patchtab completion of filenames for 'git restore'

From: David Cantrell <david@cantrell.org.uk>

If no --args are present after 'git restore' it assumes that you want to tab-complete one of the files with uncommitted changes

Signed-off-by: David Cantrell <david@cantrell.org.uk>
---
    Improved bash tab completion for 'git restore' - adds support for
    auto-completing filenames
    
    This adds tab-completion of filenames to the bash completions for git
    restore.

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-1227%2FDrHyde%2Ffilename-completion-for-git-restore-v1
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-1227/DrHyde/filename-completion-for-git-restore-v1
Pull-Request: https://github.com/git/git/pull/1227

 contrib/completion/git-completion.bash | 7 +++++++
 1 file changed, 7 insertions(+)

"David Cantrell via GitGitGadget" <gitgitgadget@gmail.com> writes:

Two questions

 - "restore" is a castrated half "checkout"; shouldn't the latter
   also be getting the same feature?

 - is "complete_index_file --committable" the right thing to use?

   It boils down to running "diff-index HEAD", which means path with
   differences from the HEAD commit is listed.  By default "restore"
   checks out the contents of the given path from the index to the
   working tree, so after "edit F && git add F", "diff-index HEAD"
   may show F in its output (i.e. F is "committable"), but "restore
   F" would be a no-op.  Which feels a bit iffy.

   Modelling it after "git add" completion, where we look for paths
   that are different between the index and the working tree, feels
   more appropriate, but I haven't thought things through.

Do you need to sprinkle return's? Instead you could just add another case arm, like

	case "$cur" in
	--conflict=*)
		... all the existing code ...
	--*)
		__gitcomp_builtin restore
		;;
+	*)
+		... whatever you want to do when
+		... $cur is not a --dashed-option
+		;;
	esac

On 13/03/2022 06:45, Junio C Hamano wrote:

`git checkout <tab>` already completes to a list of branches and tags, which is I think more useful in that case.

I'd not thought of that. --modified is better.

Liberal sprinkling of return like that seems to be the norm for the rest of the file so I stuck with it.

David Cantrell <david@cantrell.org.uk> writes:

An existing bad practice is not a good excuse to spread it even more, though.

This adds tab-completion of filenames to the bash completions for git restore.

David Cantrell (2):
  tab completion of filenames for 'git restore'
  if a file has been staged we don't want to list it

 contrib/completion/git-completion.bash | 7 +++++++
 1 file changed, 7 insertions(+)

base-commit: 1a4874565fa3b6668042216189551b98b4dc0b1b
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-1227%2FDrHyde%2Ffilename-completion-for-git-restore-v2
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-1227/DrHyde/filename-completion-for-git-restore-v2
Pull-Request: https://github.com/git/git/pull/1227

Range-diff vs v1:

 1:  2bb8f1cb1c4 = 1:  2bb8f1cb1c4 tab completion of filenames for 'git restore'
 -:  ----------- > 2:  16aa4d0b2e4 if a file has been staged we don't want to list it

From: David Cantrell <david@cantrell.org.uk>

The previous use of --committable would include files that had been `git add`ed, but for which a simple `git restore filename` doesn't work. --modifed only lists those whose modifications have not been staged.

Signed-off-by: David Cantrell <david@cantrell.org.uk>
---
 contrib/completion/git-completion.bash | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

On 15/03/22 07.52, David Cantrell via GitGitGadget wrote:

The patch title you wrote descriptive mood instead of imperative one. It should have been "don't list staged files".

From: David Cantrell <david@cantrell.org.uk>

If no --args are present after 'git restore' it assumes that you want to tab-complete one of the files with uncommitted changes

Signed-off-by: David Cantrell <david@cantrell.org.uk>
---
 contrib/completion/git-completion.bash | 7 +++++++
 1 file changed, 7 insertions(+)

"David Cantrell via GitGitGadget" <gitgitgadget@gmail.com> writes:

Why two patches? The second separate patch makes the topic look as if "oops, the first step designed a wrong behaviour and here is a brown paper bag fix-up".

Junio C Hamano <gitster@pobox.com> writes:

Sorry, I forgot the obligatory clarification for new contributors.

This project gives all contributors a chance to pretend to be a "perfect human". When sending an updated patch (or patch series), contributors are encouraged to hide^W correct their earlier mistakes and present a perfect logical progression that they (would have, if they were perfect) followed to arrive at a perfect end result.

So, instead of having step 1 that uses --committable without justifying why it was chosen, and then change mind in step 2 to replace it with --modified, have a single patch that uses --modified, and explain in the proposed log message that --committable and --modified may be possibilities, and why the patch chose to use the latter. The resulting history without a flip-flop in the middle is easier to use by future developers to understand the reasoning behind each change.

