Start integrating Buck into rake and Crazy Fun.

Try it out by finding a target that exists in a BUCK
file but not in the build.desc file located in the
same directory. eg:

 ./go //java/client/src/org/openqa/selenium:selenium-java

You should see the build output from Buck as it
builds your target.

Author: shs96c

Rakefile

@@ -14,6 +14,9 @@ Rake.application.instance_variable_set "@name", "go"
 orig_verbose = verbose
 verbose(false)
 
+# Buck integration
+require 'rake-tasks/buck'
+
 # The CrazyFun build grammar. There's no magic here, just ruby
 require 'rake-tasks/crazy_fun'
 require 'rake-tasks/crazy_fun/mappings/export'

rake-tasks/buck.rb

@@ -0,0 +1,106 @@
+require 'open3'
+
+module Buck
+
+  def self.buck_cmd
+    @@buck_cmd ||= (
+      lambda { |command, target, &block|
+        cmd = "buck #{command} #{target}"
+        output = ''
+        err = ''
+        Open3.popen3(cmd) do |stdin, stdout, stderr, wait_thr|
+          stdin.close
+
+          while line = stderr.gets
+            if command == 'build'
+              puts line
+            end
+            err += line
+          end
+
+          while line = stdout.gets
+            output += line
+          end
+
+          # In jruby, wait_thr always appears to be nil. *sigh*
+#          if !wait_thr.value.success?
+#            raise "Unable to execute command: " + err.to_s
+#          end
+        end
+
+        block.call(output.to_s) if block
+      }
+    )
+
+    #block.call(output) if block
+  end
+
+  def self.enhance_task(task)
+    class <<task
+      def needed?
+        true
+      end
+
+      attr_reader :out
+      def out
+        @out ||= Buck::find_buck_out(name)
+      end
+    end
+
+    task
+  end
+
+  def self.find_buck_out(target)
+    out = nil
+
+    Buck::buck_cmd.call('targets', "--show-output #{target}") do |output|
+      sections = output.chomp.split
+      # Not all buck rules have an output file.
+      if sections.size > 1
+        out = output.chomp.split[-1]
+      end
+    end
+
+    out
+  end
+
+end
+
+def buck(*args, &block)
+  case args[0]
+    when String
+      name = args[0].to_sym
+      prereqs = []
+    when Hash
+      name = args[0].keys[0]
+      pres = args[0][name]
+      case pres
+        when String
+          prereqs = [pres]
+        when Array
+          prereqs = pres
+        else
+          raise "I have no idea what to do with this: #{pres.class.to_s}"
+      end
+    else
+      raise "Unknown arg type: #{args[0].class.to_s}"
+  end
+
+  task = Rake::Task.task_defined?(name) ? Rake::Task[name] : Rake::Task.define_task(name)
+  task.enhance prereqs do
+    Buck::buck_cmd.call('build', name)
+    block.call if block
+  end
+
+  Buck::enhance_task(task)
+end
+
+rule /\/\/.*/ do |task|
+  # Task is a FileTask, but that's not what we need. Instead, just delegate down to buck in all cases
+
+  task.enhance do
+    Buck::buck_cmd.call('build', task.name)
+  end
+
+  Buck::enhance_task(task)
+end