add --installed to json info

Closes Homebrew/homebrew#29315.

Library/Contributions/brew_bash_completion.sh

@@ -222,7 +222,7 @@ _brew_info ()
     local cur="${COMP_WORDS[COMP_CWORD]}"
     case "$cur" in
     --*)
-        __brewcomp "--all --github --json=v1"
+        __brewcomp "--all --github --installed --json=v1"
         return
         ;;
     esac

Library/Contributions/manpages/brew.1.md

@@ -160,10 +160,13 @@ Note that these flags should only appear after a command.
 
     To view formula history locally: `brew log -p <formula>`.
 
-  * `info --json=<version>` <formula>:
+  * `info --json=<version>` (--all|--installed|<formula>):
     Print a JSON representation of <formula>. Currently the only accepted value
     for <version> is `v1`.
 
+    Pass `--all` to get information on all formulae, or `--installed` to get
+    information on all installed formulae.
+
   * `install [--debug] [--env=<std|super>] [--ignore-dependencies] [--only-dependencies] [--cc=<compiler>] [--build-from-source] [--devel|--HEAD]` <formula>:
     Install <formula>.
 

Library/Homebrew/cmd/info.rb

@@ -41,8 +41,14 @@ module Homebrew extend self
   end
 
   def print_json
-    formulae = ARGV.include?("--all") ? Formula : ARGV.formulae
-    json = formulae.map {|f| f.to_hash}
+    ff = if ARGV.include? "--all"
+           Formula
+         elsif ARGV.include? "--installed"
+           Formula.installed
+         else
+           ARGV.formulae
+         end
+    json = ff.map {|f| f.to_hash}
     if json.size == 1
       puts Utils::JSON.dump(json.pop)
     else

Library/Homebrew/formula.rb

@@ -369,6 +369,7 @@ class Formula
     include Enumerable
   end
 
+  # An array of all installed formulae
   def self.installed
     return [] unless HOMEBREW_CELLAR.directory?
 

share/man/man1/brew.1

@@ -177,9 +177,12 @@ Open a browser to the GitHub History page for formula \fIformula\fR\.
 To view formula history locally: \fBbrew log \-p <formula>\fR\.
 .
 .TP
-\fBinfo \-\-json=<version>\fR \fIformula\fR
+\fBinfo \-\-json=<version>\fR (\-\-all|\-\-installed|\fIformula\fR)
 Print a JSON representation of \fIformula\fR\. Currently the only accepted value for \fIversion\fR is \fBv1\fR\.
 .
+.IP
+Pass \fB\-\-all\fR to get information on all formulae, or \fB\-\-installed\fR to get information on all installed formulae\.
+.
 .TP
 \fBinstall [\-\-debug] [\-\-env=<std|super>] [\-\-ignore\-dependencies] [\-\-only\-dependencies] [\-\-cc=<compiler>] [\-\-build\-from\-source] [\-\-devel|\-\-HEAD]\fR \fIformula\fR
 Install \fIformula\fR\.