org.junit.platform.commons.JUnitException: TestEngine with ID 'junit-jupiter' failed to discover tests

Question

I wan to implement a Junit 5 test into Gradle project. I tried this:

Gradle configuration:

plugins {
    id 'org.springframework.boot' version '2.5.5'
    id 'io.spring.dependency-management' version '1.0.11.RELEASE'
    id 'java'
}

group = 'test'
version = '0.0.1'
sourceCompatibility = '17'

repositories {
    mavenCentral()
}

ext {
    set('springCloudVersion', "2020.0.4")
}

dependencies {
    ...............
    testImplementation 'org.springframework.boot:spring-boot-starter-test'
    testImplementation 'org.junit.jupiter:junit-jupiter-api:5.8.2'
    testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine:5.8.2'
}

dependencyManagement {
    imports {
        mavenBom "org.springframework.cloud:spring-cloud-dependencies:${springCloudVersion}"
    }
}

test {
    useJUnitPlatform()
}

Junit test:

import org.junit.jupiter.api.DisplayName;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.Timeout;

import java.util.concurrent.TimeUnit;

public class GeneratePdf {

    @DisplayName("Test MessageService.get()")
    @Test
    @Timeout(value = 60, unit = TimeUnit.SECONDS)
    public void generatePdfFileTes() throws InterruptedException
    {
        System.out.println("test!");
    }

}

When I run the code I get error:

Internal Error occurred.
org.junit.platform.commons.JUnitException: TestEngine with ID 'junit-jupiter' failed to discover tests
    at org.junit.platform.launcher.core.EngineDiscoveryOrchestrator.discoverEngineRoot(EngineDiscoveryOrchestrator.java:160)
    at org.junit.platform.launcher.core.EngineDiscoveryOrchestrator.discoverSafely(EngineDiscoveryOrchestrator.java:134)
    at org.junit.platform.launcher.core.EngineDiscoveryOrchestrator.discover(EngineDiscoveryOrchestrator.java:108)
    at org.junit.platform.launcher.core.EngineDiscoveryOrchestrator.discover(EngineDiscoveryOrchestrator.java:80)
    at org.junit.platform.launcher.core.DefaultLauncher.discover(DefaultLauncher.java:110)
    at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:86)
    at org.junit.platform.launcher.core.DefaultLauncherSession$DelegatingLauncher.execute(DefaultLauncherSession.java:86)
    at org.junit.platform.launcher.core.SessionPerRequestLauncher.execute(SessionPerRequestLauncher.java:53)
    at com.intellij.junit5.JUnit5IdeaTestRunner.startRunnerWithArgs(JUnit5IdeaTestRunner.java:71)
    at com.intellij.rt.junit.IdeaTestRunner$Repeater$1.execute(IdeaTestRunner.java:38)
    at com.intellij.rt.execution.junit.TestsRepeater.repeat(TestsRepeater.java:11)
    at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:35)
    at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:235)
    at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:54)
Caused by: org.junit.platform.commons.JUnitException: MethodSelector [className = 'org.merchant.poc.GeneratePdf', methodName = 'generatePdfFileTes', methodParameterTypes = ''] resolution failed
    at org.junit.platform.launcher.listeners.discovery.AbortOnFailureLauncherDiscoveryListener.selectorProcessed(AbortOnFailureLauncherDiscoveryListener.java:39)
    at org.junit.platform.engine.support.discovery.EngineDiscoveryRequestResolution.resolveCompletely(EngineDiscoveryRequestResolution.java:102)
    at org.junit.platform.engine.support.discovery.EngineDiscoveryRequestResolution.run(EngineDiscoveryRequestResolution.java:82)
    at org.junit.platform.engine.support.discovery.EngineDiscoveryRequestResolver.resolve(EngineDiscoveryRequestResolver.java:113)
    at org.junit.jupiter.engine.discovery.DiscoverySelectorResolver.resolveSelectors(DiscoverySelectorResolver.java:46)
    at org.junit.jupiter.engine.JupiterTestEngine.discover(JupiterTestEngine.java:69)
    at org.junit.platform.launcher.core.EngineDiscoveryOrchestrator.discoverEngineRoot(EngineDiscoveryOrchestrator.java:152)
    ... 13 more
Caused by: org.junit.platform.commons.PreconditionViolationException: Could not load class with name: org.merchant.poc.GeneratePdf
    at org.junit.platform.engine.discovery.MethodSelector.lambda$lazyLoadJavaClass$0(MethodSelector.java:157)
    at org.junit.platform.commons.function.Try$Failure.getOrThrow(Try.java:335)
    at org.junit.platform.engine.discovery.MethodSelector.lazyLoadJavaClass(MethodSelector.java:156)
    at org.junit.platform.engine.discovery.MethodSelector.getJavaClass(MethodSelector.java:135)
    at org.junit.jupiter.engine.discovery.MethodSelectorResolver.resolve(MethodSelectorResolver.java:73)
    at org.junit.platform.engine.support.discovery.EngineDiscoveryRequestResolution.lambda$resolve$2(EngineDiscoveryRequestResolution.java:146)
    at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:197)
    at java.base/java.util.ArrayList$ArrayListSpliterator.tryAdvance(ArrayList.java:1602)
    at java.base/java.util.stream.ReferencePipeline.forEachWithCancel(ReferencePipeline.java:129)
    at java.base/java.util.stream.AbstractPipeline.copyIntoWithCancel(AbstractPipeline.java:527)
    at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:513)
    at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:499)
    at java.base/java.util.stream.FindOps$FindOp.evaluateSequential(FindOps.java:150)
    at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
    at java.base/java.util.stream.ReferencePipeline.findFirst(ReferencePipeline.java:647)
    at org.junit.platform.engine.support.discovery.EngineDiscoveryRequestResolution.resolve(EngineDiscoveryRequestResolution.java:185)
    at org.junit.platform.engine.support.discovery.EngineDiscoveryRequestResolution.resolve(EngineDiscoveryRequestResolution.java:125)
    at org.junit.platform.engine.support.discovery.EngineDiscoveryRequestResolution.resolveCompletely(EngineDiscoveryRequestResolution.java:91)
    ... 18 more
Caused by: java.lang.ClassNotFoundException: org.merchant.poc.GeneratePdf
    at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:641)
    at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:188)
    at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:520)
    at org.junit.platform.commons.util.ReflectionUtils.lambda$tryToLoadClass$9(ReflectionUtils.java:829)
    at org.junit.platform.commons.function.Try.lambda$call$0(Try.java:57)
    at org.junit.platform.commons.function.Try.of(Try.java:93)
    at org.junit.platform.commons.function.Try.call(Try.java:57)
    at org.junit.platform.commons.util.ReflectionUtils.tryToLoadClass(ReflectionUtils.java:792)
    at org.junit.platform.commons.util.ReflectionUtils.tryToLoadClass(ReflectionUtils.java:748)
    ... 34 more

