Omit aliases from completions

[MikeMcQuaid]

Fixes https://github.com/orgs/Homebrew/discussions/6836

• Avoid suggesting internal aliases because they duplicate canonical commands.
• Keep alias expansion for option completion after users type an alias.
• Regenerate bash, fish, zsh and internal command completion data.

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[Copilot]

Pull request overview

This PR updates Homebrew’s shell completion generation to omit internal command aliases from top-level command suggestions (so users see canonical commands only), while still expanding internal aliases when the user types one so option/subcommand completion continues to work.

Changes:

• Stop including internal command aliases in the cached/internal command lists used by completions.
• Add internal-alias expansion hooks in bash/fish completions and adjust zsh generation to avoid emitting per-alias completion functions.
• Add tests to ensure aliases are omitted from command suggestion lists but still expand correctly for completion dispatch.

Reviewed changes

Copilot reviewed 10 out of 10 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
Library/Homebrew/test/completions_spec.rb	Adds expectations that bash/zsh/fish completion generation omits alias command suggestions but retains alias expansion for dispatch.
Library/Homebrew/test/commands_spec.rb	Adds coverage ensuring rebuilt command lists don’t include internal aliases.
Library/Homebrew/completions/fish.erb	Introduces alias expansion helper and filters out internal aliases from suggested commands.
Library/Homebrew/completions/bash.erb	Filters alias commands from suggestions and expands internal aliases before dispatching to subcommand completion.
Library/Homebrew/completions.rb	Generates completions from canonical command lists (no aliases) and injects alias-expansion data into templates.
Library/Homebrew/commands.rb	Ensures rebuilt completion command lists omit internal aliases by default.
completions/zsh/_brew	Regenerated zsh completion output without per-alias completion functions.
completions/internal_commands_list.txt	Regenerated internal command list omitting internal alias entries.
completions/fish/brew.fish	Regenerated fish completion output with alias expansion and alias omission in suggestions.
completions/bash/brew	Regenerated bash completion output with alias expansion and alias omission in suggestions.

Comments suppressed due to low confidence (2)

Library/Homebrew/completions/bash.erb:165

• __brew_list_aliases appears to be dead code now: it's defined but no longer referenced anywhere in the bash completion script (it used to be used by __brew_complete_commands). Consider removing this function (and the homebrew-aliases comment) to reduce generated completion size and avoid maintaining unused code.

# https://github.com/Homebrew/homebrew-aliases
__brew_list_aliases() {
  local aliases_dir="${HOME}/.brew-aliases"
  local pattern="^# alias: brew ([[:alnum:]-]+)$"
  local -a aliases

  [[ ! -d ${aliases_dir} ]] && return

  for file in "${aliases_dir}"/*; do
    [[ ! -f ${file} ]] && continue
    while read -r line; do
      if [[ ${line} =~ ${pattern} ]]; then
        aliases+=("${BASH_REMATCH[1]}")
        break
      fi
    done < "${file}"
  done
  [[ -n ${aliases[*]+"${aliases[*]}"} ]] && echo "${aliases[@]}"
}

completions/bash/brew:168

• __brew_list_aliases is defined but not referenced anywhere in the generated bash completion file anymore. It looks like leftover code from when command completion appended homebrew-aliases entries; removing it would reduce file size and avoid carrying unused logic.

# https://github.com/Homebrew/homebrew-aliases
__brew_list_aliases() {
  local aliases_dir="${HOME}/.brew-aliases"
  local pattern="^# alias: brew ([[:alnum:]-]+)$"
  local -a aliases

  [[ ! -d ${aliases_dir} ]] && return

  for file in "${aliases_dir}"/*; do
    [[ ! -f ${file} ]] && continue
    while read -r line; do
      if [[ ${line} =~ ${pattern} ]]; then
        aliases+=("${BASH_REMATCH[1]}")
        break
      fi
    done < "${file}"
  done
  [[ -n ${aliases[*]+"${aliases[*]}"} ]] && echo "${aliases[@]}"
}

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[yermulnik]

This was harsh 😕 This change also omits user-defined aliases which is pretty inconvenient 😢

> __brew_list_aliases
list-depends list-installed-files list-installed-packages-by-date list-installed-packages-by-name list-installed-packages-versions list-upward-depends list-upward-depends-tree show which

Typing most of these verbatim is a burden now 😞

The linked discussion is two-people's opinion with zero thumb-ups and quite debatable grounding. And is actually about builtin aliases while this PR just dropped completion for aliases defined by users.
Moreover I don't know where from those folks learn about existing builtin aliases as I used to find them from command-line completion (the brew <tab> thing). So they seemed to just shoot their leg by asking to cut short this option just because they thought it could clean up the output (at the moment brew <tab> suggests 110 completion possibilities, whereas cutting off a single dozen of them can't make the list any notably concise I guess) 😕

Could this please be reverted or re-implemented to allow for user-defined aliases?
Would you like an issue or a discussion for this if you're not objecting against the ask?
Thank you.

[yermulnik]

Coincidentally it was me only ~1,5 yrs ago adding Bash completion for user-defined aliases: #18791

By the look of it adding #18791 back won't revert what this PR was targeting I guess: the builtin aliases won't become part of Bash completion whilst the user-defined aliases — will.

[MikeMcQuaid]

The linked discussion is two-people's opinion with zero thumb-ups and quite debatable grounding.

And your response here is just one person's opinion. I agree with them that this was a good change which is why it was made.

Could this please be reverted or re-implemented to allow for user-defined aliases?

Will review a PR for this for just user-defined aliases.

[yermulnik]

Could this please be reverted or re-implemented to allow for user-defined aliases?

Will review a PR for this for just user-defined aliases.

The #18791 was specifically and only for user-defined aliases.
Let me pull-request it again 👍🏻

[MikeMcQuaid]

@yermulnik beat you to it: #22693. Can you try that out and let me know if it's what you are expecting?

[yermulnik]

Appreciate your time and effort ❤️
I tested Bash completion file and it works as expected 🥳 Many thanks 👍🏻