packages: Add `package-output'.

* guix/packages.scm (package-output): New procedure.
* tests/packages.scm ("package-output"): New test.

1 files changed, 8 insertions, 1 deletions

diff --git a/tests/packages.scm b/tests/packages.scm
index 32ee558518..f441532d22 100644
--- a/tests/packages.scm
+++ b/tests/packages.scm
@@ -71,7 +71,7 @@
                    ("d" ,d) ("d/x" "something.drv"))
                  (pk 'x (package-transitive-inputs e))))))
 
-(test-skip (if (not %store) 3 0))
+(test-skip (if (not %store) 4 0))
 
 (test-assert "return values"
   (let-values (((drv-path drv)
@@ -79,6 +79,13 @@
     (and (derivation-path? drv-path)
          (derivation? drv))))
 
+(test-assert "package-output"
+  (let* ((package  (dummy-package "p"))
+         (drv-path (package-derivation %store package)))
+    (and (derivation-path? drv-path)
+         (string=? (derivation-path->output-path drv-path)
+                   (package-output %store package "out")))))
+
 (test-assert "trivial"
   (let* ((p (package (inherit (dummy-package "trivial"))
               (build-system trivial-build-system)