Refactor Runner avilability checking

* Allows tests to run on JRuby
* Adds a query method to know if the Runner is available
* Uses the query method to determind best_runner
* Puts query method on class because it's not instance's responsibility

.travis.yml

@@ -1,9 +1,8 @@
 rvm:
-  - 1.9.2
   - 1.9.3
   - 2.0.0
+  - jruby-19mode
 
 matrix:
   allow_failures:
-    - rvm: jruby-19mode
     - rvm: rbx-19mode

lib/cocaine/command_line.rb

@@ -15,15 +15,6 @@ def path=(supplemental_path)
         @supplemental_environment['PATH'] = (Array(supplemental_path) + [ENV['PATH']]).join(File::PATH_SEPARATOR)
       end
 
-      def posix_spawn_available?
-        @posix_spawn_available ||= begin
-          require 'posix/spawn'
-          true
-        rescue LoadError => e
-          false
-        end
-      end
-
       def environment
         @supplemental_environment ||= {}
       end
@@ -40,12 +31,16 @@ def unfake!
         @runner = nil
       end
 
+      def java?
+        RUBY_PLATFORM =~ /java/
+      end
+
       private
 
       def best_runner
-        return PosixRunner.new   if posix_spawn_available?
-        return ProcessRunner.new if Process.respond_to?(:spawn)
-        BackticksRunner.new
+        [PosixRunner, ProcessRunner, BackticksRunner].detect do |runner|
+          runner.supported?
+        end.new
       end
     end
 

lib/cocaine/command_line/runners/backticks_runner.rb

@@ -5,6 +5,13 @@
 module Cocaine
   class CommandLine
     class BackticksRunner
+      def self.supported?
+        true
+      end
+
+      def supported?
+        self.class.supported?
+      end
 
       def call(command, env = {})
         with_modified_environment(env) do

lib/cocaine/command_line/runners/fake_runner.rb

@@ -3,6 +3,13 @@
 module Cocaine
   class CommandLine
     class FakeRunner
+      def self.supported?
+        false
+      end
+
+      def supported?
+        self.class.supported?
+      end
 
       attr_reader :commands
 

lib/cocaine/command_line/runners/popen_runner.rb

@@ -3,6 +3,14 @@
 module Cocaine
   class CommandLine
     class PopenRunner
+      def self.supported?
+        true
+      end
+
+      def supported?
+        self.class.supported?
+      end
+
       def call(command, env = {})
         with_modified_environment(env) do
           IO.popen(command, "r") do |pipe|

lib/cocaine/command_line/runners/posix_runner.rb

@@ -3,31 +3,45 @@
 module Cocaine
   class CommandLine
     class PosixRunner
-      if Cocaine::CommandLine.posix_spawn_available?
-
-        def call(command, env = {})
-          input, output = IO.pipe
-          pid = spawn(env, command, :out => output)
-          output.close
-          result = ""
-          while partial_result = input.read(8192)
-            result << partial_result
-          end
-          waitpid(pid)
-          result
+      def self.available?
+        begin
+          require 'posix/spawn'
+          true
+        rescue LoadError => e
+          false
         end
+      end
 
-        private
+      def self.supported?
+        available? && !Cocaine::CommandLine.java?
+      end
 
-        def spawn(*args)
-          POSIX::Spawn.spawn(*args)
-        end
+      def supported?
+        self.class.supported?
+      end
 
-        def waitpid(pid)
-          Process.waitpid(pid)
+      def call(command, env = {})
+        input, output = IO.pipe
+        pid = spawn(env, command, :out => output)
+        output.close
+        result = ""
+        while partial_result = input.read(8192)
+          result << partial_result
         end
+        waitpid(pid)
+        result
+      end
 
+      private
+
+      def spawn(*args)
+        POSIX::Spawn.spawn(*args)
+      end
+
+      def waitpid(pid)
+        Process.waitpid(pid)
       end
+
     end
   end
 end

lib/cocaine/command_line/runners/process_runner.rb

@@ -3,33 +3,41 @@
 module Cocaine
   class CommandLine
     class ProcessRunner
-      if Process.respond_to?(:spawn)
-
-        def call(command, env = {})
-          input, output = IO.pipe
-          pid = spawn(env, command, :out => output)
-          output.close
-          result = input.read
-          waitpid(pid)
-          result
-        end
+      def self.available?
+        Process.respond_to?(:spawn)
+      end
 
-        private
+      def self.supported?
+        available? && !Cocaine::CommandLine.java?
+      end
 
-        def spawn(*args)
-          Process.spawn(*args)
-        end
+      def supported?
+        self.class.supported?
+      end
 
-        def waitpid(pid)
-          begin
-            Process.waitpid(pid)
-          rescue Errno::ECHILD => e
-            # In JRuby, waiting on a finished pid raises.
-          end
-        end
+      def call(command, env = {})
+        input, output = IO.pipe
+        pid = spawn(env, command, :out => output)
+        output.close
+        result = input.read
+        waitpid(pid)
+        result
+      end
 
