Mocking final classes

[ghost]

Hi,
Kotlin classes are final by default, when i use this library to test kotlin classes, it gives me the following error:

org.mockito.exceptions.base.MockitoException: 
Cannot mock/spy class com.app.network.entity.Movies
Mockito cannot mock/spy because :
 - final class

How do i test this? Please assist

[ZakTaccardi]

Use mock-maker-inline to mock final classes

[ghost]

I did that but i still get the error. Not sure what else might be missing.

…

On Fri, Sep 7, 2018 at 8:04 AM Zak Taccardi ***@***.***> wrote: Use mock-maker-inline <https://github.com/mockito/mockito/wiki/What%27s-new-in-Mockito-2#mock-the-unmockable-opt-in-mocking-of-final-classesmethods> to mock final classes — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#285 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AE2GzHVS_DpwxckaJBCCyf61GAqbpXPPks5uYcYpgaJpZM4WcORA> .

[bohsen]

Could you create a MWE for your issue? It's always easier to help if you have a bit more details.

[nhaarman]

Using mock-maker-inline should fix the issue, perhaps you've misconfigured it? See the original repo for details.

[bbaldino]

I started seeing this when upgrading to mockito-kotlin2. I've got mock-maker-inline set up (and was working fine with mockito-kotlin 1.5.0), but after upgrading to v2 I'm seeing:

Caused by: org.mockito.exceptions.base.MockitoException:
Mockito cannot mock this class: class org.jitsi.jibri.util.OsDetector.
Can not mock final classes with the following settings :
 - explicit serialization (e.g. withSettings().serializable())
 - extra interfaces (e.g. withSettings().extraInterfaces(...))

The class that causes it is final, but has no special settings that I know of:

enum class OsType {
    MAC,
    LINUX,
    UNSUPPORTED
}

class OsDetector {
    fun getOsType(): OsType {
        return when (System.getProperty("os.name")) {
            "Mac OS X" -> OsType.MAC
            "Linux" -> OsType.LINUX
            else -> OsType.UNSUPPORTED
        }
    }
}

[manerfan]

I started seeing this when upgrading to mockito-kotlin2. I've got mock-maker-inline set up (and was working fine with mockito-kotlin 1.5.0), but after upgrading to v2 I'm seeing:

Caused by: org.mockito.exceptions.base.MockitoException:
Mockito cannot mock this class: class org.jitsi.jibri.util.OsDetector.
Can not mock final classes with the following settings :
 - explicit serialization (e.g. withSettings().serializable())
 - extra interfaces (e.g. withSettings().extraInterfaces(...))

The class that causes it is final, but has no special settings that I know of:

enum class OsType {
    MAC,
    LINUX,
    UNSUPPORTED
}

class OsDetector {
    fun getOsType(): OsType {
        return when (System.getProperty("os.name")) {
            "Mac OS X" -> OsType.MAC
            "Linux" -> OsType.LINUX
            else -> OsType.UNSUPPORTED
        }
    }
}

try to add

<dependency>
    <groupId>net.bytebuddy</groupId>
    <artifactId>byte-buddy</artifactId>
    <scope>test</scope>
</dependency>

to the dependencies

[meganzhao10]

I started seeing this when upgrading to mockito-kotlin2. I've got mock-maker-inline set up (and was working fine with mockito-kotlin 1.5.0), but after upgrading to v2 I'm seeing:

Caused by: org.mockito.exceptions.base.MockitoException:
Mockito cannot mock this class: class org.jitsi.jibri.util.OsDetector.
Can not mock final classes with the following settings :
 - explicit serialization (e.g. withSettings().serializable())
 - extra interfaces (e.g. withSettings().extraInterfaces(...))

The class that causes it is final, but has no special settings that I know of:

enum class OsType {
    MAC,
    LINUX,
    UNSUPPORTED
}

class OsDetector {
    fun getOsType(): OsType {
        return when (System.getProperty("os.name")) {
            "Mac OS X" -> OsType.MAC
            "Linux" -> OsType.LINUX
            else -> OsType.UNSUPPORTED
        }
    }
}

try to add

<dependency>
    <groupId>net.bytebuddy</groupId>
    <artifactId>byte-buddy</artifactId>
    <scope>test</scope>
</dependency>

to the dependencies

I have the same error message when mocking JWTVerifier class (Java, not Kotlin), but adding the bytebuddy dependency doesn't solve the issue for me. This seems like a limitation of Mockito (Section 39: https://www.javadoc.io/doc/org.mockito/mockito-core/2.2.7/org/mockito/Mockito.html#Mocking_Final). Is there any way to bypass it?

