* bug#35018: 26.1; Use diff as en ert-explainer for string=
@ 2019-03-27 10:19 Pierre Neidhardt
2019-04-02 1:05 ` Noam Postavsky
2021-06-23 13:42 ` Lars Ingebrigtsen
0 siblings, 2 replies; 10+ messages in thread
From: Pierre Neidhardt @ 2019-03-27 10:19 UTC (permalink / raw)
To: 35018
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I've just committed webfeeder.el to ELPA. In his review, Stefan Monnier
suggested we merged the following code snippet upstream:
--8<---------------cut here---------------start------------->8---
(defun webfeeder--string=-explainer (string-a string-b)
"Return the diff output of STRING-A and STRING-B"
(unless (string= string-a string-b)
(let (file-a file-b)
(unwind-protect
(let (result)
(setq file-a (make-temp-file "webfeeder")
file-b (make-temp-file "webfeeder"))
(with-temp-file file-a
(insert string-a))
(with-temp-file file-b
(insert string-b))
(setq result
(with-temp-buffer
;; The following generates a *Diff* buffer which is
;; convenient for coloration.
(diff file-a file-b nil 'no-async)
(diff-no-select file-a file-b nil 'no-async (current-buffer))
(buffer-string)))
result)
(delete-file file-a)
(delete-file file-b)))))
;; FIXME: Add this to ERT!
(put 'string= 'ert-explainer #'webfeeder--string=-explainer)
--8<---------------cut here---------------end--------------->8---
I've used this feature extensively in my ERT tests: it displays a "diff"
of string A and string B, which is a pretty nice default when the
strings are longer than a single line.
Food for thoughts :)
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--
Pierre Neidhardt
https://ambrevar.xyz/
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^ permalink raw reply [flat|nested] 10+ messages in thread* bug#35018: 26.1; Use diff as en ert-explainer for string=
2019-03-27 10:19 bug#35018: 26.1; Use diff as en ert-explainer for string= Pierre Neidhardt
@ 2019-04-02 1:05 ` Noam Postavsky
2019-04-02 7:59 ` Pierre Neidhardt
2021-06-23 13:42 ` Lars Ingebrigtsen
1 sibling, 1 reply; 10+ messages in thread
From: Noam Postavsky @ 2019-04-02 1:05 UTC (permalink / raw)
To: Pierre Neidhardt; +Cc: 35018
severity 35018 wishlist
quit
Pierre Neidhardt <mail@ambrevar.xyz> writes:
> I've just committed webfeeder.el to ELPA. In his review, Stefan Monnier
> suggested we merged the following code snippet upstream:
>
> (defun webfeeder--string=-explainer (string-a string-b)
> "Return the diff output of STRING-A and STRING-B"
> (unless (string= string-a string-b)
I guess a diff won't help so much for single line strings, so maybe the
condition should check for that? e.g.
(or (string= string-a string-b)
(not (string-match-p "\n" string-a))
(not (string-match-p "\n" string-b))
> (let (file-a file-b)
> (unwind-protect
> (let (result)
> (setq file-a (make-temp-file "webfeeder")
> file-b (make-temp-file "webfeeder"))
> (with-temp-file file-a
> (insert string-a))
> (with-temp-file file-b
> (insert string-b))
> (setq result
> (with-temp-buffer
> ;; The following generates a *Diff* buffer which is
> ;; convenient for coloration.
> (diff file-a file-b nil 'no-async)
> (diff-no-select file-a file-b nil 'no-async (current-buffer))
Isn't the diff-no-select redudant, since diff already calls it?
> (buffer-string)))
> result)
You don't need the 'result' variable here, just make the
(with-temp-buffer...) the last expression in the let (which could then
be converted to progn).
> (delete-file file-a)
> (delete-file file-b)))))
You should check that each of file-a and file-b are non-nil before
trying to delete (in case either make-temp-file signals an error).
^ permalink raw reply [flat|nested] 10+ messages in thread* bug#35018: 26.1; Use diff as en ert-explainer for string=
2019-04-02 1:05 ` Noam Postavsky
@ 2019-04-02 7:59 ` Pierre Neidhardt
0 siblings, 0 replies; 10+ messages in thread
From: Pierre Neidhardt @ 2019-04-02 7:59 UTC (permalink / raw)
To: Noam Postavsky; +Cc: 35018
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Thanks for the review!
Noam Postavsky <npostavs@gmail.com> writes:
>> (defun webfeeder--string=-explainer (string-a string-b)
>> "Return the diff output of STRING-A and STRING-B"
>> (unless (string= string-a string-b)
>
> I guess a diff won't help so much for single line strings, so maybe the
> condition should check for that? e.g.
>
> (or (string= string-a string-b)
> (not (string-match-p "\n" string-a))
> (not (string-match-p "\n" string-b))
Yes, this is very nice!
>> (let (file-a file-b)
>> (unwind-protect
>> (let (result)
>> (setq file-a (make-temp-file "webfeeder")
>> file-b (make-temp-file "webfeeder"))
>> (with-temp-file file-a
>> (insert string-a))
>> (with-temp-file file-b
>> (insert string-b))
>> (setq result
>> (with-temp-buffer
>> ;; The following generates a *Diff* buffer which is
>> ;; convenient for coloration.
