I have a resource abc/xyz.json under src/test/resources. I'm using IntelliJ IDE.
While running a Test for my project, I get the following exception.
Exception
com.google.common.io.Resources.getResource("abc/xyz.json")
fails with java.lang.IllegalArgumentException: resource abc/xyz.json not found.
The Test runs fine with gradle clean build and eclipse

Had the same issue not that long ago, since Intellij outputs the class files into
out/production/{project_name}, that path will not start in thesrcdirectory but will start in theout/production/{project_name}directory.It will however see files that are in the project root directory, I'd recommend moving your resource directory into the main project directory then accessing the file with
"resources\${FILE_NAME}".