito 2.0.2 beta, Mockito-core has dependencies.

Answer 3

Just update to the latest release of org.mockito:mockito-core. Once I did, the errors disappeared!

Answer 4

This problem with Mockito2 occurs if you enable the option to mock final classes.

This means when in your test/resources/mockito-extensions directory you have the file called org.mockito.plugins.MockMaker with the following content mock-maker-inline.

In that case byte-buddy, which is a transitive dependency for mockito-core, has the problem to attach own agent to the java process. But the problem occurs only when you use JRE.

The solution would be either:

• Use JDK instead of JRE

or

• add -javaagent:byte-buddy-agent-*.jar as a VM option

Answer 5

Mockito 2 requires dependencies. Adding the two ByteBuddy dependencies below. solved the issue for me:

• byte-buddy-x.x.xx.jar
• byte-buddy-agent-x.x.xx.jar

In my case I include jar files in the project, which can be found at: https://bintray.com/raphw/maven/ByteBuddy/

If you need it for a Maven project, simply add:

<dependency>
  <groupId>net.bytebuddy</groupId>
  <artifactId>byte-buddy</artifactId>
  <version>1.9.14</version>
  <type>pom</type>
</dependency>

Answer 6

For me the problem was that IntelliJ ran the test as integration test. So I needed to create JUnit test manually