diff mbox series

[v5,2/2] difftool.c: learn a new way start at specified file

Message ID 98e2707ee2faf653e972b0706311ddd099765ce5.1613480198.git.gitgitgadget@gmail.com (mailing list archive)
State New, archived
Headers show
Series difftool.c: learn a new way start at specified file | expand

Commit Message

ZheNing Hu Feb. 16, 2021, 12:56 p.m. UTC 
From: ZheNing Hu <adlternative@gmail.com>

`git difftool` only allow us to select file to view in turn.
If there is a commit with many files and we exit in the search,
We will have to traverse list again to get the file diff which
we want to see. Therefore, here is a new method: user can use
`git difftool --rotate-to=<filename>` or `git difftool --skip-to=<filename>`
to start viewing from the specified file, This will improve the
user experience.

`git difftool --rotate-to=<file>` or `git difftool --skip-to=<filename>`
will pass the path to `diffcore-rotate`, and diff-core will
adjust the order of files, make the specified file sorted to
the first.`git difftool --rotate-to=<file>` will move files before
the  specified path to the last output, and
`git difftool --skip-to=<filename>`  will ignore these files output.
It is an error when there is no patch for specified file is shown.

Signed-off-by: ZheNing Hu <adlternative@gmail.com>
---
 Documentation/diff-options.txt |  2 +-
 Documentation/git-difftool.txt | 10 ++++++++++
 t/t7800-difftool.sh            | 30 ++++++++++++++++++++++++++++++
 3 files changed, 41 insertions(+), 1 deletion(-)

Comments

Junio C Hamano Feb. 17, 2021, 10:31 a.m. UTC | #1 
"ZheNing Hu via GitGitGadget" <gitgitgadget@gmail.com> writes:

> From: ZheNing Hu <adlternative@gmail.com>
>
> `git difftool` only allow us to select file to view in turn.
> If there is a commit with many files and we exit in the search,

I am not sure what "in the search" refers to.  "in the middle" I
would understand, though.

> We will have to traverse list again to get the file diff which

Let's downcase this "We".

> we want to see. Therefore, here is a new method: user can use
> `git difftool --rotate-to=<filename>` or `git difftool --skip-to=<filename>`
> to start viewing from the specified file, This will improve the
> user experience.

Do we need both?  I'd rather not to give end-user-facing commands
too many knobs that would do similar things.  Too many choices to
choose from without clear answer to "which one should I prefer to
use?" is a bad combination for end-users.

> diff --git a/Documentation/diff-options.txt b/Documentation/diff-options.txt
> index 7c5b3cf42bcc..aa2b5c11f20b 100644
> --- a/Documentation/diff-options.txt
> +++ b/Documentation/diff-options.txt
> @@ -701,7 +701,7 @@ components matches the pattern.  For example, the pattern "`foo*bar`"
>  matches "`fooasdfbar`" and "`foo/bar/baz/asdf`" but not "`foobarx`".
>  
>  --skip-to=<file>::
> ---rotate-to=<file::
> +--rotate-to=<file>::
>  	Discard the files before the named <file> from the output
>  	(i.e. 'skip to'), or move them to the end of the output
>  	(i.e. 'rotate to').  These were invented primarily for use

Thanks for correcting, but this change should not be a part of this
patch.  Instead, you help the other's topic by giving a review (and
you could just have said "there there is closing '>' missing").

> diff --git a/Documentation/git-difftool.txt b/Documentation/git-difftool.txt
> index 484c485fd06c..c64dff69c976 100644
> --- a/Documentation/git-difftool.txt
> +++ b/Documentation/git-difftool.txt
> @@ -34,6 +34,16 @@ OPTIONS
>  	This is the default behaviour; the option is provided to
>  	override any configuration settings.
>  
> +--rotate-to=<file>::
> +	Internally call `git diff --rotate-to=<file>`,
> +	show the change in the specified path first.
> +	Files before the specified path will be moved to the last output.
> +
> +--skip-to=<file>::
> +	Internally call `git diff --skip-to=<file>`,
> +	skip the output to the specified path.
> +	Files before the specified path will not output.
> +

This, unlike the "diffcore" stuff, is end-user facing, and it is
better not to force the readers even know what --skip-to option
to the diff does (after all, difftool users are using 'git difftool'
and they are not necessarily 'git diff' users).