Do you know how this issue can be fixed?

EDIT:

import org.junit.jupiter.api.Test;

public class InvoiceTests {

    @Test
    public void generateTest()
    {
        System.out.println("test!");
    }

}

I tried this but again it's not working.

Judging from the stacktrace "java.lang.ClassNotFoundException: org.merchant.poc.GeneratePdf" something in your setup seems to be wrong. Might be conflicting versions or source paths or a few other things. If a clean build doesn't help, I suggest you create a minimum reproducing repo and link it here, so that others can recreate the effect. — johanneslink, Dec 23 '21 at 09:53

score 34 · Answer 1 · edited Oct 03 '22 at 18:08

34

I had this issue when I upgraded the versions of JUnit from 5.7.0 to 5.8.2. Try with version 5.7.0 for org.junit.jupiter:junit-jupiter-api and org.junit.jupiter:junit-jupiter-engine

edited Oct 03 '22 at 18:08

Ele

33,468
7
37
75

answered Jan 22 '22 at 00:01

Kowlown

920
10
26

5

Same. Do we know what the difference in 5.8.2 is that's causing this? – Antony Stubbs Mar 30 '22 at 12:02
2

Thanks this helped. This was the solution to my problem when I upgraded from spring boot 2.5.10 to 2.6.5 – Younes El Ouarti Apr 04 '22 at 03:56
yes, It was working for me also, Eclipse version Version: 2022-03 (4.23.0) Build id: 20220310-1457, Changed to 5.7.0 Thanks. – Gaganam Krishna Aug 18 '22 at 04:54
Thanks! Also worked for me with via Intellij runner (Intellij Ultimate 2022.2.3) and also with Apache Ant 1.10.10 – Max M Oct 21 '22 at 14:37

score 13 · Answer 2 · answered Apr 09 '22 at 11:48

13

Environment :

IntelliJ
Java 17

I have faced the same issue after upgrading my project from JDK 11 to JDK 17 and junit-jupiter-api from 5.7.0 to 5.8.2.

On my project, the working version is 5.7.2

Follow the issue here : Github issue

answered Apr 09 '22 at 11:48

AceneKASDI

339
3
8

score 8 · Accepted Answer · edited Jun 07 '22 at 15:41

What is the project structure you are following? I remember facing a similar issue when I started out, so basically what I did was just follow this structure:

project-dir
 -- src
     -- main
        -- java
            -- classes
     -- test
        -- java
            -- test-classes

In addition to the above structure, make sure you are naming your test classes in a correct format as mentioned in the answer by @johanneslink

score 5 · Answer 4 · answered Oct 21 '22 at 14:51

5

In my case, a mvn clean compile helped.

answered Oct 21 '22 at 14:51

Valerij Dobler

1,848
15
25

score 3 · Answer 5 · answered Dec 22 '21 at 21:35

3

GeneratePdf does not match the default name pattern for test classes. The default pattern is Test*|*Test|*Tests.

