info: Add JSON output

Output JSON with the --json=v1 option. Output is in an array, and
supports one or more formulae (or all, with the --all option).

Why 'v1'? The format is unstable, presumably we'll deprecate it
someday. It should be solid by Homebrew 1.0.

Closes #13299.

1 files changed, 22 insertions, 0 deletions

diff --git a/Library/Homebrew/cmd/info.rb b/Library/Homebrew/cmd/info.rb
index c9040eac6..6fe43e687 100644
--- a/Library/Homebrew/cmd/info.rb
+++ b/Library/Homebrew/cmd/info.rb
@@ -4,6 +4,16 @@ require 'keg'
 
 module Homebrew extend self
   def info
+    # eventually we'll solidify an API, but we'll keep old versions
+    # awhile around for compatibility
+    if ARGV.json == "v1"
+      print_json
+    else
+      print_info
+    end
+  end
+
+  def print_info
     if ARGV.named.empty?
       if ARGV.include? "--all"
         Formula.each do |f|
@@ -20,6 +30,18 @@ module Homebrew extend self
     end
   end
 
+  def print_json
+    require 'vendor/multi_json'
+
+    formulae = ARGV.include?("--all") ? Formula : ARGV.formulae
+    json = formulae.map {|f| f.to_hash}
+    if json.size == 1
+      puts MultiJson.encode json.pop
+    else
+      puts MultiJson.encode json
+    end
+  end
+
   def github_fork
     if which 'git' and (HOMEBREW_REPOSITORY/".git").directory?
       if `git remote -v` =~ %r{origin\s+(https?://|git(?:@|://))github.com[:/](.+)/homebrew}