bug#50299: [PATCH v4 01/25] lint: check-tests-true: Allow #:tests? #t for some build systems.

[Maxime Devos <maximedevos@telenet.be>]

emacs-build-system sets #:tests? #f by default, so the linter
shouldn't warn if #:tests? #t is set for packages using
emacs-build-system.  Likewise for texlive-build-system

* guix/lint.scm (check-tests-true): Do not warn if the build system
  is emacs-build-system or texlive-build-system.
* tests/lint.scm
  ("tests-true: #:tests? #t acceptable for emacs packages")
  ("tests-true: #:tests? #t acceptable for texlive packages"): New tests.

Fixes: <https://issues.guix.gnu.org/50299>
Reported-by: Maxim Cournoyer <maxim.cournoyer@gmail.com>
---
 guix/lint.scm  | 11 +++++++++++
 tests/lint.scm | 21 +++++++++++++++++++++
 2 files changed, 32 insertions(+)

diff --git a/guix/lint.scm b/guix/lint.scm
index 379bd0e80b..8655f3aea7 100644
--- a/guix/lint.scm
+++ b/guix/lint.scm
@@ -34,6 +34,7 @@
   #:use-module (guix store)
   #:autoload   (guix base16) (bytevector->base16-string)
   #:use-module (guix base32)
+  #:use-module (guix build-system)
   #:use-module (guix diagnostics)
   #:use-module (guix download)
   #:use-module (guix ftp-client)
@@ -279,6 +280,16 @@ superfluous when building natively and incorrect when cross-compiling."
              (eq? tests? #t))
            (package-arguments package)))
   (if (and (tests-explicitly-enabled?)
+           ;; emacs-build-system sets #:tests? #f by default, therefore
+           ;; writing #:tests? #t in package definitions using
+           ;; emacs-build-system is reasonable.  Likewise for
+           ;; texlive-build-system.
+           ;;
+           ;; Compare the name of the build system instead of the build system
+           ;; itself to avoid loading unnecessary modules when only a few
+           ;; modules are linted.
+           (not (memq (build-system-name (package-build-system package))
+                      '(emacs texlive)))
            ;; Some packages, e.g. gnutls, set #:tests?
            ;; differently depending on whether it is being
            ;; cross-compiled.
diff --git a/tests/lint.scm b/tests/lint.scm
index 76c2a70b3a..6bb24370da 100644
--- a/tests/lint.scm
+++ b/tests/lint.scm
@@ -35,6 +35,8 @@
   #:use-module (guix tests http)
   #:use-module (guix download)
   #:use-module (guix git-download)
+  #:use-module (guix build-system texlive)
+  #:use-module (guix build-system emacs)
   #:use-module (guix build-system gnu)
   #:use-module (guix packages)
   #:use-module (guix lint)
@@ -338,6 +340,25 @@
                              `(#:tests? ,(not (%current-target-system)))))))
     (check-tests-true pkg)))
 
+;; The emacs-build-system sets #:tests? #f by default.
+(test-equal "tests-true: #:tests? #t acceptable for emacs packages"
+  '()
+  (let ((pkg (dummy-package "x"
+                            (build-system emacs-build-system)
+                            (arguments
+                             `(#:tests? #t)))))
+    (check-tests-true pkg)))
+
+;; Likewise, though the 'check' phase is deleted by default,
+;; so #:tests? #t won't be useful by itself.
+(test-equal "tests-true: #:tests? #t acceptable for texlive packages"
+  '()
+  (let ((pkg (dummy-package "x"
+                            (build-system texlive-build-system)
+                            (arguments
+                             `(#:tests? #t)))))
+    (check-tests-true pkg)))
+
 (test-equal "inputs: pkg-config is probably a native input"
   "'pkg-config' should probably be a native input"
   (single-lint-warning-message
-- 
2.30.2