Hi there! This is a repo that contains an open-source subset of the autograder we'll be using for CS 131 - Spring 2023's course-long project: making an interpreter.

Using this repository / testing locally is entirely optional. It does not directly affect your grade. You are free to only submit to Gradescope!

This repository contains:

• the full source code for the autograder we deploy to Gradescope
• 10% of the test cases we evaluate your code on; these are the test cases that are public on Gradescope
  • each version of the project is in a v* folder;
  • the tests subdirectory contains source (.brewin), expected (.exp), and standard input (.in) files for programs that should interpret and run without errors
  • the fails subdirectory contains source (.brewin), expected (.exp), and standard input (.in) files for programs that should interpret successfully, but error

This repository does not contain:

• 90% of the test cases we evaluate your code on (until after the project is due)
• the plagiarism checker, which is closed-source
• the Docker configuration for the deployment; this is managed by Gradescope.
• canonical solutions for the past projects - those are in the project template repo

We'll note that with the current setup, we grant five seconds for each test case to run.

We've made a separate repository for project template code.

This grader uses features of Python 3.11. So, you must be running Python 3.11 locally.

Next, clone this repository and make it your working directory:

$ git clone
# or, with SSH
$ git clone [email protected]:UCLA-CS-131/spring-23-autograder.git
...
cd spring-23-autograder

Now, you're ready to test locally.

To test locally, you will additionally need a working implementation of the project; the minimum example is an interpreterv1.py/interpreterv2.py/interpreterv3.py that implements the Interpreter class.

Place this in the same directory as tester.py. Then, to test project 1,

$ python3 tester.py 1
Running 5 tests...
Running v1/tests/test_inputi.brewin...  PASSED
Running v1/tests/test_recursion1.brewin...  PASSED
Running v1/tests/test_set_field.brewin...  PASSED
Running v1/fails/test_if.brewin...  PASSED
Running v1/fails/test_incompat_operands1.brewin...  PASSED
5/5 tests passed.
Total Score:    100.00%

The output of this command is identical to what is visible on Gradescope pre-due date, and they are the same cases that display on every submission. If there is a discrepancy, please let the teaching team know!

Note: we also output the results of the terminal output to results.json.

If you're a student and you've found a bug - please let the TAs know (confidentially)! If you're able to provide a minimum-reproducible example, we'll buy you a coffee - if not more!

This code is distributed under the MIT License.

Have you used this code? We'd love to hear from you! Submit an issue or send us an email ([email protected]).