Re: [PATCH v5] ls-files: introduce "--format" option

>
>
> On Tue, Jul 05 2022, ZheNing Hu via GitGitGadget wrote:
>
> > From: ZheNing Hu <adlternative@gmail.com>
> >
> > Add a new option --format that output index enties
> > informations with custom format, taking inspiration
> > from the option with the same name in the `git ls-tree`
> > command.
> >
> > --format cannot used with -s, -o, -k, -t, --resolve-undo,
> > --deduplicate and --eol.
> >
> > Signed-off-by: ZheNing Hu <adlternative@gmail.com>
> > ---
> >     ls-files: introduce "--format" options
> >
> >     v4->v5:
> >
> >      1. Let --format incompatible with -t.
> >      2. Fix %(eolinfo) and %(eolattr) docs suggested by Junio.
> >
> >     Looking forward to Ævar's reviewing.
>
> Thanks again, I took a look at this and it looks good to me as-is.
>
> If you do want to further twiddle with it at this point I applied these
> changes to it locally while poking around, changes:
>
>  * Some trivial whitespace between variable decl.
>
>  * Removed a "return;" at the end of a function
>
>  * I found the new write_*() helpers to be uneccesary, what I did spot
>    after seeing if they could be factored out is the existing
>    write_eolinfo() function.
>
>    I see you just copied some of the code from there, but
>    e.g. initializing to "" and doing an unconditional strbuf_addstr()
>    looks odd IMO compared to just doing it inline as below.
>

>    I think if helpers are to be introduced here I'd think it would make
>    more sense to split out the small bits of behavior from
>    write_eolinfo() so you can call it picemeal and share the code, but
>    since it's calling trivial external functions I think just calling
>    those directly probably makes more sense...
>
>  * Likewise for the test I wondered if you were adding a bug by not
>    reporting when lstat() failed, but then found that this is the same
>    thing we do on --eol.
>

>    So for the tests I think it's better just to demonstrate that we can
>    emit the exact same thing that --eol does with --format.
>
>  * We've gone back & forth a bit on whether this would combine with
>    --debug, while it's an internal-only feature it would be nice to have a
>    test for it combined with --format, noting that the behavior might
>    change...
>

>  * There is one subtle behavior change here in that I deleted the "ce
>    &&" part from write_index_eolinfo_to_buf() when moving the code
>    over. I'm 99% sure this is the right thing to do, as other code in
>    expand_show_index() unconditionally dereferences it.
>
>    So perhaps we don't need that guard in write_eolinfo() either? In any
>    case copy/pasting it over when we're already assuming a non-NULL "ce"
>    in the same "if/elseif/else" chain looks a bit odd.
>
>    Ah, I see it's because in show_dir_entry() we explicitly pass it as
>    NULL, but that doesn't apply to our new codepath, so as long as we're
>    not sharing that helper with write_eolinfo() it makes sense to not do
>    that check.
>