>> (diff file-a file-b nil 'no-async)
>> (diff-no-select file-a file-b nil 'no-async (current-buffer))
>
> Isn't the diff-no-select redudant, since diff already calls it?
The first diff is a typo. It should be diff-no-select only.
Cheers!
--
Pierre Neidhardt
https://ambrevar.xyz/
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^ permalink raw reply [flat|nested] 10+ messages in thread
* bug#35018: 26.1; Use diff as en ert-explainer for string=
2019-03-27 10:19 bug#35018: 26.1; Use diff as en ert-explainer for string= Pierre Neidhardt
2019-04-02 1:05 ` Noam Postavsky
@ 2021-06-23 13:42 ` Lars Ingebrigtsen
2021-06-24 7:06 ` Pierre Neidhardt
1 sibling, 1 reply; 10+ messages in thread
From: Lars Ingebrigtsen @ 2021-06-23 13:42 UTC (permalink / raw)
To: Pierre Neidhardt; +Cc: 35018, Stefan Monnier
Pierre Neidhardt <mail@ambrevar.xyz> writes:
> I've just committed webfeeder.el to ELPA. In his review, Stefan Monnier
> suggested we merged the following code snippet upstream:
I've adapted this to ert to see how it would look, and... I'm not sure
it's all that helpful as is. The following test:
(ert-deftest test-test-test ()
(should (string= "foo\nbar" "zot\nbar")))
then gives this output:
(ert-test-failed
((should
(string= "foo\12bar" "zot\12bar"))
:form
(string= "foo\12bar" "zot\12bar")
:value nil :explanation "diff -u /tmp/webfeeder1kS4io /tmp/webfeederwYoKdx\12--- /tmp/webfeeder1kS4io\0112021-06-23 15:37:54.407053381 +0200\12+++ /tmp/webfeederwYoKdx\0112021-06-23 15:37:54.407053381 +0200\12@@ -1,2 +1,2 @@\12-foo\12+zot\12 bar\12\\ No newline at end of file\12\12Diff finished. Wed Jun 23 15:37:54 2021\12"))
Which isn't all that nice.
But I guess we could massage the output. Removing the header and
trailer, we get:
(ert-test-failed
((should
(string= "foo\12bar" "zot\12bar"))
:form
(string= "foo\12bar" "zot\12bar")
:value nil :explanation "@@ -1,2 +1,2 @@\12-foo\12+zot\12 bar\12\\ "))
But... that's still not exactly readable.
So I don't know. Anybody got an opinion here, or an easy fix that'll
make this readable in this context?
diff --git a/lisp/emacs-lisp/ert.el b/lisp/emacs-lisp/ert.el
index 6793b374ee..004bc81b4a 100644
--- a/lisp/emacs-lisp/ert.el
+++ b/lisp/emacs-lisp/ert.el
@@ -63,6 +63,7 @@
(require 'ewoc)
(require 'find-func)
(require 'pp)
+(require 'diff)
;;; UI customization options.
@@ -535,6 +536,34 @@ ert--explain-equal
(ert--explain-equal-rec a b)))
(put 'equal 'ert-explainer 'ert--explain-equal)
+(defun ert--explain-string (string-a string-b)
+ "Return the diff output of STRING-A and STRING-B"
+ (unless (or (string= string-a string-b)
+ ;; Only do diffs if there are newlines.
+ (not (string-match-p "\n" string-a))
+ (not (string-match-p "\n" string-b)))
+ (let (file-a file-b)
+ (unwind-protect
+ (let (result)
+ (setq file-a (make-temp-file "ert")
+ file-b (make-temp-file "ert"))
+ (with-temp-file file-a
+ (insert string-a))
+ (with-temp-file file-b
+ (insert string-b))
+ (setq result
+ (with-temp-buffer
+ ;; The following generates a *Diff* buffer which is
+ ;; convenient for coloration.
+ (diff-no-select file-a file-b nil 'no-async)
+ (diff-no-select file-a file-b nil 'no-async
+ (current-buffer))
+ (buffer-string)))
+ result)
+ (delete-file file-a)
+ (delete-file file-b)))))
+(put 'string= 'ert-explainer #'ert--explain-string)
+
(defun ert--significant-plist-keys (plist)
"Return the keys of PLIST that have non-null values, in order."
(cl-assert (zerop (mod (length plist) 2)) t)
--
(domestic pets only, the antidote for overdose, milk.)
bloggy blog: http://lars.ingebrigtsen.no
^ permalink raw reply related [flat|nested] 10+ messages in thread
end of thread, other threads:[~2021-10-13 11:21 UTC | newest]
Thread overview: 10+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2019-03-27 10:19 bug#35018: 26.1; Use diff as en ert-explainer for string= Pierre Neidhardt
2019-04-02 1:05 ` Noam Postavsky
2019-04-02 7:59 ` Pierre Neidhardt
2021-06-23 13:42 ` Lars Ingebrigtsen
2021-06-24 7:06 ` Pierre Neidhardt
2021-06-24 14:52 ` Lars Ingebrigtsen
2021-06-24 15:59 ` Pierre Neidhardt
2021-10-12 15:33 ` Lars Ingebrigtsen
2021-10-12 17:23 ` Pierre Neidhardt
2021-10-13 11:21 ` Lars Ingebrigtsen
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