Mockito cannot mock this class: class com.auth0.jwt.JWTVerifier.
Can not mock final classes with the following settings :
 - explicit serialization (e.g. withSettings().serializable())
 - extra interfaces (e.g. withSettings().extraInterfaces(...))

public final class JWTVerifier implements com.auth0.jwt.interfaces.JWTVerifier {
    private final Algorithm algorithm;
    final Map<String, Object> claims;
    private final Clock clock;
    private final JWTParser parser;

    JWTVerifier(Algorithm algorithm, Map<String, Object> claims, Clock clock) {
        this.algorithm = algorithm;
        this.claims = Collections.unmodifiableMap(claims);
        this.clock = clock;
        this.parser = new JWTParser();
    }

    static Verification init(Algorithm algorithm) throws IllegalArgumentException {
        return new JWTVerifier.BaseVerification(algorithm);
    }

    public DecodedJWT verify(String token) throws JWTVerificationException {
        DecodedJWT jwt = new JWTDecoder(this.parser, token);
        return this.verify((DecodedJWT)jwt);
    }

    public DecodedJWT verify(DecodedJWT jwt) throws JWTVerificationException {
        this.verifyAlgorithm(jwt, this.algorithm);
        this.algorithm.verify(jwt);
        this.verifyClaims(jwt, this.claims);
        return jwt;
    }
    ...
}

[bohsen]

@meganzhao10 A lot has changed since mockito-kotlin 1.5.0. This looks like a problem related to the creation of your mock.

Could you please share the test.

[meganzhao10]

@bohsen This is the test file. I'm able to run the tests successfully in IntelliJ. But mvn test failed with the message that I think it's part of Mockito limitations:

class ControllerTest {

    private Controller controller;

    @Mock
    private JWTVerifier verifier;

    @BeforeEach
    void setUp() {
        initMocks(this);
        controller = new Controller(verifier);
    }

    @Test
    void testFunc1() {
        ...
    }
    ...
}

I also included the pom.xml dependencies if that's helpful

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.9.10.3</version>
        </dependency>
        <dependency>
            <groupId>io.lettuce</groupId>
            <artifactId>lettuce-core</artifactId>
            <version>5.2.1.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>com.auth0</groupId>
            <artifactId>java-jwt</artifactId>
            <version>3.9.0</version>
        </dependency>
        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter-engine</artifactId>
            <version>${junit-jupiter.version}</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>com.github.stefanbirkner</groupId>
            <artifactId>system-rules</artifactId>
            <version>1.17.2</version>
        </dependency>
        <dependency>
            <groupId>org.mockito</groupId>
            <artifactId>mockito-core</artifactId>
            <version>2.24.0</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.mockito</groupId>
            <artifactId>mockito-junit-jupiter</artifactId>
            <version>${mockito.version}</version>
            <scope>test</scope>
        </dependency>
    </dependencies>

[bohsen]

@meganzhao10 Have you tried including mockito-inline artifact in your dependencies?

[bohsen]

@meganzhao10 If the Controller only has a dependency on the abstraction com.auth0.jwt.interfaces.JWTVerifier then I don't see any reason why this shouldn't work.

[meganzhao10]

@bohsen You're right that it should have worked. I built a Java container - the test passes with the base image 3.6.3-jdk-11-slim but failed with 3.6.3-jdk-14-slim. Then I switched my Java version from 14 to 11 and mvn test works, though I'm not sure it why the mock doesn't work with Java 14

[bohsen]

@meganzhao10 Maybe share this with the original Mockito project? I'm not sure if their CI test suite tests against java 14, but IMO it would make sense to create an issue on this.

[nmattocks-pfizer]

This looks like it's tracked mockito/mockito#2436
Commenting because this ranks higher on Google search.