Zip up all of your source files (.java files) and upload them to the autograder. Subfolders are fine, the autograder will search and find all of your .java files. Make sure your folder/filenames do not contain spaces (or any other whitespace) in them.
I know some IDEs let you right-click your src folder, and then export them to a zip file, which should make submitting a little easier.
The autograder is built on openjdk11, please be careful to not use features from an incompatible version of jdk.
On this page, the input source files are available as “Gradescope Tests” for each programming assignment.
If, for example, the test named “pass145” does not result in a “Success” from your compiler, you can find pass145.java in the tests zip, and see what is going on in that source file.
Similarly, the test named “fail128” should fail syntax analysis, and correspond to fail128.java in the gradescope tests zip file.
The autograder will pass the full path of the test file in args[0], but your FileInputStream likely won’t care if it is a full or relative path. If you want to test offline, find your bin folder where .class files are, and do java -cp bin miniJava.Compiler /path/to/your/test/file.java