    --skip-to=<file>::
            Start showing the diff for the given path, skipping all
            the paths before it.

or something, perhaps.

> +test_expect_success 'difftool --skip-to' '
> +	difftool_test_setup &&
> +	test_when_finished git reset --hard &&
> +	git difftool --no-prompt --extcmd=cat --skip-to="2" HEAD^ >output &&
> +	cat >expect <<-\EOF &&
> +	2
> +	4
> +	EOF
> +	test_cmp output expect &&
> +	test_must_fail git difftool --no-prompt --extcmd=cat --skip-to="3" HEAD^
> +'

This probably should be split into two independent tests.  One to
check that the non-failing case works as expected, the other to
check that a bogus command line option errors out as expected.

Thanks.
ZheNing Hu Feb. 17, 2021, 4:18 p.m. UTC | #2 
Junio C Hamano <gitster@pobox.com> 于2021年2月17日周三 下午6:31写道：
>
> "ZheNing Hu via GitGitGadget" <gitgitgadget@gmail.com> writes:
>
> > From: ZheNing Hu <adlternative@gmail.com>
> >
> > `git difftool` only allow us to select file to view in turn.
> > If there is a commit with many files and we exit in the search,
>
> I am not sure what "in the search" refers to.  "in the middle" I
> would understand, though.
>
> > We will have to traverse list again to get the file diff which
>
> Let's downcase this "We".
>
> > we want to see. Therefore, here is a new method: user can use
> > `git difftool --rotate-to=<filename>` or `git difftool --skip-to=<filename>`
> > to start viewing from the specified file, This will improve the
> > user experience.
>
> Do we need both?  I'd rather not to give end-user-facing commands
> too many knobs that would do similar things.  Too many choices to
> choose from without clear answer to "which one should I prefer to
> use?" is a bad combination for end-users.
>
So users will not need to use `git difftool --skip-to`? Then I am confused
about the meaning of `git difftool --skip-to`.
> > diff --git a/Documentation/diff-options.txt b/Documentation/diff-options.txt
> > index 7c5b3cf42bcc..aa2b5c11f20b 100644
> > --- a/Documentation/diff-options.txt
> > +++ b/Documentation/diff-options.txt
> > @@ -701,7 +701,7 @@ components matches the pattern.  For example, the pattern "`foo*bar`"
> >  matches "`fooasdfbar`" and "`foo/bar/baz/asdf`" but not "`foobarx`".
> >
> >  --skip-to=<file>::
> > ---rotate-to=<file::
> > +--rotate-to=<file>::
> >       Discard the files before the named <file> from the output
> >       (i.e. 'skip to'), or move them to the end of the output
> >       (i.e. 'rotate to').  These were invented primarily for use
>
> Thanks for correcting, but this change should not be a part of this
> patch.  Instead, you help the other's topic by giving a review (and
> you could just have said "there there is closing '>' missing").
>
Okay, I will pay attention later.
> > diff --git a/Documentation/git-difftool.txt b/Documentation/git-difftool.txt
> > index 484c485fd06c..c64dff69c976 100644
> > --- a/Documentation/git-difftool.txt
> > +++ b/Documentation/git-difftool.txt
> > @@ -34,6 +34,16 @@ OPTIONS
> >       This is the default behaviour; the option is provided to
> >       override any configuration settings.
> >
> > +--rotate-to=<file>::
> > +     Internally call `git diff --rotate-to=<file>`,
> > +     show the change in the specified path first.
> > +     Files before the specified path will be moved to the last output.
> > +
> > +--skip-to=<file>::
> > +     Internally call `git diff --skip-to=<file>`,
> > +     skip the output to the specified path.
> > +     Files before the specified path will not output.
> > +
>
> This, unlike the "diffcore" stuff, is end-user facing, and it is
> better not to force the readers even know what --skip-to option
> to the diff does (after all, difftool users are using 'git difftool'
> and they are not necessarily 'git diff' users).
>
>     --skip-to=<file>::
>             Start showing the diff for the given path, skipping all
>             the paths before it.
>
> or something, perhaps.
>
> > +test_expect_success 'difftool --skip-to' '
> > +     difftool_test_setup &&
> > +     test_when_finished git reset --hard &&
> > +     git difftool --no-prompt --extcmd=cat --skip-to="2" HEAD^ >output &&
> > +     cat >expect <<-\EOF &&
> > +     2
> > +     4
> > +     EOF
> > +     test_cmp output expect &&
> > +     test_must_fail git difftool --no-prompt --extcmd=cat --skip-to="3" HEAD^
> > +'
>
> This probably should be split into two independent tests.  One to
> check that the non-failing case works as expected, the other to
> check that a bogus command line option errors out as expected.
>
I will finish it.
> Thanks.

