RackUnit Grade🔗ℹ

This manual provides documentation for a simple Racket package for locally grading homework using RackUnit tests and a new raco grade command.

1 RackUnit Grade🔗ℹ

1.1 Installation🔗ℹ

If you have not installed the package yet, run the following command from the command-line:

  raco pkg install rackunit-grade

Note that this package will require Racket v6.0 or newer to install.

Alternatively, you may use the GUI package manager from DrRacket to install the package.

1.2 Creating a Grading File🔗ℹ

To use RackUnit Grade, you first write a grading file, containing all required libraries, and all the tests you want to run. It is recommended to define an individual test-suite for each specific exercise in your homework. For example, let us consider the tests.rkt file, which defines tests for the my-power function:

(require rackunit)

(require rackunit/grade)

(define-test-suite tests-my-power

(check-equal? (my-power 10 2) (expt 10 2))

(check-equal? (my-power 13 56) (expt 13 56)))

(define (my-result-handler results failures numtests suite-name)

(printf "~a got ~a failures out of ~a tests" suite-name failures numtests))

(evaluate-exercise tests-my-power my-result-handler)

In this case, we are evaluating function my-power, by testing it against the reference implementation expt. After defining the tests, we need to call evaluate-exercise.

• results: the results object as used in fold-test-results.

• failures: the number of tests that failed.

• numtests: the total number of tests.

• suite-name: the name of the test-suite.

2 Grading Student Files🔗ℹ

Now let us consider the homework.rkt file, which contains the solution from a student:

(provide my-power)

(define (my-power base power) 0)

Clearly this definition is wrong. Now, to combine the grading file with the student solution we need to use the new raco command raco grade:

  raco grade homework.rkt tests.rkt

This command will generate a new file grade_homework_tests.rkt in the current directory, which is a simple copy of tests.rkt appended with a (require "homework.rkt") form. Also the new file is run, using dynamic-require. In order for this schema to work, it is required that student files provide all functions that are going to be graded.