Mockito UnfinishedStubbingException with when().thenReturn()

Question

I am getting the error message Unfinished Stubbing detected here, when running the following code:

import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.*;
import org.mockito.Mock;
import org.powermock.api.mockito.PowerMockito;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.modules.junit4.PowerMockRunner;
import org.powermock.reflect.Whitebox;

@RunWith(PowerMockRunner.class)
public class PatchWriterTaskTest {
@Before
public void before() throws Exception {
    filePath = getFilePath();
    task = PowerMockito.spy(new PatchWriterTask());
    patchFilesName = new HashMap<Integer, String>();

    patchFilesName.put(1, "TCE_RDF_COVERED_DATA_REGION.sql");

    scriptPath = new File(filePath + "do_patch_rdf.sql");

    PowerMockito.when(task, "getLogger").thenReturn(logger);
    PowerMockito.when(task, "getPatchFilesName").thenReturn(patchFilesName);
    PowerMockito.when(task, "getDirectoryPath").thenReturn(filePath);
    PowerMockito.when(task, "saveDoPatchFile");
}
@Test
public void testUpdateIssuesTable() throws Exception {
        PatchWriterTask task = new PatchWriterTask();
        Connection conn = mock(Connection.class);
        PreparedStatement updateStatement = mock(PreparedStatement.class);
        String sql = "update val_issues set PATCH_CREATION_INFO = ? where VAL_ISSUE_ID = ?";
        when(conn.prepareStatement(sql)).thenReturn(updateStatement);

The last line throws the error. It doesn't really make sense, as I have done the same code before. Why am I getting this error?

EDIT: I am using powerMockito in order to use the Whitebox.invokeMethod() method, but I also want to use regular Mockito in the rest of the program. Could that be a problem?

Stack Trace:

org.mockito.exceptions.misusing.UnfinishedStubbingException: 
Unfinished stubbing detected here:
-> at org.powermock.api.mockito.PowerMockito.when(PowerMockito.java:426)

E.g. thenReturn() may be missing.
Examples of correct stubbing:
    when(mock.isOk()).thenReturn(true);
    when(mock.isOk()).thenThrow(exception);
    doThrow(exception).when(mock).someVoidMethod();
Hints:
 1. missing thenReturn()
 2. you are trying to stub a final method, you naughty developer!

    at com.navteq.rdf.base.task.PatchWriterTaskTest.testUpdateIssuesTable(PatchWriterTaskTest.java:78)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.junit.internal.runners.TestMethod.invoke(TestMethod.java:66)
    at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$PowerMockJUnit44MethodRunner.runTestMethod(PowerMockJUnit44RunnerDelegateImpl.java:310)
    at org.junit.internal.runners.MethodRoadie$2.run(MethodRoadie.java:86)
    at org.junit.internal.runners.MethodRoadie.runBeforesThenTestThenAfters(MethodRoadie.java:94)
    at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$PowerMockJUnit44MethodRunner.executeTest(PowerMockJUnit44RunnerDelegateImpl.java:294)
    at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$PowerMockJUnit44MethodRunner.runBeforesThenTestThenAfters(PowerMockJUnit44RunnerDelegateImpl.java:282)
    at org.junit.internal.runners.MethodRoadie.runTest(MethodRoadie.java:84)
    at org.junit.internal.runners.MethodRoadie.run(MethodRoadie.java:49)
    at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.invokeTestMethod(PowerMockJUnit44RunnerDelegateImpl.java:207)
    at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.runMethods(PowerMockJUnit44RunnerDelegateImpl.java:146)
    at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$1.run(PowerMockJUnit44RunnerDelegateImpl.java:120)
    at org.junit.internal.runners.ClassRoadie.runUnprotected(ClassRoadie.java:34)
    at org.junit.internal.runners.ClassRoadie.runProtected(ClassRoadie.java:44)
    at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.run(PowerMockJUnit44RunnerDelegateImpl.java:118)
    at org.powermock.modules.junit4.common.internal.impl.JUnit4TestSuiteChunkerImpl.run(JUnit4TestSuiteChunkerImpl.java:104)
    at org.powermock.modules.junit4.common.internal.impl.AbstractCommonPowerMockRunner.run(AbstractCommonPowerMockRunner.java:53)
    at org.powermock.modules.junit4.PowerMockRunner.run(PowerMockRunner.java:53)
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)

