Logging Output from Racket Tests to File

Question

I'm trying to set up a server to run extensive random tests against a Racket program, and want to have output from these tests sent to logs in files. How can I log output from tests to a file?

Tests from rackunit return #<void>, not a string, so trying to use (call-with-output-file ... with the tests only adds #<void> to the output file.

(call-with-output-file "testing.txt"
    (λ (out)
      (display <TESTS> out))
  #:exists 'append)

The output file should log the test results or errors if there are any. Any help is appreciated.

Answer 1

Instead of running checks by themselves, which print to stderr and return #<void>, put the checks in a test suite, so that you can use run-tests from rackunit/text-ui.

#lang racket
(require rackunit rackunit/text-ui)

(define-test-suite testing
  <TESTS>)

(.... something something (run-tests testing) ....)

However, the run-tests function seems to use current-error-port, not current-output-port, to print test failures, so within your call-with-output-file, you need to set the current-error-port to out.

(call-with-output-file "testing.txt"
  (λ (out)
    (parameterize ([current-error-port out])
      (run-tests testing)))
  #:exists 'append)