java: OutOfMemoryError: insufficient memory while running JUnits in Idea

Question

I am trying to run JUnits from my IntelliJ Idea When I try to run the Test.java file it gives me an error saying that

java: OutOfMemoryError: insuffic

Answer 1

Idea runs unit tests in a separate java process.

You need to use

Run -> Edit Configurations...

and add your -XmxNNNm to VM Options.

For example:

-ea -Xmx1024m

The "-ea" means "enable assertions".

If your unit test(s) can't run in a 1GB of memory then it's possible that you have a memory leak.

Answer 2

As this OOM happened during compilation, you need to increase compile VM:

Answer 3

In my case, my SpringBootTest configuration has Build (whole project) gradle task in "Before launch". So that's my omission. Eliminating that and issue's gone away.

Or Settings -> Compiler : increase build heap size

Answer 4

To increase heap size is one option. For me (using subversion for source version control) it was even easier to unload some of the modules which I had checked out and where not directly used for the test. This will also speed up the build process for future tests.

Right click on any module in the project-area of IntelliJ -> Load/Unload modudules -> Choose one/some bigger module and move to the "unload" area.

Answer 5

Based on your log the problem is in compiler heap space.

Go to

Settings -> Compiler -> Build process heap size (MB)

and increase that value.