Re: [PATCH] advice: refactor advise API

>
> On 2/10/2020 12:04 AM, Heba Waly via GitGitGadget wrote:
> > From: Heba Waly <heba.waly@gmail.com>
> >
> > Add a new advise_ng function that can check the visibility of advice
> > messages before printing.
> >
> > Currently it's very easy for the callers to miss checking the
> > visibility step. Also, it makes more sense for this step to be handled
> > by the advice library.
>
> This makes the advice API much easier and its uses much cleaner. Thanks!
>
> > Also change the advise call in tag library from advise() to advise_ng()
> > to construct an example of the usage of the new API.
>
> This is a good example case.
>
> > +static const char turn_off_instructions[] =
> > +N_("\n"
> > +"Turn this message off by running\n"
> > +"\"git config %s false\"");
>
> I have mixed feelings on the use of these instructions. Perhaps at
> minimum the addition of these instructions could be left to a
> separate patch than the creation of advise_ng().
>
> My biggest concern is that this adds unexpected noise to users who
> want the advice to stay. I'm calling attention to it, because this
> part isn't a simple refactor like the rest of the patch.
>
> If it _does_ stay, then I recommend condensing the message to
> a single line. For example:
>
>         Disable this message with "git config %d false"
>

> > +     if(value)
> > +     {
>
> Style: spacing, and opening braces are on the same line as the if:
>
>         if (value) {
>
> But also, this method would be simpler if the opposite case was
> an early return:
>
>         if (!value)
>                 return;
> Then the rest could have one less indentation.

> This loop looks like it was copied from advise(). Perhaps we could
> re-use that code better by creating a new vadvise() method that
> takes a va_list, and have advise() and advise_ng() call it instead?
> I include a patch at the end of this method that does this conversion.
> (Feel free to incorporate it into your next version, if you want, but
> be sure to add your sign-off.) Then, your advise_ng() can call these:
>
>         vadvise(advice, params);
>         advise(turn_off_instructions, key);
>
> removing the need to re-implement the for loop.

> > diff --git a/t/helper/test-advise.c b/t/helper/test-advise.c
> > new file mode 100644
> > index 0000000000..b6ec90fd18
> > --- /dev/null
> > +++ b/t/helper/test-advise.c
> > @@ -0,0 +1,15 @@
> > +#include "test-tool.h"
> > +#include "cache.h"
> > +#include "advice.h"
> > +
> > +int cmd__advise_ng(int argc, const char **argv)
> > +{
> > +     if (!argv[1] || !argv[2])
> > +     die("usage: %s <key> <advice>", argv[0]);
> > +
> > +     setup_git_directory();
> > +
> > +     advise_ng(argv[1], argv[2]);
> > +
> > +     return 0;
> > +}
>
> I definitely tend to recommend more tests than most, but perhaps this
> unit test is overkill? You demonstrate a good test below using a real
> Git command, which should be sufficient. If the "turn this message off"
> part gets removed, then you will still have coverage of your method.
> It just won't require a test change because it would not modify behavior.
>

> > diff --git a/t/t7004-tag.sh b/t/t7004-tag.sh
> > index 6db92bd3ba..b7c8d41899 100755
> > --- a/t/t7004-tag.sh
> > +++ b/t/t7004-tag.sh
> > @@ -1726,6 +1726,8 @@ test_expect_success 'recursive tagging should give advice' '
> >       hint: already a tag. If you meant to tag the object that it points to, use:
> >       hint: |
> >       hint:   git tag -f nested annotated-v4.0^{}
> > +     hint: Turn this message off by running
> > +     hint: "git config advice.nestedTag false"
> >       EOF
> >       git tag -m nested nested annotated-v4.0 2>actual &&
> >       test_i18ncmp expect actual
> >
> > base-commit: c7a62075917b3340f908093f63f1161c44ed1475
>
> Thanks,
> -Stolee
>
> -->8--
>
> From: Derrick Stolee <dstolee@microsoft.com>
> Date: Mon, 10 Feb 2020 09:33:20 -0500
> Subject: [PATCH] advice: extract vadvise() from advise()
>
> In preparation for a new advice method, extract a version of advise()
> that uses an explict 'va_list' parameter. Call it from advise() for a
> functionally equivalent version.
>
> Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
> ---
>  advice.c | 13 +++++++++----
>  1 file changed, 9 insertions(+), 4 deletions(-)
>
> diff --git a/advice.c b/advice.c
> index 249c60dcf3..fd836332da 100644
> --- a/advice.c
> +++ b/advice.c
> @@ -96,15 +96,12 @@ static struct {
>         { "pushNonFastForward", &advice_push_update_rejected }
>  };
>
> -void advise(const char *advice, ...)
> +static void vadvise(const char *advice, va_list params)
>  {
>         struct strbuf buf = STRBUF_INIT;
> -       va_list params;
>         const char *cp, *np;
>
> -       va_start(params, advice);
>         strbuf_vaddf(&buf, advice, params);
> -       va_end(params);
>
>         for (cp = buf.buf; *cp; cp = np) {
>                 np = strchrnul(cp, '\n');
> @@ -118,6 +115,14 @@ void advise(const char *advice, ...)
>         strbuf_release(&buf);
>  }
>
> +void advise(const char *advice, ...)
> +{
> +       va_list params;
> +       va_start(params, advice);
> +       vadvise(advice, params);
> +       va_end(params);
> +}
> +
>  int git_default_advice_config(const char *var, const char *value)
>  {
>         const char *k, *slot_name;
> --
> 2.25.0.vfs.1.1.1.g9906319d24.dirty
>
>
>