Re: [PATCH v1 1/1] dir: teach status to show ignored directories

On Thu, Aug 10, 2017 at 11:49 AM, Jameson Miller
[off-list ref] wrote:

Welcome to the Git mailing list. :)

Teach Git to optionally show ignored directories when showing all
untracked files. The git status command exposes the options to report
ignored and/or untracked files. However, when reporting all untracked
files (--untracked-files=all), all individual ignored files are reported
as well. It is not currently possible to get the reporting behavior of
the --ignored flag, while also reporting all untracked files.

Trying to understand this based off the documentation for
--untracked=all and --ignored, I realize that the documentation
for --ignored seems to be lacking as I do not understand what the
--ignored behavior is in combination with --untracked=[all, normal, no]

This
change exposes a flag to report all untracked files while not showing
individual files in ignored directories.

By the description up to here, it sounds as if you want to introduce
mode for --untracked, e.g. "normal-adjusted-for-ignored" (it's a bad
suggestion)? However the patch seems to add an orthogonal flag,
such that

  status --no-ignored --untracked=no --show-ignored-directory

would also be possible. What is a reasonable expectation for
the output of such?

Motivation:
Our application (Visual Studio) needs all untracked files listed
individually, but does not need all ignored files listed individually.

For parsing output, I would strongly recommend --porcelain[=2],
but that is a tangent.

Reporting all ignored files can affect the time it takes for status
to run. For a representative repository, here are some measurements
showing a large perf improvement for this scenario:

| Command | Reported ignored entries | Time (s) |
| ------- | ------------------------ | -------- |
| 1       | 0                        | 1.3      |
| 2       | 1024                     | 4.2      |
| 3       | 174904                   | 7.5      |
| 4       | 1046                     | 1.6      |

Commands:
 1) status
 2) status --ignored
 3) status --ignored --untracked-files=all
 4) status --ignored --untracked-files=all --show-ignored-directory

(2) is --untracked-files=normal I'd presume, such that this flag
can be understood as a tweak to "normal" based on the similar size
between 2 and 4? (The timing improvement from 2 to 4 is huge though).

This changes exposes a --show-ignored-directory flag to the git status

s/changes/change/

command. This flag is utilized when running git status with the
--ignored and --untracked-files options to not list ignored individual
ignored files contained in directories that match an ignore pattern.

Part of the perf improvement comes from the tweak to
read_directory_recursive to stop scanning the file system after it
encounters the first file. When a directory is ignored, all it needs to
determine is if the directory is empty or not. The logic currently keeps
scanning the file system until it finds an untracked file. However, as
the directory is ignored, all the contained contents are also marked
excluded. For ignored directories that contain a large number of files,
this can take some time.

I think it is possible to ignore a directory and still track files in it, what
are the implications of this flag on a tracked (and changed) file in an
ignored dir?

What happens to empty directories that match an ignore pattern?

Is it possible to directly read into  s.show_ignored_directory here?

+test_expect_success 'Verify behavior of status on folders with ignored files' '
+       test_when_finished "git clean -fdx" &&
+       git status --porcelain=v2 --ignored --untracked-files=all --show-ignored-directory >output &&
+       test_i18ncmp expect output
+'
+
+# Test status bahavior on folder with tracked and ignored files

behavior

+cat >expect <<\EOF
+? expect
+? output
+! dir/tracked_ignored/ignored_1.ign
+! dir/tracked_ignored/ignored_2.ign
+! tracked_ignored/ignored_1.ign
+! tracked_ignored/ignored_2.ign
+EOF

I think our latest 'best style' is to include these heredocs into the test.