You can change it in your Gradle file with

test {
  useJUnitPlatform()
  include '**/*Pdf'
}

answered Dec 22 '21 at 21:35

johanneslink

4,877
1
20
37

I tried to change the names(see the post) but again it's not working. – Peter Penzov Dec 22 '21 at 21:54

score 3 · Answer 6 · answered Aug 30 '22 at 03:28

3

adding this dependency alone will fix this issue. I tried with 5.6.2, any version is fine

testImplementation('org.junit.jupiter:junit-jupiter:5.6.2')

answered Aug 30 '22 at 03:28

Karthi J

51
5

This worked for me with Kotlin 1.7.10 and JDK 17.0.4. But these other jupiter versions did not work: 5.6.3, 5.7.0, 5.7.2, 5.8.2,5.9.1 – devdanke Oct 17 '22 at 12:03

score 2 · Answer 7 · answered Feb 16 '22 at 06:28

2

I got the same error because I'd named my integration test class as XyzIT, post renaming it to XyzIntegrationTest, it started working.

answered Feb 16 '22 at 06:28

ADJ

1,182
2
14
26

3

Maven uses two different plugins. For integrationtests (ending in `IT`) maven uses `maven-failsafe-plugin` and for usual unit tests maven uses `maven-surefire-plugin` – Valerij Dobler Mar 23 '23 at 10:28
@ValerijDobler ok, so how else could I have fixed my error for ITs? – ADJ Mar 28 '23 at 15:00

score 2 · Answer 8 · answered Sep 06 '22 at 13:45

I had to add this in order for it to play nice with spring-boot-starter-test and JDK 17

    ext['junit-jupiter.version'] = '5.9.0'

Note: this is in addition to normal test dependencies and test task configuration.

Note2: AFAIK name requirements for test classes and test method and public visibility don't apply anymore with junit5 (no public class MyClassTest, public void mymethodTest())

Reference here

score 1 · Answer 9 · answered Dec 08 '22 at 12:30

1

JUnit libraries versions you specify must match JUnit POMs.

I got this error during routine dependency upgrade. I upgraded junit-jupiter-api and junit-jupiter-engine to 5.8.2 but left junit-platform-engine and junit-platform-commons pinned to 1.7.2. After some experiments I opened JUnit POM and found out that 5.8.2 uses 1.8.2 dependency. That was the reason. Always check that related dependencies are in sync!

answered Dec 08 '22 at 12:30

Aleksandr Kravets

5,750
7
53
72

Thanks - This got me onto the solution - not sure how but my junit-platform-engine dependency (coming in transiently) was at a higher version than junit-jupiter-api. Making sure those were the same major/minor solved my issue. – djchapm Aug 29 '23 at 01:59

score 1 · Answer 10 · answered Feb 06 '23 at 00:15

If your IDE is IntelliJ, check if you've set the directory as a Test.

Here this directory isn't marked as a Test Source, so the icon color is gray, and the folders are fully filled.

This is the way to mark the directory as a Test Source.

Now, the directory is marked a Test Source, changing the color, and the icon for the other folders, and now the IDE can recognise the tests inside the directory :)

score 0 · Answer 11 · answered Aug 16 '22 at 14:12

0

I was receiving such exception because had dependencies to both junit4 and junit5, removing junit4 solved the problem.

answered Aug 16 '22 at 14:12

Idriz Mustafa

61
1
2

score 0 · Answer 12 · answered Sep 23 '22 at 15:53

junit-jupiter-engine is a part of junit-jupiter add junit-jupiter from enter link description here in your pom.xml

for Example:

<!-- https://mvnrepository.com/artifact/org.junit.jupiter/junit-jupiter -->
<dependency>
    <groupId>org.junit.jupiter</groupId>
    <artifactId>junit-jupiter</artifactId>
    <version>5.9.1</version>
    <scope>test</scope>
</dependency>

score 0 · Answer 13 · answered Nov 19 '22 at 15:42

In my case I have

    <dependency>
        <groupId>org.junit.jupiter</groupId>
        <artifactId>junit-jupiter-engine</artifactId>
        <version>5.9.0</version>
        <scope>test</scope>
    </dependency>

with

    <properties>
    <java.version>17</java.version>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <maven.compiler.source>11</maven.compiler.source>
    <maven.compiler.target>${maven.compiler.source}</maven.compiler.target>
    <junit.jupiter.version>5.8.2</junit.jupiter.version>
    <junit.platform.version>1.8.2</junit.platform.version>
</properties>

