Add a (tests driver) module

Using the test driver from build-aux/test-driver.scm, as this shows the test
errors when tests fail.

Makefile.am

@@ -56,7 +56,8 @@ SOURCES =							\
   guix-data-service/web/sxml.scm				\
   guix-data-service/web/query-parameters.scm			\
   guix-data-service/web/util.scm				\
-  guix-data-service/web/view/html.scm
+  guix-data-service/web/view/html.scm				\
+  tests/driver.scm
 
 TEST_EXTENSIONS = .scm
 

tests/driver.scm

@@ -0,0 +1,115 @@
+;;; Copyright © 2015, 2016 Mathieu Lirzin <mthl@gnu.org>
+;;; Copyright © 2019 Christopher Baines <mail@cbaines.net>
+;;;
+;;; This program is free software; you can redistribute it and/or modify it
+;;; under the terms of the GNU General Public License as published by
+;;; the Free Software Foundation; either version 3 of the License, or (at
+;;; your option) any later version.
+;;;
+;;; This program is distributed in the hope that it will be useful, but
+;;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;;; GNU General Public License for more details.
+;;;
+;;; You should have received a copy of the GNU General Public License
+;;; along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+(define-module (tests driver)
+  #:use-module (ice-9 pretty-print)
+  #:use-module (srfi srfi-26)
+  #:use-module (srfi srfi-64)
+  #:export (setup-runner))
+
+(define* (test-display field value  #:optional (port (current-output-port))
+                       #:key pretty?)
+  "Display \"FIELD: VALUE\\n\" on PORT."
+  (if pretty?
+      (begin
+        (format port "~A:~%" field)
+        (pretty-print value port #:per-line-prefix "+ "))
+      (format port "~A: ~S~%" field value)))
+
+(define* (result->string symbol #:key colorize?)
+  "Return SYMBOL as an upper case string.  Use colors when COLORIZE is #t."
+  (let ((result (string-upcase (symbol->string symbol))))
+    (if colorize?
+        (string-append (case symbol
+                         ((pass)       "")  ;green
+                         ((xfail)      "")  ;light green
+                         ((skip)       "")  ;blue
+                         ((fail xpass) "")  ;red
+                         ((error)      "")) ;magenta
+                       result
+                       "")          ;no color
+        result)))
+
+(define* (test-runner-gnu #:key color? brief? out-port trs-port)
+  "Return an custom SRFI-64 test runner.  COLOR? specifies whether to use colors,
+and BRIEF?, well, you know.  OUT-PORT and TRS-PORT must be output ports.  The
+current output port is supposed to be redirected to a '.log' file."
+
+  (define (test-on-test-begin-gnu runner)
+    ;; Procedure called at the start of an individual test case, before the
+    ;; test expression (and expected value) are evaluated.
+    (let ((result (cute assq-ref (test-result-alist runner) <>)))
+      (format #t "location: ~A~%"
+              (string-append (result 'source-file) ":"
+                             (number->string (result 'source-line))))
+      (test-display "source" (result 'source-form) #:pretty? #t)))
+
+  (define (test-on-test-end-gnu runner)
+    ;; Procedure called at the end of an individual test case, when the result
+    ;; of the test is available.
+    (let* ((results (test-result-alist runner))
+           (result? (cut assq <> results))
+           (result  (cut assq-ref results <>)))
+      (unless brief?
+        ;; Display the result of each test case on the console.
+        (format out-port "~A: ~A~%"
+                (result->string (test-result-kind runner) #:colorize? color?)
+                (test-runner-test-name runner)))
+      (when (result? 'expected-value)
+        (test-display "expected-value" (result 'expected-value)))
+      (when (result? 'expected-error)
+        (test-display "expected-error" (result 'expected-error) #:pretty? #t))
+      (when (result? 'actual-value)
+        (test-display "actual-value" (result 'actual-value)))
+      (when (result? 'actual-error)
+        (test-display "actual-error" (result 'actual-error) #:pretty? #t))
+      (format #t "result: ~a~%" (result->string (result 'result-kind)))
+      (newline)
+      (format trs-port ":test-result: ~A ~A~%"
+              (result->string (test-result-kind runner))
+              (test-runner-test-name runner))))
+
+  (define (test-on-group-end-gnu runner)
+    ;; Procedure called by a 'test-end', including at the end of a test-group.
+    (let ((fail (or (positive? (test-runner-fail-count runner))
+                    (positive? (test-runner-xpass-count runner))))
+          (skip (or (positive? (test-runner-skip-count runner))
+                    (positive? (test-runner-xfail-count runner)))))
+      ;; XXX: The global results need some refinements for XPASS.
+      (format trs-port ":global-test-result: ~A~%"
+              (if fail "FAIL" (if skip "SKIP" "PASS")))
+      (format trs-port ":recheck: ~A~%"
+              (if fail "yes" "no"))
+      (format trs-port ":copy-in-global-log: ~A~%"
+              (if (or fail skip) "yes" "no"))
+      (when brief?
+        ;; Display the global test group result on the console.
+        (format out-port "~A: ~%"
+                (result->string (if fail 'fail (if skip 'skip 'pass))
+                                #:colorize? color?)))
+      #f))
+
+  (let ((runner (test-runner-null)))
+    (test-runner-on-test-begin! runner test-on-test-begin-gnu)
+    (test-runner-on-test-end! runner test-on-test-end-gnu)
+    (test-runner-on-group-end! runner test-on-group-end-gnu)
+    (test-runner-on-bad-end-name! runner test-on-bad-end-name-simple)
+    runner))
+
+(define (setup-runner)
+  (test-runner-current (test-runner-gnu)))
+
+(setup-runner)