challenge: Add "--diff".

* guix/scripts/challenge.scm (dump-port*): New variable.
(archive-contents, store-item-contents, narinfo-contents)
(differing-files, report-differing-files): New procedures.
(summarize-report): Add #:report-differences and call it.
(show-help, %options): Add "--diff".
(%default-options): Add 'difference-report' key.
(report-differing-files): Parameterize CURRENT-TERMINAL-COLUMNS and pass
 #:report-differences to 'summarize-report'.
* guix/tests/http.scm (%local-url): Add optional argument.
(call-with-http-server): Fix docstring typo.
* tests/challenge.scm (query-path-size, make-narinfo): New procedures.
("differing-files"): New test.
* doc/guix.texi (Invoking guix challenge): Document "--diff".

1 files changed, 3 insertions, 3 deletions

diff --git a/guix/tests/http.scm b/guix/tests/http.scm
index 05ce39bca2..4119e9ce01 100644
--- a/guix/tests/http.scm
+++ b/guix/tests/http.scm
@@ -65,14 +65,14 @@ needed."
            (close-port socket)
            #t)))
 
-(define (%local-url)
+(define* (%local-url #:optional (port (%http-server-port)))
   ;; URL to use for 'home-page' tests.
-  (string-append "http://localhost:" (number->string (%http-server-port))
+  (string-append "http://localhost:" (number->string port)
                  "/foo/bar"))
 
 (define* (call-with-http-server responses+data thunk)
   "Call THUNK with an HTTP server running and returning RESPONSES+DATA on HTTP
-requests.  Each elements of RESPONSES+DATA must be a tuple containing a
+requests.  Each element of RESPONSES+DATA must be a tuple containing a
 response and a string, or an HTTP response code and a string."
   (define responses
     (map (match-lambda