Are you statically importing `when` and `thenReturn` from different classes? E.g. one from PowerMock and one from Mockito? — Duncan Jones, Jun 24 '14 at 15:10
Looks like you might be hitting this: [Mockito UnfinishedStubbingException](http://stackoverflow.com/questions/15554119/mockito-unfinishedstubbingexception), since you are also returning a mocked object from within a `thenReturn` call. What version of Mockito are you using? — Duncan Jones, Jun 24 '14 at 15:14
@DanGordon Not 100% sure right now. I'm also struggling to reproduce this. Can you supply a complete code example, with version info, that reproduces this? — Duncan Jones, Jun 24 '14 at 15:23
Added the other code. the only thing I think could be causing a problem is `@RunWith(PowerMockRunner.class)` — DanGordon, Jun 24 '14 at 16:31
It seems weird that your stacktrace indicates that `PowerMockito.when` is causing the problem but your static imports are from `Mockito` — geoand, Jun 24 '14 at 17:43

score 8 · Answer 1 · answered Jan 23 '15 at 23:04

8

I wanted to add a note that I got this exact same exception, even though my code was written properly. It turned out to be entirely a runtime problem.

My code:

when(service.getChampionById(1, region, null, null)).thenReturn(championList.getChampion(1));

The exception:

org.mockito.exceptions.misusing.UnfinishedStubbingException: 
Unfinished stubbing detected here:
-> at ResourceV1bTest.setUpResources(ResourceV1bTest.java:2168)

E.g. thenReturn() may be missing.
Examples of correct stubbing:
    when(mock.isOk()).thenReturn(true);
    when(mock.isOk()).thenThrow(exception);
    doThrow(exception).when(mock).someVoidMethod();
Hints:
 1. missing thenReturn()
 2. you are trying to stub a final method, you naughty developer!

It turned out that the following call was throwing an exception, which then triggered the Mockito exception about unfinished stubbing.

championList.getChampion(1)

answered Jan 23 '15 at 23:04

Schmick

210
2
11

Also just bumped into this. Worth mentioning that you `championList` must be wrapped with `Mockito.spy()` earlier for this error to happen. When using a non-wrapped object, the error does not happen. Also, you can store the result of `getChampion(1)` in a variable to circumvent the error being triggered. – Philzen Feb 10 '22 at 02:34
Anyway i believe this is an undocumented error. Just tried with Mockito 4.3.1 and the problem persists. Or can anybody say whether this is actually documented behavior or an issue entry exists for this? – Philzen Feb 10 '22 at 02:36
There is actually an [excellent writeup on this behavior](http://speakman.net.nz/blog/2019/04/07/mockito-unfinishedstubbingexception-in-tests/), however it doesn't mention if that was really what the Mockito creators had in mind. Even if this was the intended behavior it may be very helpful to add a hint to the error message regarding this special case. – Philzen Feb 10 '22 at 02:40

score 2 · Accepted Answer · answered Jun 25 '14 at 22:57

Seems like the error is pretty clear.

PowerMockito.when(task, "saveDoPatchFile");

...is missing a thenReturn, right?

E.g. thenReturn() may be missing. Examples of correct stubbing:
    when(mock.isOk()).thenReturn(true);
    when(mock.isOk()).thenThrow(exception);
    doThrow(exception).when(mock).someVoidMethod();

So why is the exception down in your test method? Neither PowerMock nor Mockito can flag a failure to call thenReturn until the next time you interact with (Power)Mockito or a mock. After all, Mockito and PowerMockito aren't notified that your @Before method ends, and have to accept the "waiting for thenReturn" state. (You're allowed to call mock before thenReturn to allow thenReturn(mock(Foo.class)).)

Wow yes that is exactly the problem. Can't believe I missed that. Not sure who wrote that code. It is odd that the exception is later on, but when I commented out `PowerMockito.when(task, "saveDoPatchFile");`, there was no error anymore — DanGordon, Jun 26 '14 at 15:14

Mockito UnfinishedStubbingException with when().thenReturn()

2 Answers2

Linked