bug#17797: 24.3; Include ert-buffer.el in Emacs

bug#17797: 24.3; Include ert-buffer.el in Emacs

[Thorsten Jolitz]

The library 'ert-buffer.el', which does not seem to have a repository
nor to be included in any package repo, but can easily be found via a
web-search, offers some fundamental extensions to ERT functionality in
Emacs core and should thus be included in core.

In summary, it allows to create ert-Buf objects either from string or
from an existing buffer and run tests comparing:

 - point
 - mark
 - content
 - return-value

Since the buffer is such a core concept of Emacs, comparing buffers
seems like a core task in testing. Library ert-buffer.el implements all
the necessary functionality, so that creating this kind of tests is
really fast, even when (sometimes big and complex) real-world
files/buffers are used for testing.

The functionality of ert-buffer.el might potentially be re-implemented
many times when ERT tests that compare buffers are written. Its choice
of criteria for comparing buffers seems pragmatic, keepings things
simple, and thus making it easy to write buffer-tests.

-- 
cheers,
Thorsten

bug#17797: 24.3; Include ert-buffer.el in Emacs

[Stefan Monnier]

> The library 'ert-buffer.el', which does not seem to have a repository
> nor to be included in any package repo, but can easily be found via a
> web-search, offers some fundamental extensions to ERT functionality in
> Emacs core and should thus be included in core.

I don't have a strong opinion either way because I don't know this area
well enough to judge how useful this can be.  So whoever thinks this is
a good or a bad idea, please chime in,


        Stefan

bug#17797: 24.3; Include ert-buffer.el in Emacs

[Stefan Kangas]

Stefan Monnier <monnier@iro.umontreal.ca> writes:

>> The library 'ert-buffer.el', which does not seem to have a repository
>> nor to be included in any package repo, but can easily be found via a
>> web-search, offers some fundamental extensions to ERT functionality in
>> Emacs core and should thus be included in core.
>
> I don't have a strong opinion either way because I don't know this area
> well enough to judge how useful this can be.  So whoever thinks this is
> a good or a bad idea, please chime in,

This seems to be:

https://docutils.sourceforge.io/tools/editors/emacs/tests/ert-buffer.el

I'm not sure that this is useful for general use.  It has some
interesting ideas, but I'm not a big fan of the forms you seem to end up
with:

;;   (should (ert-equal-buffer '(insert "foo")
;;                             ; Insertion of "foo"...
;;   			       (concat ert-Buf-point-char ert-Buf-mark-char)
;;                             ; ...into an empty buffer with point and mark...
;;   			       (concat ert-Buf-mark-char "foo"
;;   				       ert-Buf-point-char)))
;;                             ; ...should result in a buffer containing "foo"
;;                             ; with point and mark moved appropriately.

bug#17797: 24.3; Include ert-buffer.el in Emacs

[Stefan Kangas]

tags 17797 wontfix
close 17797
thanks

Stefan Kangas <stefan@marxist.se> writes:

> Stefan Monnier <monnier@iro.umontreal.ca> writes:
>
>>> The library 'ert-buffer.el', which does not seem to have a repository
>>> nor to be included in any package repo, but can easily be found via a
>>> web-search, offers some fundamental extensions to ERT functionality in
>>> Emacs core and should thus be included in core.
>>
>> I don't have a strong opinion either way because I don't know this area
>> well enough to judge how useful this can be.  So whoever thinks this is
>> a good or a bad idea, please chime in,
>
> This seems to be:
>
> https://docutils.sourceforge.io/tools/editors/emacs/tests/ert-buffer.el
>
> I'm not sure that this is useful for general use.  It has some
> interesting ideas, but I'm not a big fan of the forms you seem to end up
> with:
>
> ;;   (should (ert-equal-buffer '(insert "foo")
> ;;                             ; Insertion of "foo"...
> ;;   			       (concat ert-Buf-point-char ert-Buf-mark-char)
> ;;                             ; ...into an empty buffer with point and mark...
> ;;   			       (concat ert-Buf-mark-char "foo"
> ;;   				       ert-Buf-point-char)))
> ;;                             ; ...should result in a buffer containing "foo"
> ;;                             ; with point and mark moved appropriately.

No further comments within 6 weeks, so I'm closing this as wontfix.