Remove duplicate container fish completion

[soraxas]

- What I did
Fix multiple suggestions for one signle container in fish completion file.

- How I did it
Changed \n to \t in container list's format

- How to verify it
Background info: fish completion will take a text in the format of

foo1\tbar1\nfoo2\tbar2\n...

format and interpret it as having two suggestion, 1st with the name foo1 with description bar1, and so on. (i.e. \t denotes description, and \n denotes new suggestion.

This is a test of having only two containers running.

Current behaviour:

With the patch:

- Description for the changelog

Use container's name as description in fish completion suggestion.

- A picture of a cute animal (not mandatory but encouraged)

[thaJeztah]

What if I (in your example) try to use docker stop interest<tab>, would it complete to the ID of the container, instead of the name?

[soraxas]

Now that I think of it, probably using the friendly name as the completion makes more sense (and hash as description, as I was afraid of changing too much previously.

To answer your question, yes it will still complete as it considers the description as well (in fact it consider any substring afaik)

There were 4 completions in this gif.

1. Using 2nd container's name
2. Using 2nd container's hash (beginning)
3. Using 1st container's hash (beginning)
   • this is the gracious_nobel one, for you to locate yourself in the gif.
4. Using 2nd container's hash (some substring in middle)

If you agree, I will update the changes (i.e. swap {{.ID}} and {{.NAME}}

[thaJeztah]

Sorry for the delay; I'm still a bit on the fence, as the completion will replace something I typed, instead of completing it 🤔

/cc @silvin-lubecki any thoughts?

[krobelus]

I have thought about doing the same, however, I think descriptions should be used to convey additional information about an image/container, which #1623 does quite nicely. Therefore both IDs and names should remain as completion options - they don't hurt anyone.

Currently the container IDs and names are ordered alphabetically, because that's what fish does by default.
This doesn't make a ton of sense. Docker already provides a sensible order.
My suggestion would be to use the --keep-order option
to prevent fish from sorting them, and use a small snippet in __fish_print_docker_containers to first print all human-friendly names, and then all IDs.

set -l all_containers (docker ps -a --no-trunc --format "{{.ID}}\n{{.Names}}")
set -l ids (string match -r '^\w{64}$' $all_containers)
set -l names (string match -rv '^\w{64}$' $all_containers)
string join \n $names $ids

adding --keep-order would look like

-complete -c docker -A -f -n '__fish_seen_subcommand_from attach' -a '(__fish_print_docker_containers running)' -d 
+complete --keep-order -c docker -A -f -n '__fish_seen_subcommand_from attach' -a '(__fish_print_docker_containers running)' -d "Container"