[bug#70482] [PATCH] guix: pyproject-build-system: Add python test-backend.

[Nicolas Graves via Guix-patches via <guix-patches@gnu.org>]

* guix/build/pyproject-build-system(check): Add python test-backend.

This will help in cases where a simple `python -m module args` call has
to be made instead of fully replacing the 'check phase, e.g. unittest
or django. This is never enabled unless #:test-backend 'python is set,
so it doesn't break anything.

As an example, the following snippet...

(arguments
  (list #:phases #~(modify-phases %standard-phases
                     (replace 'check
                       (lambda* (#:key tests? #:allow-other-keys)
                         (when tests?
                           (invoke "python" "-m" "unittest"
                                   "diff_match_patch.tests")))))))

...can be transformed like this: 

(arguments
  '(#:test-backend 'python
    #:test-flags (list "-m" "unittest" "diff_match_patch.tests")))

Change-Id: I4919a3e01d64864e3c328609fbcce7df5b3dfe51
---
 guix/build/pyproject-build-system.scm | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/guix/build/pyproject-build-system.scm b/guix/build/pyproject-build-system.scm
index c69ccc9d64..295542f317 100644
--- a/guix/build/pyproject-build-system.scm
+++ b/guix/build/pyproject-build-system.scm
@@ -168,6 +168,8 @@ (define* (check #:key tests? test-backend test-flags #:allow-other-keys)
                   (if (null? test-flags)
                       '("test" "-v")
                       test-flags)))
+          ('python
+           (apply invoke "python" test-flags))
           ;; The developer should explicitly disable tests in this case.
           (else (raise (condition (&test-system-not-found))))))
       (format #t "test suite not run~%")))
-- 
2.41.0