In Intellij Idea, how to run tests with different java version than my source java version

Question

My main source has java version 7

I want to use java 8 from my tests. so i updated the compiler plugin to

<plugin>
   <groupId>org.apache.maven.plugins</groupId>
   <artifactId>maven-compiler-plugin</artifactId>
   <version>3.8.1</version>
   <configuration>
      <source>7</source>
      <target>7</target>
      <testSource>8</testSource>
      <testTarget>8</testTarget>
   </configuration>
</plugin>

This way I can use java 8 features in unit tests. This works fine when i run the tests using maven from commandline.

But when i run the test directly from intellij, it throws error saying 'lambda expressions are not supported in source 7'

looks like it use the same source version for tests.

How do i configure Intellij to use different java version for tests

Answer 1

Running tests via another Java interpreter in Maven project is not supported in IntelliJ IDEA yet. Here is the feature request for that:

https://youtrack.jetbrains.com/issue/IDEA-85478

Feel free to vote and follow it for updates.

There is a workaround described by one of the users (separate Maven profile): https://youtrack.jetbrains.com/issue/IDEA-85478#focus=Comments-27-1994481.0-0

By the way, this is supported in Gradle<->IntelliJ IDEA integration:

compileTestJava {
    sourceCompatibility = "1.8"
}