Besides, I have some curiosity about one place in the code in your
patch:
> int cmd_diff_tree(...)
> ...
> if (read_stdin) {
> ...
> opt->diffopt.rotate_to_strict = 0;
> ...
}
This is the only place where rotate_to_strict is set to zero,
So the "git log -p" you mentioned earlier is here Called this code
to avoid exiting  the program because of the wrong path, right?

Thanks.
diff mbox series

Patch

diff --git a/Documentation/diff-options.txt b/Documentation/diff-options.txt
index 7c5b3cf42bcc..aa2b5c11f20b 100644
--- a/Documentation/diff-options.txt
+++ b/Documentation/diff-options.txt
@@ -701,7 +701,7 @@  components matches the pattern.  For example, the pattern "`foo*bar`"
 matches "`fooasdfbar`" and "`foo/bar/baz/asdf`" but not "`foobarx`".
 
 --skip-to=<file>::
---rotate-to=<file::
+--rotate-to=<file>::
 	Discard the files before the named <file> from the output
 	(i.e. 'skip to'), or move them to the end of the output
 	(i.e. 'rotate to').  These were invented primarily for use
diff --git a/Documentation/git-difftool.txt b/Documentation/git-difftool.txt
index 484c485fd06c..c64dff69c976 100644
--- a/Documentation/git-difftool.txt
+++ b/Documentation/git-difftool.txt
@@ -34,6 +34,16 @@  OPTIONS
 	This is the default behaviour; the option is provided to
 	override any configuration settings.
 
+--rotate-to=<file>::
+	Internally call `git diff --rotate-to=<file>`,
+	show the change in the specified path first.
+	Files before the specified path will be moved to the last output.
+
+--skip-to=<file>::
+	Internally call `git diff --skip-to=<file>`,
+	skip the output to the specified path.
+	Files before the specified path will not output.
+
 -t <tool>::
 --tool=<tool>::
 	Use the diff tool specified by <tool>.  Valid values include
diff --git a/t/t7800-difftool.sh b/t/t7800-difftool.sh
index 9192c141ffc6..112b798b1c23 100755
--- a/t/t7800-difftool.sh
+++ b/t/t7800-difftool.sh
@@ -762,4 +762,34 @@  test_expect_success 'difftool --gui, --tool and --extcmd are mutually exclusive'
 	test_must_fail git difftool --gui --tool=test-tool --extcmd=cat
 '
 
+test_expect_success 'difftool --rotate-to' '
+	difftool_test_setup &&
+	test_when_finished git reset --hard &&
+	echo 1 >1 &&
+	echo 2 >2 &&
+	echo 4 >4 &&
+	git add 1 2 4 &&
+	git commit -a -m "124" &&
+	git difftool --no-prompt --extcmd=cat --rotate-to="2" HEAD^ >output&&
+	cat >expect <<-\EOF &&
+	2
+	4
+	1
+	EOF
+	test_cmp output expect &&
+	test_must_fail git difftool --no-prompt --extcmd=cat --rotate-to="3" HEAD^
+'
+
+test_expect_success 'difftool --skip-to' '
+	difftool_test_setup &&
+	test_when_finished git reset --hard &&
+	git difftool --no-prompt --extcmd=cat --skip-to="2" HEAD^ >output &&
+	cat >expect <<-\EOF &&
+	2
+	4
+	EOF
+	test_cmp output expect &&
+	test_must_fail git difftool --no-prompt --extcmd=cat --skip-to="3" HEAD^
+'
+
 test_done