WIP: do not merge: tests for relative dates

Hello,

unfortunately with my limited elisp knowledge, I am unable to write
succesful tests.

Maybe is possible to fake the current time for the current test. Faking
org-today is not enough?

My idea is that org-read-date return the date relative to the date of
the test instead of the day of the agenda that we want to test.

I think some steps are wrong/missing/incomplete:

- [ ] why ad-set-argument fails?
- [ ] use cl-letf with/instead of advice
- [ ] calculate the constant org-super-agenda-test-date-internal at runtime
- [ ] remove verbose message code
- [ ] save the correct test results

test/test.el

@@ -18,6 +18,8 @@
 ;;;; Variables
 
 (defconst org-super-agenda-test-date "2017-07-05 12:00")
+;; (org-read-date t t org-super-agenda-test-date))
+(defconst org-super-agenda-test-date-internal '(22876 47264))
 (defvar org-super-agenda-test-results (ht-create))
 (defvar org-super-agenda-test-save-results nil)
 (defvar org-super-agenda-test-show-results nil)
@@ -58,6 +60,19 @@
 (defun org-super-agenda-test--diary-sunset ()
   (cl-second (org-super-agenda-test--diary-sunrise-sunset-split)))
 
+
+;;;; Relative dates
+
+(defun org-read-date-get-relative-hack (orig-fun &rest args)
+  ;; (defun org-read-date-get-relative (s today default)
+  (message "first called with args %s" args)
+  (ad-set-argument 'args 1 org-super-agenda-test-date-internal)
+  (ad-set-argument 'args 2 org-super-agenda-test-date-internal)
+  (message "then calling with args %s" args)
+  (let ((res (apply orig-fun args)))
+    (message "returned %s" res)
+    res))
+
 ;;;; Commands
 
 (cl-defun org-super-agenda-test--update-all ()
@@ -530,10 +545,25 @@ already loaded."
   (should (org-super-agenda-test--run
            :groups '((:deadline (after "2017-07-10"))))))
 
+(ert-deftest org-super-agenda-test--:deadline-after-relative ()
+  ;; NOTE: is safe for parallel testing?
+   (advice-add 'org-read-date-get-relative :around #'org-read-date-get-relative-hack)
+   (should (org-super-agenda-test--run
+            :groups '((:deadline (after "+5d")))))
+   (advice-remove 'org-read-date-get-relative #'org-read-date-get-relative-hack))
+
+(ert-deftest org-super-agenda-test--:deadline-before-relative ()
+  ;; NOTE: is safe for parallel testing?
+   (advice-add 'org-read-date-get-relative :around #'org-read-date-get-relative-hack)
+   (should (org-super-agenda-test--run
+            :groups '((:deadline (before "+5d")))))
+   (advice-remove 'org-read-date-get-relative #'org-read-date-get-relative-hack))
+
 (ert-deftest org-super-agenda-test--:effort< ()
   ;; DONE: Works.
   (should (org-super-agenda-test--run
            :groups '((:effort< "5")))))
+
 (ert-deftest org-super-agenda-test--:effort> ()
   ;; DONE: Works.
   (should (org-super-agenda-test--run