[bug#36351] [PATCH 01/10] derivations: Add 'derivation-input'.

["Ludovic Courtès" <ludo@gnu.org>]

* guix/derivations.scm (derivation-input): New procedure.
* tests/grafts.scm (make-derivation-input): Remove.
("graft-derivation, unused outputs not depended on"): Use
'derivation-input'.
---
 guix/derivations.scm |  8 ++++++++
 tests/grafts.scm     | 16 ++++------------
 2 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/guix/derivations.scm b/guix/derivations.scm
index 8145d51143..4df7b06181 100644
--- a/guix/derivations.scm
+++ b/guix/derivations.scm
@@ -157,6 +157,14 @@
   "Return the <derivation> object INPUT refers to."
   (read-derivation-from-file (derivation-input-path input)))
 
+(define* (derivation-input drv #:optional
+                           (outputs (derivation-output-names drv)))
+  "Return a <derivation-input> for the OUTPUTS of DRV."
+  ;; This is a public interface meant to be more convenient than
+  ;; 'make-derivation-input' and giving us more control.
+  (make-derivation-input (derivation-file-name drv)
+                         outputs))
+
 (set-record-type-printer! <derivation>
                           (lambda (drv port)
                             (format port "#<derivation ~a => ~a ~a>"
diff --git a/tests/grafts.scm b/tests/grafts.scm
index f85f3c6913..6fd3d5e171 100644
--- a/tests/grafts.scm
+++ b/tests/grafts.scm
@@ -1,5 +1,5 @@
 ;;; GNU Guix --- Functional package management for GNU
-;;; Copyright © 2014, 2015, 2016, 2017, 2018 Ludovic Courtès <ludo@gnu.org>
+;;; Copyright © 2014, 2015, 2016, 2017, 2018, 2019 Ludovic Courtès <ludo@gnu.org>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -45,9 +45,6 @@
 (define %mkdir
   (bootstrap-binary "mkdir"))
 
-(define make-derivation-input
-  (@@ (guix derivations) make-derivation-input))
-
 \f
 (test-begin "grafts")
 
@@ -356,16 +353,11 @@
                 (p1r-inputs  (filter (match-input p1r) inputs))
                 (p2-inputs   (filter (match-input p2) inputs)))
            (and (equal? p1-inputs
-                        (list (make-derivation-input (derivation-file-name p1)
-                                                     '("one"))))
+                        (list (derivation-input p1 '("one"))))
                 (equal? p1r-inputs
-                        (list
-                         (make-derivation-input (derivation-file-name p1r)
-                                                '("ONE"))))
+                        (list (derivation-input p1r '("ONE"))))
                 (equal? p2-inputs
-                        (list
-                         (make-derivation-input (derivation-file-name p2)
-                                                '("aaa"))))
+                        (list (derivation-input p2 '("aaa"))))
                 (derivation-output-names p2g))))))
 
 (test-assert "graft-derivation, renaming"         ;<http://bugs.gnu.org/23132>
-- 
2.22.0