I simply removed

<dependency>
        <groupId>org.junit.jupiter</groupId>
        <artifactId>junit-jupiter-engine</artifactId>
        <version>5.9.0</version>
        <scope>test</scope>
    </dependency>

And everything worked well!!

score 0 · Answer 14 · answered Nov 21 '22 at 07:58

For me, this problem happened for me when adding the junit-platform-suite-engine:1.9.1 dependency. By using gradle dependencies, as shown below, you can see that the 1.9.1 version causes a conflict between the junit versions set by spring boot.

|    +--- org.junit.jupiter:junit-jupiter:5.8.2
|    |    +--- org.junit:junit-bom:5.8.2 -> 5.9.1
|    |    |    +--- org.junit.jupiter:junit-jupiter:5.9.1 -> 5.8.2 (c)
|    |    |    +--- org.junit.jupiter:junit-jupiter-api:5.9.1 -> 5.8.2 (c)
|    |    |    +--- org.junit.jupiter:junit-jupiter-engine:5.9.1 -> 5.8.2 (c)
|    |    |    +--- org.junit.jupiter:junit-jupiter-params:5.9.1 -> 5.8.2 (c)
|    |    |    +--- org.junit.platform:junit-platform-engine:1.9.1 -> 1.8.2 (c)
|    |    |    +--- org.junit.platform:junit-platform-suite-api:1.9.1 -> 1.8.2 (c)
|    |    |    +--- org.junit.platform:junit-platform-suite-commons:1.9.1 -> 1.8.2 (c)
|    |    |    +--- org.junit.platform:junit-platform-suite-engine:1.9.1 (c)
|    |    |    +--- org.junit.platform:junit-platform-launcher:1.9.1 -> 1.8.2 (c)
|    |    |    \--- org.junit.platform:junit-platform-commons:1.9.1 -> 1.8.2 (c)

To solve this, either remove the version from the dependency like below

testImplementation("org.junit.platform:junit-platform-suite-engine")

Or use the same version as spring boot (i.e., 1.8.2 in my case)

testImplementation("org.junit.platform:junit-platform-suite-engine:1.8.2")

score 0 · Answer 15 · answered Jan 13 '23 at 02:24

My case was different and might help someone.

I had converted a Java project to Spring boot project. Before doing this, I had imported junit-jupiter-engine dependency in my pom file.

I had to remove the junit-jupiter-engine dependency from the project and had to annotate my tests with:

@RunWith(SpringRunner.class)
@FixMethodOrder(value = MethodSorters.NAME_ASCENDING)

score 0 · Answer 16 · answered Apr 29 '23 at 14:36

I initially used mvn clean package - it worked fine. But then, when I run it with mvn verify - it failed.

Java 20 Junit jupiter api 5.9.2

The solutions is simple, I have renamed the file from ClassNameIntegrationTest.java to ClassNameIT.java it did the trick!

score 0 · Answer 17 · answered May 02 '23 at 20:28

0

If you didn't configure a database of your application, remove the @AutoConfigureTestDatabase annotation from test classes as it can throw the exception. As you remove it, you don't have to downgrade JUnit to version 5.7.0.

answered May 02 '23 at 20:28

Petr Kireev

1
3

score 0 · Answer 18 · answered Jul 12 '23 at 12:09

0

End up getting java.lang.NoSuchMethodError error so found this link to solve the issue.

answered Jul 12 '23 at 12:09

Aziz Zoaib

661
8
21

score -1 · Answer 19 · edited Dec 26 '22 at 22:36

-1

testImplementation('org.junit.jupiter:junit-jupiter:5.9.0')

edited Dec 26 '22 at 22:36

starball

20,030
7
43
238

answered Dec 26 '22 at 12:14

Carlos Noé

103
3
11

2

It would be nice to give a brief explanation of how this works / how it solves the problem, and how it's different than existing answers. – starball Dec 26 '22 at 22:35

score -1 · Answer 20 · answered Dec 27 '22 at 10:04

-1

Incorrect package path was my reason for this issue. Fixing the package path resolved the issue.

[package path present on the top of the java class] package <>

answered Dec 27 '22 at 10:04

Supreet Singh

1

Sadegh Firoozandeh · Answer 21 · 2023-04-19T17:26:04.250

-1

All of such issues had magically gone away after I did the following:

1- open the "Maven" tool window in IntelliJ IDEA. 2- execute "test". 3- then try again to run your unit tests.

It started to work for me.

edited Apr 19 '23 at 17:26

answered Apr 19 '23 at 17:17

Sadegh Firoozandeh

1
1

org.junit.platform.commons.JUnitException: TestEngine with ID 'junit-jupiter' failed to discover tests

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