Various improvements for brew command

- Add a (large) speedup by moving some logic to Bash for the typical
  case of a normal or dev-cmd, Bash or Ruby command.
- Make `brew command` a non-developer command, I don't think it makes
  sense to consider it something needed for developing Homebrew.
- Update the manpage/tests/RBI accordingly.

Co-authored-by: Carlo Cabrera <[email protected]>

Library/Homebrew/brew.sh

@@ -120,6 +120,11 @@ case "$*" in
     source "${HOMEBREW_LIBRARY}/Homebrew/formula_path.sh"
     homebrew-formula-path "$@" && exit 0
     ;;
+  # falls back to cmd/command.rb on a non-zero return
+  command*)
+    source "${HOMEBREW_LIBRARY}/Homebrew/command_path.sh"
+    homebrew-command-path "$@" && exit 0
+    ;;
 esac
 
 #####

Library/Homebrew/dev-cmd/command.rb → Library/Homebrew/cmd/command.rb

@@ -5,7 +5,7 @@
 require "commands"
 
 module Homebrew
-  module DevCmd
+  module Cmd
     class Command < AbstractCommand
       cmd_args do
         description <<~EOS

Library/Homebrew/command_path.sh

@@ -0,0 +1,46 @@
+# does the quickest output of brew command possible for the basic cases of an
+# official Bash or Ruby normal or dev-cmd command.
+# HOMEBREW_LIBRARY is set by brew.sh
+# shellcheck disable=SC2154
+homebrew-command-path() {
+  case "$1" in
+    # check we actually have command and not e.g. commandsomething
+    command) ;;
+    *) return 1 ;;
+  esac
+
+  local first_command found_command
+  for arg in "$@"
+  do
+    if [[ -z "${first_command}" && "${arg}" == "command" ]]
+    then
+      first_command=1
+      continue
+    elif [[ -f "${HOMEBREW_LIBRARY}/Homebrew/cmd/${arg}.sh" ]]
+    then
+      echo "${HOMEBREW_LIBRARY}/Homebrew/cmd/${arg}.sh"
+      found_command=1
+    elif [[ -f "${HOMEBREW_LIBRARY}/Homebrew/dev-cmd/${arg}.sh" ]]
+    then
+      echo "${HOMEBREW_LIBRARY}/Homebrew/dev-cmd/${arg}.sh"
+      found_command=1
+    elif [[ -f "${HOMEBREW_LIBRARY}/Homebrew/cmd/${arg}.rb" ]]
+    then
+      echo "${HOMEBREW_LIBRARY}/Homebrew/cmd/${arg}.rb"
+      found_command=1
+    elif [[ -f "${HOMEBREW_LIBRARY}/Homebrew/dev-cmd/${arg}.rb" ]]
+    then
+      echo "${HOMEBREW_LIBRARY}/Homebrew/dev-cmd/${arg}.rb"
+      found_command=1
+    else
+      return 1
+    fi
+  done
+
+  if [[ -n "${found_command}" ]]
+  then
+    return 0
+  else
+    return 1
+  fi
+}

Library/Homebrew/test/dev-cmd/command_spec.rb → Library/Homebrew/test/cmd/command_spec.rb

@@ -1,9 +1,9 @@
 # frozen_string_literal: true
 
 require "cmd/shared_examples/args_parse"
-require "dev-cmd/command"
+require "cmd/command"
 
-RSpec.describe Homebrew::DevCmd::Command do
+RSpec.describe Homebrew::Cmd::Command do
   it_behaves_like "parseable arguments"
 
   it "returns the file for a given command", :integration_test do

docs/Manpage.md

@@ -153,6 +153,10 @@ old. This can be adjusted with `HOMEBREW_CLEANUP_MAX_AGE_DAYS`.
 : Only prune the symlinks and directories from the prefix and remove no other
   files.
 
+### `command` *`command`* \[...\]
+
+Display the path to the file being used when invoking `brew` *`cmd`*.
+
 ### `commands` \[`--quiet`\] \[`--include-aliases`\]
 
 Show lists of built-in and external commands.
@@ -1985,10 +1989,6 @@ Display the source of a *`formula`* or *`cask`*.
 
 : Treat all named arguments as casks.
 
-### `command` *`command`* \[...\]
-
-Display the path to the file being used when invoking `brew` *`cmd`*.
-
 ### `contributions` \[--user=*`email|username`*\] \[*`--repositories`*`=`\] \[*`--csv`*\]
 
 Summarise contributions to Homebrew repositories.

manpages/brew.1

@@ -93,6 +93,8 @@ Scrub the cache, including downloads for even the latest versions\. Note that do
 .TP
 \fB\-\-prune\-prefix\fP
 Only prune the symlinks and directories from the prefix and remove no other files\.
+.SS "\fBcommand\fP \fIcommand\fP \fR[\.\.\.]"
+Display the path to the file being used when invoking \fBbrew\fP \fIcmd\fP\&\.
 .SS "\fBcommands\fP \fR[\fB\-\-quiet\fP] \fR[\fB\-\-include\-aliases\fP]"
 Show lists of built\-in and external commands\.
 .TP
@@ -1259,8 +1261,6 @@ Treat all named arguments as formulae\.
 .TP
 \fB\-\-cask\fP
 Treat all named arguments as casks\.
-.SS "\fBcommand\fP \fIcommand\fP \fR[\.\.\.]"
-Display the path to the file being used when invoking \fBbrew\fP \fIcmd\fP\&\.
 .SS "\fBcontributions\fP \fR[\-\-user=\fIemail|username\fP] \fR[\fI\-\-repositories\fP\fB=\fP] \fR[\fI\-\-csv\fP]"
 Summarise contributions to Homebrew repositories\.
 .TP