Add a "match" remote dependency method (closes #9379)

git-svn-id: http://svn.rubyonrails.org/rails/tools/capistrano@7386 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

CHANGELOG

@@ -1,5 +1,7 @@
 *SVN*
 
+* Add a "match" remote dependency method [Adam Greene]
+
 * Allow auth-caching of subversion credentials to be enabled via :scm_auth_cache [tsmith]
 
 * Don't let a task trigger itself when used as the source for an "on" hook [Jamis Buck]

lib/capistrano/recipes/deploy/remote_dependency.rb

@@ -34,6 +34,36 @@ module Capistrano
         self
       end
 
+      def match(command, expect, options={})
+        expect = Regexp.new(Regexp.escape(expect.to_s)) unless expect.is_a?(Regexp)
+
+        output_per_server = {} 
+        try("#{command} ", options) do |ch, stream, out| 
+          output_per_server[ch[:server]] ||= '' 
+          output_per_server[ch[:server]] += out 
+        end 
+
+        # It is possible for some of these commands to return a status != 0
+        # (for example, rake --version exits with a 1). For this check we
+        # just care if the output matches, so we reset the success flag.
+        @success = true
+
+        errored_hosts = [] 
+        output_per_server.each_pair do |server, output| 
+          next if output =~ expect
+          errored_hosts << server 
+        end 
+
+        if errored_hosts.any?
+          @hosts = errored_hosts.join(', ')
+          output = output_per_server[errored_hosts.first]
+          @message = "the output #{output.inspect} from #{command.inspect} did not match #{expect.inspect}"
+          @success = false
+        end 
+
+        self 
+      end
+
       def or(message)
         @message = message
         self
@@ -55,6 +85,7 @@ module Capistrano
         return unless @success # short-circuit evaluation
         configuration.run(command, options) do |ch,stream,out|
           warn "#{ch[:server]}: #{out}" if stream == :err
+          yield ch, stream, out if block_given?
         end
       rescue Capistrano::CommandError => e
         @success = false