Thanks.

From: David Cantrell <david@cantrell.org.uk>

If no --args are present after 'git restore' it assumes that you want to tab-complete one of the files with unstaged uncommitted changes.

If a file has been staged we don't want to list it, as restoring those requires a slightly more complex `git restore --staged`, so we only list those files that are --modified. While --committable also looks like a good candidate, that includes changes that have been staged.

Signed-off-by: David Cantrell <david@cantrell.org.uk>
---
    Improved bash tab completion for 'git restore' - adds support for
    auto-completing filenames
    
    This adds tab-completion of filenames to the bash completions for git
    restore.

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-1227%2FDrHyde%2Ffilename-completion-for-git-restore-v3
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-1227/DrHyde/filename-completion-for-git-restore-v3
Pull-Request: https://github.com/git/git/pull/1227

Range-diff vs v2:

 1:  2bb8f1cb1c4 ! 1:  779744b9fc5 tab completion of filenames for 'git restore'
     @@ Commit message
          tab completion of filenames for 'git restore'
      
          If no --args are present after 'git restore' it assumes that you want
     -    to tab-complete one of the files with uncommitted changes
     +    to tab-complete one of the files with unstaged uncommitted changes.
     +
     +    If a file has been staged we don't want to list it, as restoring those
     +    requires a slightly more complex `git restore --staged`, so we only list
     +    those files that are --modified. While --committable also looks like
     +    a good candidate, that includes changes that have been staged.
      
          Signed-off-by: David Cantrell <david@cantrell.org.uk>
      
       ## contrib/completion/git-completion.bash ##
      @@ contrib/completion/git-completion.bash: _git_restore ()
     - 	case "$cur" in
     - 	--conflict=*)
     - 		__gitcomp "diff3 merge zdiff3" "" "${cur##--conflict=}"
     -+		return
     - 		;;
     - 	--source=*)
     - 		__git_complete_refs --cur="${cur##--source=}"
     -+		return
     - 		;;
       	--*)
       		__gitcomp_builtin restore
     -+		return
       		;;
     ++	*)
     ++		if __git rev-parse --verify --quiet HEAD >/dev/null; then
     ++			__git_complete_index_file "--modified"
     ++		fi
       	esac
     -+
     -+	if __git rev-parse --verify --quiet HEAD >/dev/null; then
     -+		__git_complete_index_file "--committable"
     -+	fi
       }
       
     - __git_revert_inprogress_options=$__git_sequencer_inprogress_options
 2:  16aa4d0b2e4 < -:  ----------- if a file has been staged we don't want to list it

 contrib/completion/git-completion.bash | 4 ++++
 1 file changed, 4 insertions(+)

"David Cantrell via GitGitGadget" <gitgitgadget@gmail.com> writes:

Perhaps

    Subject: [PATCH v3] completion: complete modified files for 'git restore'

cf. Documentation/SubmittingPatches::[[summary-section]]

Since it is our convention that the first paragraph talks about the current behaviour, i.e. without the proposed changes applied, in the present tense, I'd assume the above is what the current code does.

What do you mean by "--args" in this sentence? Dashed-options? I am getting the same set of files whose name begins with 'a' from these two:

 $ git restore a<TAB>
 $ git restore --staged a<TAB>

so, with or without --dashed-options, we complete one of the files, whether they have any modifications.

Perhaps you meant to say more like:

    When completing a non-option argument to 'git restore', the
    command line completion support offers names of the files
    present in the working tree as candidates.

to describe the status quo; to hint what the shortcoming of the current behaviour is, we may want to add a bit more, perhaps append the following at the end of that first paragraph:

    But many of these files may not have any changes, and running
    "restore" on them would be a no-op.  Listing only the files, to
    which doing "restore" is not a no-op, would reduce the clutter.
    
Then we'd continue with the solution, while explaining why the exact
choice between modified vs committable was made:

    Offer only the files that are different from the index, to match
    the default behaviour of "git restore" that checks out the
    contents last added to the index to the working tree.  We could
    instead show the files that are different between the index and
    HEAD, and that is more suittable if "git restore --staged" is
    being completed, but this should do for now.

or something. The last part is written in such a way to explicitly signal to future developers that we know we did not do a perfect job and we do not mind if they extend the logic to use something other than "--modified" when appropriate. For example, they could build on this solution to make it inspect the command line for "--staged" and "--source" and drive "diff-index" differently to grab the paths that are offered. We just do not do that at least for now, but we have no objection if other people do so in the future.

Thanks.  Will queue as-is for now.

On 16/03/2022 00:44, Junio C Hamano wrote:

Yes.

If --staged is present I think it falls back to the standard behaviour of attempting to complete to any file it can find

That makes sense.

Thank you.