FYI: with-org-today-date macro, helps with testing

FYI: with-org-today-date macro, helps with testing

[Adam Porter]

Hi friends,

Just wanted to drop this here.  I was testing some agenda-related code,
and got tired of having to keep moving the dates forward on my test data
as days passed in real life, so after digging into the agenda code, I
came up with this macro that makes testing much easier:

#+BEGIN_SRC elisp
  (defmacro with-org-today-date (date &rest body)
    "Run BODY with the `org-today' function set to return simply DATE.
  DATE should be a date-time string (both date and time must be included)."
    (declare (indent defun))
    `(let ((day (date-to-day ,date))
           (orig (symbol-function 'org-today)))
       (unwind-protect
           (progn
             (fset 'org-today (lambda () day))
             ,@body)
         (fset 'org-today orig))))
#+END_SRC

You can use it like this:

#+BEGIN_SRC elisp
  (with-org-today-date "2017-07-05 00:00"
    (let ((org-agenda-files (list "~/test.org"))
          (org-agenda-span 'day))
      (org-agenda-list nil)))
#+END_SRC

Hope someone finds this useful.

Re: FYI: with-org-today-date macro, helps with testing

[Kyle Meyer]

Adam Porter <adam@alphapapa.net> writes:

> #+BEGIN_SRC elisp
>   (defmacro with-org-today-date (date &rest body)
>     "Run BODY with the `org-today' function set to return simply DATE.
>   DATE should be a date-time string (both date and time must be included)."
>     (declare (indent defun))
>     `(let ((day (date-to-day ,date))
>            (orig (symbol-function 'org-today)))
>        (unwind-protect
>            (progn
>              (fset 'org-today (lambda () day))
>              ,@body)
>          (fset 'org-today orig))))
> #+END_SRC

You should be able to simplify the macro body to

    `(cl-letf (((symbol-function 'org-today) (lambda () (date-to-day ,date))))
       ,@body)
-- 
Kyle

Re: FYI: with-org-today-date macro, helps with testing

[Adam Porter]

Kyle Meyer <kyle@kyleam.com> writes:

> Adam Porter <adam@alphapapa.net> writes:
>
>> #+BEGIN_SRC elisp
>>   (defmacro with-org-today-date (date &rest body)
>>     "Run BODY with the `org-today' function set to return simply DATE.
>>   DATE should be a date-time string (both date and time must be included)."
>>     (declare (indent defun))
>>     `(let ((day (date-to-day ,date))
>>            (orig (symbol-function 'org-today)))
>>        (unwind-protect
>>            (progn
>>              (fset 'org-today (lambda () day))
>>              ,@body)
>>          (fset 'org-today orig))))
>> #+END_SRC
>
> You should be able to simplify the macro body to
>
>     `(cl-letf (((symbol-function 'org-today) (lambda () (date-to-day ,date))))
>        ,@body)

Hi Kyle,

I tried that, but it didn't work, so I had to come up with this uglier
one.  I couldn't figure out why, but with cl-letf, the redefined
function didn't seem to persist deeper in the tree of function calls,
only to the first level.  Maybe I did something wrong, but all I know
now is that at least this works.  :)

Thanks.

Re: FYI: with-org-today-date macro, helps with testing

[Kyle Meyer]

Adam Porter <adam@alphapapa.net> writes:

> Kyle Meyer <kyle@kyleam.com> writes:

[...]

>> You should be able to simplify the macro body to
>>
>>     `(cl-letf (((symbol-function 'org-today) (lambda () (date-to-day ,date))))
>>        ,@body)
>
> Hi Kyle,
>
> I tried that, but it didn't work, so I had to come up with this uglier
> one.  I couldn't figure out why, but with cl-letf, the redefined
> function didn't seem to persist deeper in the tree of function calls,
> only to the first level.  Maybe I did something wrong, but all I know
> now is that at least this works.  :)

On my end,

  (defmacro with-org-today-date (date &rest body)
    `(cl-letf (((symbol-function 'org-today) (lambda () (date-to-day ,date))))
       ,@body))
  
  (with-org-today-date "2017-07-05 00:00"
    (let ((org-agenda-files (list "~/test.org"))
          (org-agenda-span 'day))
      (org-agenda-list nil)))

produces the same result as your original macro.

-- 
Kyle

Re: FYI: with-org-today-date macro, helps with testing

[Adam Porter]

Thanks, maybe I was up too late to be messing with macros.  :)

Re: FYI: with-org-today-date macro, helps with testing

[Samuel Wales]

i duly saved this macro, didn't think to look for it, and used datefudge(1).