Implement the JSON representation for system tests

guix-data-service/web/revision/controller.scm

@@ -423,7 +423,22 @@
            mime-types)
       ((application/json)
        (render-json
-        '()))                           ; TODO
+        `((commit . ,commit-hash)
+          (system . ,(assq-ref query-parameters 'system))
+          (system_tests
+           . ,(list->vector
+               (map
+                (match-lambda
+                  ((name description file line column-number
+                         derivation-file-name builds)
+                   `((name . ,name)
+                     (description . ,description)
+                     (location . ((file . ,file)
+                                  (line . ,line)
+                                  (column-number . ,column-number)))
+                     (derivation . ,derivation-file-name)
+                     (builds . ,(list->vector builds)))))
+                system-tests))))))
       (else
        (render-html
         #:sxml (view-revision-system-tests

guix-data-service/web/revision/html.scm

@@ -868,6 +868,16 @@
                     (button (@ (type "submit")
                                (class "btn btn-lg btn-primary"))
                             "Update results")))))
+        (a (@ (class "btn btn-lg btn-default pull-right")
+              (href ,(let ((query-parameter-string
+                            (query-parameters->string query-parameters)))
+                       (string-append
+                        path-base ".json"
+                        (if (string-null? query-parameter-string)
+                            ""
+                            (string-append "?" query-parameter-string)))))
+              (role "button"))
+           "View JSON")
         (table
          (@ (class "table"))
          (thead