>    Even then the helper should probably assume "ce", and write_eolinfo()
>    itself should do the "is ce NULL?" check which is specific to its
>    use-case.
>
> diff --git a/builtin/ls-files.c b/builtin/ls-files.c
> index 79ecdce2c9c..cc3cece3830 100644
> --- a/builtin/ls-files.c
> +++ b/builtin/ls-files.c
> @@ -77,30 +77,6 @@ static void write_eolinfo(struct index_state *istate,
>         }
>  }
>
> -static void write_index_eolinfo_to_buf(struct strbuf *sb, struct index_state *istate,
> -                                      const struct cache_entry *ce)
> -{
> -       const char *i_txt = "";
> -       if (ce && S_ISREG(ce->ce_mode))
> -               i_txt = get_cached_convert_stats_ascii(istate, ce->name);
> -       strbuf_addstr(sb, i_txt);
> -}
> -
> -static void write_worktree_eolinfo_to_buf(struct strbuf *sb, const char *path)
> -{
> -       struct stat st;
> -       const char *w_txt = "";
> -       if (!lstat(path, &st) && S_ISREG(st.st_mode))
> -               w_txt = get_wt_convert_stats_ascii(path);
> -       strbuf_addstr(sb, w_txt);
> -}
> -
> -static void write_eolattr_to_buf(struct strbuf *sb, struct index_state *istate,
> -                                const char *path)
> -{
> -       strbuf_addstr(sb, get_convert_attr_ascii(istate, path));
> -}
> -
>  static void write_name(const char *name)
>  {
>         /*
> @@ -114,6 +90,7 @@ static void write_name(const char *name)
>  static void write_name_to_buf(struct strbuf *sb, const char *name)
>  {
>         const char *rel = relative_path(name, prefix_len ? prefix : NULL, sb);
> +
>         if (line_terminator)
>                 quote_c_style(rel, sb, NULL, 0);
>         else
> @@ -270,6 +247,8 @@ static size_t expand_show_index(struct strbuf *sb, const char *start,
>         const char *end;
>         const char *p;
>         size_t len = strbuf_expand_literal_cb(sb, start, NULL);
> +       struct stat st;
> +
>         if (len)
>                 return len;
>         if (*start != '(')
> @@ -288,12 +267,16 @@ static size_t expand_show_index(struct strbuf *sb, const char *start,
>                 strbuf_add_unique_abbrev(sb, &data->ce->oid, abbrev);
>         else if (skip_prefix(start, "(stage)", &p))
>                 strbuf_addf(sb, "%d", ce_stage(data->ce));
> -       else if (skip_prefix(start, "(eolinfo:index)", &p))
> -               write_index_eolinfo_to_buf(sb, data->istate, data->ce);
> -       else if (skip_prefix(start, "(eolinfo:worktree)", &p))
> -               write_worktree_eolinfo_to_buf(sb, data->pathname);
> +       else if (skip_prefix(start, "(eolinfo:index)", &p) &&
> +                S_ISREG(data->ce->ce_mode))
> +               strbuf_addstr(sb, get_cached_convert_stats_ascii(data->istate,
> +                                                                data->ce->name));
> +       else if (skip_prefix(start, "(eolinfo:worktree)", &p) &&
> +                !lstat(data->pathname, &st) && S_ISREG(st.st_mode))
> +               strbuf_addstr(sb, get_wt_convert_stats_ascii(data->pathname));
>         else if (skip_prefix(start, "(eolattr)", &p))
> -               write_eolattr_to_buf(sb, data->istate, data->pathname);
> +               strbuf_addstr(sb, get_convert_attr_ascii(data->istate,
> +                                                        data->pathname));
>         else if (skip_prefix(start, "(path)", &p))
>                 write_name_to_buf(sb, data->pathname);
>         else
> @@ -310,13 +293,12 @@ static void show_ce_fmt(struct repository *repo, const struct cache_entry *ce,
>                 .istate = repo->index,
>                 .ce = ce,
>         };
> -
>         struct strbuf sb = STRBUF_INIT;
> +
>         strbuf_expand(&sb, format, expand_show_index, &data);
>         strbuf_addch(&sb, line_terminator);
>         fwrite(sb.buf, sb.len, 1, stdout);
>         strbuf_release(&sb);
> -       return;
>  }
>
>  static void show_ce(struct repository *repo, struct dir_struct *dir,
> diff --git a/t/t3013-ls-files-format.sh b/t/t3013-ls-files-format.sh
> index 60c415aafd6..baf03f9096e 100755
> --- a/t/t3013-ls-files-format.sh
> +++ b/t/t3013-ls-files-format.sh
> @@ -40,27 +40,13 @@ test_expect_success 'git ls-files --format objectname' '
>         test_cmp expect actual
>  '
>
> -test_expect_success 'git ls-files --format eolinfo:index' '
> -       cat >expect <<-\EOF &&
> -       lf
> -       lf
> -       EOF
> -       git ls-files --format="%(eolinfo:index)" >actual &&
> -       test_cmp expect actual
> -'
> -
> -test_expect_success 'git ls-files --format eolinfo:worktree' '
> -       cat >expect <<-\EOF &&
> -       lf
> -       lf
> -       EOF
> -       git ls-files --format="%(eolinfo:worktree)" >actual &&
> -       test_cmp expect actual
> -'
> -
> -test_expect_success 'git ls-files --format eolattr' '
> -       printf "\n\n" >expect &&
> -       git ls-files --format="%(eolattr)" >actual &&
> +HT='   '
> +WS='    '
> +test_expect_success 'git ls-files --format v.s. --eol' '
> +       git ls-files --eol >expect 2>err &&
> +       test_must_be_empty err &&
> +       git ls-files --format="i/%(eolinfo:index)${WS}w/%(eolinfo:worktree)${WS}attr/${WS}${WS}${WS}${WS} ${HT}%(path)" >actual 2>err &&
> +       test_must_be_empty err &&
>         test_cmp expect actual
>  '
>