STS 4.4.0 no longer runs JUnit5 Tests - STS 4.3.2 did not have a problem

[mdehner-drivin]

When I took STS 4.4.0 last Friday and ran my JUnit5 tests, I received this error:

java.lang.NoClassDefFoundError: org/junit/platform/commons/PreconditionViolationException
    at org.eclipse.jdt.internal.junit5.runner.JUnit5TestLoader.createUnfilteredTest(JUnit5TestLoader.java:75)
    at org.eclipse.jdt.internal.junit5.runner.JUnit5TestLoader.createTest(JUnit5TestLoader.java:66)
    at org.eclipse.jdt.internal.junit5.runner.JUnit5TestLoader.loadTests(JUnit5TestLoader.java:53)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:525)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:763)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:463)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:209)
Caused by: java.lang.ClassNotFoundException: org.junit.platform.commons.PreconditionViolationException
    at java.net.URLClassLoader.findClass(URLClassLoader.java:382)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:349)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    ... 7 more

The tests were working fine with version 4.3.2. The only non-base install plug-in I have is "EclEmma Java Code Coverage 3.1.2", so I tried removing that from my install in 4.4.0 and that did not resolve the issue. When I downgraded back to 4.3.2, I was able to successfully run my tests again.

My basic STS install details for 4.3.2 are attached.
STSInstallDetails.txt

[martinlippert]

Can you provide a sample project that could help us to reproduce the issue?

[mdehner-drivin]

Sure thing. I'll put a quick project together this afternoon and attach it.

[martinlippert]

@mdehner-drivin Awesome, looking forward to it. Thanks in advance!!!

[mdehner-drivin]

Here's what I did to create the attached ZIP:

1. Installed STS 4.4.0
2. Created a demo project using Spring Initializer. (Java 8, Maven)
3. Added the demo project into the default 4.4.0 workspace.
4. Imported the Maven project into STS Project Explorer like normal.
5. Updated the pom.xml to exclude JUnit4 and include the JUnit5 libraries like I have them in our various projects. Additionally, added various standard dependencies (including Swagger) so it's more like one of the projects I've been working on.
6. Renamed the application.properties file to application.yml and added minor configuration into it.
7. Updated the Initializer generated DemoApplicationTests class to be JUnit5 instead of JUnit4.
8. Ran DemoApplicationTests by right-clicking on the class, going to "Run As", selected "JUnit Test" and received the aforementioned stack trace.

I verified the "Test runner" is set to "JUnit 5" for the run configuration of DemoApplicationTests.

The attached is my entire workspace with the demo project included. Please let me know if any additional information is needed.
workspace-spring-tool-suite-4-4.4.0.RELEASE.zip

[BoykoAlex]

I debugged this a bit in e4.13 and e4.12 and I see the process being launched for tests having the same arguments including identical classpath entries. Seems like it is something with JDTs RemoteTestRunner or JUnit5TestLoader.
I can reproduce the issue with Eclipse 4.13 for Java Developers. Thus raised: https://bugs.eclipse.org/bugs/show_bug.cgi?id=551389

[yukihane]

Overriding junit-jupiter.version property value 5.3.2(Spring Boot 2.1.8 default) to 5.5.2, it seems to be resolved.

[spydesk]

Here is a workaround, when your project doesn't inherit from the spring-boot-parent and imports spring-boot-dependencies instead:

	<dependencyManagement>
		<dependencies>

			<dependency>
				<groupId>org.junit</groupId>
				<artifactId>junit-bom</artifactId>
				<version>5.5.2</version>
				<type>pom</type>
				<scope>import</scope>
			</dependency>

			<dependency>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-dependencies</artifactId>
				<version>2.1.8.RELEASE</version>
				<type>pom</type>
				<scope>import</scope>
			</dependency>

		</dependencies>
	</dependencyManagement>

[martinlippert]

@spydesk Thanks, Simon, for sharing the workaround here. Much appreciated!!!

[eutiagocosta]

Same problem here using gradle with spring boot 2.1.8 and Junit 5.5.2, unfortunately the solution is to migrate to IntelliJ =/

[spydesk]

Alternatively, if you can, upgrading your project to Spring Boot 2.2.0 resolves the issue as well.

[johanhammar]

I'm experiencing a similar problem in STS 4.5.0 while it used to work in STS 4.4.2.

My project is using Spring Boot 2.2.2 and JUnit 5.5.2. Running the unit tests results in

Error: Could not find or load main class org.eclipse.jdt.internal.junit.runner.RemoteTestRunner
Caused by: java.lang.ClassNotFoundException: org.eclipse.jdt.internal.junit.runner.RemoteTestRunner

No additional plugins installed and the project is imported in a new clean workspace. Running the same tests in STS 4.4.2 works as expected.

I can open a new issue if this is not the correct place to discuss this

[kdvolder]

@johanhammar I tried the following:

• create a "New Spring Starter" project with web and actuator defendnecies.
• Select the single test that comes with the project (it was called 'com.example.demo.DemoApplicationTests.contextLoads()').
• Run as JUnit test

=> runs fine

This was with latest CI build of STS 4.5.1 build for Eclipse Platform 4.15 (latest milestone).

So either this problem has already been fixed somehow (could be it was a issue with Eclipse 4.14), or it is something specific to your project.

To determine this, I wonder if you could try the latest STS distrubtion snapshot to check if it works for you. You can download it from here: http://dist.springsource.com/snapshot/STS4/nightly-distributions.html

If the problem still happens on nightly for Eclipse 4.15 then please provide as much information as possible about your specific setup (most notably, since we suspect it is something specific to your project that may be triggering the bug, please attach a sample project to help reproduce the issue).

[johanhammar]

Hi @kdvolder Thanks alot

I created a Spring Starter with the mentioned dependencies. The tests run fine both STS 4.5.0 and STS Nightly (4.5.1.CI-B2135) on Windows.

Running tests in my project in STS 4.5.0 fails with an exception, as mention in my post above. However, in STS Nightly (4.5.1.CI-B2135) the tests works again.

So, it could be some combination of something in my project and Eclipse 4.14. I'll keep you updated if I find something. Is there anyway I can debug this?

[mweirauch]

Dunno if the recent fix to m2e (1.15.0 snapshots) are already part of the 4.5.1CI builds. See here for another fix to junit5 stuff. Can't figure if this is related: https://bugs.eclipse.org/bugs/show_bug.cgi?id=551298