"No junit.jar" error in Intellij when right clicking a folder, but not when running individual classes of tests

My Spring boot application has several tests classes.

When right-clicking a test class, and selecting the option to Run XYZtest it works with no problem.

But when selecting the folder that contains that class and selecting Run test in com.example.my I get an error of No junit.jar:

When running all the tests from mvn they run with no problems.

Following some suggestions, I added the junit.jar specifically in the Library section, but it didn't help:

I met this problem, this is how I soloved it:

Context:

• SpringBoot application
• Use maven to manage multiple modules
• Add junit's maven dependency in root POM's dependencyManagement(rather than dependencies, their differences can be found here)
• Intend to test class or folder inside one of the root module's child module

PS: If your situation does not match the context above, this solution may not solve your problem.

Steps

1. right click at the class or folder you want to test:
   
2. Choose More Run/Debug -> Modify Run Configuration
3. Change the module option to the one you want to test from root module
   

Spring boot is using JUnit 5. If you use the spring boot initializr website, you should have a dependency like this.

<dependency>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-test</artifactId>
		<scope>test</scope>
		<exclusions>
			<exclusion>
				<groupId>org.junit.vintage</groupId>
				<artifactId>junit-vintage-engine</artifactId>
			</exclusion>
		</exclusions>
	</dependency>

Did you use JUnit 4 or 5 in your tests ? You can try to update IntelliJ or JUnit plugin, this may solve your problem.

I managed to solve the issue by adding the Junit Maven dependancy in the root pom.xml file.