lint: Warn about underscores in package names.

As per section '16.4.2 Package Naming' in the manual, use hyphens
instead of underscores in package names.

* guix/lint.scm (check-name): Check whether the package name contains
underscores.
* tests/lint.scm ("name: use underscore in package name"): New test.

Signed-off-by: Ludovic Courtès <ludo@gnu.org>

2 files changed, 23 insertions, 8 deletions

diff --git a/guix/lint.scm b/guix/lint.scm
index a7d6bbba4f..1bebfe03d3 100644
--- a/guix/lint.scm
+++ b/guix/lint.scm
@@ -11,6 +11,7 @@
 ;;; Copyright © 2018, 2019 Arun Isaac <arunisaac@systemreboot.net>
 ;;; Copyright © 2020 Chris Marusich <cmmarusich@gmail.com>
 ;;; Copyright © 2020 Timothy Sample <samplet@ngyro.com>
+;;; Copyright © 2021 Xinglu Chen <public@yoctocell.xyz>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -81,6 +82,7 @@
             check-synopsis-style
             check-derivation
             check-home-page
+            check-name
             check-source
             check-source-file-name
             check-source-unstable-tarball
@@ -173,14 +175,20 @@
 (define (check-name package)
   "Check whether PACKAGE's name matches our guidelines."
   (let ((name (package-name package)))
-    ;; Currently checks only whether the name is too short.
-    (if (and (<= (string-length name) 1)
-             (not (string=? name "r"))) ; common-sense exception
-        (list
-         (make-warning package
-                       (G_ "name should be longer than a single character")
-                       #:field 'name))
-        '())))
+    (cond
+     ;; Currently checks only whether the name is too short.
+     ((and (<= (string-length name) 1)
+           (not (string=? name "r"))) ; common-sense exception
+      (list
+       (make-warning package
+                     (G_ "name should be longer than a single character")
+                     #:field 'name)))
+     ((string-index name #\_)
+      (list
+       (make-warning package
+                     (G_ "name should use hyphens instead of underscores")
+                     #:field 'name)))
+     (else '()))))
 
 (define (properly-starts-sentence? s)
   (string-match "^[(\"'`[:upper:][:digit:]]" s))
diff --git a/tests/lint.scm b/tests/lint.scm
index bd8604f589..a2c8665142 100644
--- a/tests/lint.scm
+++ b/tests/lint.scm
@@ -8,6 +8,7 @@
 ;;; Copyright © 2017 Efraim Flashner <efraim@flashner.co.il>
 ;;; Copyright © 2018, 2019 Arun Isaac <arunisaac@systemreboot.net>
 ;;; Copyright © 2020 Timothy Sample <samplet@ngyro.com>
+;;; Copyright © 2021 Xinglu Chen <public@yoctocell.xyz>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -270,6 +271,12 @@
                             (description "Imagine this is Taylor UUCP."))))
     (check-synopsis-style pkg)))
 
+(test-equal "name: use underscore in package name"
+  "name should use hyphens instead of underscores"
+  (single-lint-warning-message
+   (let ((pkg (dummy-package "under_score")))
+     (check-name pkg))))
+
 (test-equal "inputs: pkg-config is probably a native input"
   "'pkg-config' should probably be a native input"
   (single-lint-warning-message