静态类模拟中的org.powermock.api.mockito.ClassNotPreparedException

Question

I am writing a unit test to mock a static method in the verticle but getting ClassNotPreparedException always. I think that its only possible to mock this way if only the class is static, but i have non static class. What am i missing?

I have tried various solutions like using @rule or @PowerMockIgnore

//myVerticleTest.java

package com.blabla.me.verticles;
import static com.google.common.truth.Truth.assertThat;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
import io.vertx.core.Vertx;
import io.vertx.junit5.VertxTestContext;
import io.vulpx.VulpxTestBase;
import org.powermock.api.mockito.PowerMockito;
import org.powermock.core.classloader.annotations.PowerMockIgnore;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.modules.junit4.PowerMockRunner;
import org.junit.runner.RunWith;
import com.blabla.me.verticles.AdditionalInformationCardVerticle;
import org.powermock.modules.junit4.rule.PowerMockRule;
import org.junit.Rule;
import com.blabla.me.verticles.st;

@RunWith(PowerMockRunner.class)
@PrepareForTest({ st.class })
@PowerMockIgnore({"org.mockito.*"})
public class myVerticleTest extends VulpxTestBase {
@Rule public PowerMockRule rule = new PowerMockRule();
private Vertx vertx;
private AdditionalInformationCardVerticle dummy;

    @BeforeEach
    @PrepareForTest({ st.class })
    public void setUp(VertxTestContext testContext) throws Exception {
        vertx = Vertx.vertx();
        try {
            PowerMockito.mockStatic(st.class);
            PowerMockito.when(st.createClient()).thenReturn("kk");
         //deploying verticle
            dummy = new AdditionalInformationCardVerticle();
            vertx.deployVerticle(dummy, testContext.completing());
        } catch (Exception e) {
            System.out.println("heyyy eroorrr : " + e);
        }
    }
    @Test
    @PrepareForTest({ st.class })
    public void justnormaltest() {
        cla ownclass = new cla();
        String k = ownclass.createfromclass();
        assertThat("kk").isEqualTo(k);
    }
}

// st.java 
public class st {
    public static String createClient() {
        return "kk";
    }
}

// cla.java
public class cla {
    public String createfromclass() {
        return st.createClient();
    }
}

I expect it to run the assertion but i always get below excpetion: "org.powermock.api.mockito.ClassNotPreparedException: The class com.sap.me.verticles.st not prepared for test. To prepare this class, add class to the '@PrepareForTest' annotation. In case if you don't use this annotation, add the annotation on class or method level. "

Answer 1

Here:

@PrepareForTest({ st.class })

That one goes to exactly one place: in front of your test class public class myVerticleTest .

And hint: instead of adding more and more "things" to not working code: pick any good documentation, and try to follow that to the last ; in the example code (instead of assuming that adding more and more things here or there would help).

One good starting point: the official documentation on static mocking.

And of course, the usual caveat: consider not learning about PowerMock in the first place. Instead focus on writing "easy to test" code. Far too often, people think PowerMock(ito) is the answer to their problem. When their problem in reality is their inability to write "easy to test" production code.