search: return matches from open pull requests

When search can't find any local results, hit the GitHub API and search
the titles of pending pull requests. This will help people find the many
proposed formulae and prevent them from wasting time duplicating them.

Closes Homebrew/homebrew#9018.

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

Library/Homebrew/cmd/search.rb

@@ -9,7 +9,13 @@ module Homebrew extend self
       exec "open", "http://pdb.finkproject.org/pdb/browse.php?summary=#{ARGV.next}"
     else
       query = ARGV.first
-      search_results = search_brews query
+      rx = if query =~ %r{^/(.*)/$}
+        Regexp.new($1)
+      else
+        /.*#{Regexp.escape query}.*/i
+      end
+
+      search_results = search_brews rx
       puts_columns search_results
 
       if not query.to_s.empty? and $stdout.tty? and msg = blacklisted?(query)
@@ -20,19 +26,20 @@ module Homebrew extend self
         end
         puts msg
       end
+
+      if search_results.empty? and not blacklisted? query
+        pulls = GitHub.find_pull_requests rx
+        unless pulls.empty?
+          puts "Open pull requests matching \"#{query}\":", *pulls.map { |p| "    #{p}" }
+        end
+      end
     end
   end
 
-  def search_brews text
-    if text.to_s.empty?
+  def search_brews rx
+    if rx.to_s.empty?
       Formula.names
     else
-      rx = if text =~ %r{^/(.*)/$}
-        Regexp.new($1)
-      else
-        /.*#{Regexp.escape text}.*/i
-      end
-
       aliases = Formula.aliases
       results = (Formula.names+aliases).grep rx
 
@@ -45,5 +52,4 @@ module Homebrew extend self
       end
     end
   end
-
 end

Library/Homebrew/utils.rb

@@ -427,4 +427,28 @@ module GitHub extend self
   rescue
     []
   end
+
+  def find_pull_requests rx
+    require 'open-uri'
+    require 'vendor/multi_json'
+
+    pulls = []
+    uri = URI.parse("https://api.github.com/repos/mxcl/homebrew/pulls")
+    uri.query = "per_page=100"
+
+    open uri do |f|
+      MultiJson.decode((f.read)).each do |pull|
+        pulls << pull['html_url'] if rx.match pull['title']
+      end
+
+      uri = if f.meta['link'] =~ /rel="next"/
+        f.meta['link'].slice(URI.regexp)
+      else
+        nil
+      end
+    end while uri
+    pulls
+  rescue
+    []
+  end
 end