Adds JSON output to `outdated` command

After some musing on brunophilipe/Cakebrew#71, I thought it would
be useful to let Cakebrew and other tools grab the outdated formulae
version information using a method more elegant than regex.

Closes Homebrew/homebrew#30693.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>

1 files changed, 30 insertions, 8 deletions

diff --git a/Library/Homebrew/cmd/outdated.rb b/Library/Homebrew/cmd/outdated.rb
index 6ae5254e5..10fa36953 100644
--- a/Library/Homebrew/cmd/outdated.rb
+++ b/Library/Homebrew/cmd/outdated.rb
@@ -3,14 +3,10 @@ require 'keg'
 
 module Homebrew
   def outdated
-    formulae = ARGV.resolved_formulae.any? ? ARGV.resolved_formulae : Formula.installed
-
-    outdated = outdated_brews(formulae) do |f, versions|
-      if ($stdout.tty? || ARGV.verbose?) && !ARGV.flag?("--quiet")
-        puts "#{f.full_name} (#{versions*', '} < #{f.pkg_version})"
-      else
-        puts f.full_name
-      end
+    if ARGV.json == "v1"
+      outdated = print_outdated_json
+    else
+      outdated = print_outdated
     end
     Homebrew.failed = ARGV.resolved_formulae.any? && outdated.any?
   end
@@ -37,4 +33,30 @@ module Homebrew
       end
     end.compact
   end
+
+  def formulae_to_check
+    ARGV.resolved_formulae.any? ? ARGV.resolved_formulae : Formula.installed
+  end
+
+  def print_outdated
+    outdated_brews(formulae_to_check) do |f, versions|
+      if ($stdout.tty? || ARGV.verbose?) && !ARGV.flag?("--quiet")
+        puts "#{f.full_name} (#{versions*', '} < #{f.pkg_version})"
+      else
+        puts f.full_name
+      end
+    end
+  end
+
+  def print_outdated_json
+    json = []
+    outdated = outdated_brews(formulae_to_check) do |f, versions|
+      json << {:name => f.name,
+               :installed_versions => versions.collect(&:to_s),
+               :current_version => f.pkg_version.to_s}
+    end
+    puts Utils::JSON.dump(json)
+
+    outdated
+  end
 end