+      private
+
+      def spawn(*args)
+        Process.spawn(*args)
+      end
+
+      def waitpid(pid)
+        begin
+          Process.waitpid(pid)
+        rescue Errno::ECHILD => e
+          # In JRuby, waiting on a finished pid raises.
+        end
       end
+
     end
   end
 end
-

lib/cocaine/exceptions.rb

@@ -1,8 +1,8 @@
 # coding: UTF-8
 
 module Cocaine
-  class CommandLineError     < StandardError; end
+  class CommandLineError < StandardError; end
   class CommandNotFoundError < CommandLineError; end
-  class ExitStatusError      < CommandLineError; end
-  class InterpolationError   < CommandLineError; end
+  class ExitStatusError < CommandLineError; end
+  class InterpolationError < CommandLineError; end
 end

spec/cocaine/command_line/runners/backticks_runner_spec.rb

@@ -1,20 +1,22 @@
 require 'spec_helper'
 
 describe Cocaine::CommandLine::BackticksRunner do
-  it_behaves_like 'a command that does not block'
+  if Cocaine::CommandLine::BackticksRunner.supported?
+    it_behaves_like 'a command that does not block'
 
-  it 'runs the command given' do
-    subject.call("echo hello").should == "hello\n"
-  end
+    it 'runs the command given' do
+      subject.call("echo hello").should == "hello\n"
+    end
 
-  it 'modifies the environment and runs the command given' do
-    subject.call("echo $yes", {"yes" => "no"}).should == "no\n"
-  end
+    it 'modifies the environment and runs the command given' do
+      subject.call("echo $yes", {"yes" => "no"}).should == "no\n"
+    end
 
-  it 'sets the exitstatus when a command completes' do
-    subject.call("ruby -e 'exit 0'")
-    $?.exitstatus.should == 0
-    subject.call("ruby -e 'exit 5'")
-    $?.exitstatus.should == 5
+    it 'sets the exitstatus when a command completes' do
+      subject.call("ruby -e 'exit 0'")
+      $?.exitstatus.should == 0
+      subject.call("ruby -e 'exit 5'")
+      $?.exitstatus.should == 5
+    end
   end
 end

spec/cocaine/command_line/runners/popen_runner_spec.rb

@@ -1,21 +1,22 @@
 require 'spec_helper'
 
 describe Cocaine::CommandLine::PopenRunner do
-  it_behaves_like 'a command that does not block'
+  if Cocaine::CommandLine::PopenRunner.supported?
+    it_behaves_like 'a command that does not block'
 
-  it 'runs the command given' do
-    subject.call("echo hello").should == "hello\n"
-  end
+    it 'runs the command given' do
+      subject.call("echo hello").should == "hello\n"
+    end
 
-  it 'modifies the environment and runs the command given' do
-    subject.call("echo $yes", {"yes" => "no"}).should == "no\n"
-  end
+    it 'modifies the environment and runs the command given' do
+      subject.call("echo $yes", {"yes" => "no"}).should == "no\n"
+    end
 
-  it 'sets the exitstatus when a command completes' do
-    subject.call("ruby -e 'exit 0'")
-    $?.exitstatus.should == 0
-    subject.call("ruby -e 'exit 5'")
-    $?.exitstatus.should == 5
+    it 'sets the exitstatus when a command completes' do
+      subject.call("ruby -e 'exit 0'")
+      $?.exitstatus.should == 0
+      subject.call("ruby -e 'exit 5'")
+      $?.exitstatus.should == 5
+    end
   end
 end
-

spec/cocaine/command_line/runners/posix_runner_spec.rb

@@ -1,7 +1,7 @@
 require 'spec_helper'
 
 describe Cocaine::CommandLine::PosixRunner do
-  if Cocaine::CommandLine::posix_spawn_available?
+  if Cocaine::CommandLine::PosixRunner.supported?
     it_behaves_like 'a command that does not block'
 
     it 'runs the command given' do
@@ -20,4 +20,3 @@
     end
   end
 end
-

spec/cocaine/command_line/runners/process_runner_spec.rb

@@ -1,7 +1,7 @@
 require 'spec_helper'
 
 describe Cocaine::CommandLine::ProcessRunner do
-  if Process.respond_to?(:spawn)
+  if Cocaine::CommandLine::ProcessRunner.supported?
     it_behaves_like "a command that does not block"
 
     it 'runs the command given' do

spec/cocaine/command_line_spec.rb

@@ -238,38 +238,39 @@
 
   describe "command execution" do
     it "uses the BackticksRunner by default" do
-      Process.stubs(:respond_to?).with(:spawn).returns(false)
-      Cocaine::CommandLine.stubs(:posix_spawn_available?).returns(false)
+      Cocaine::CommandLine::ProcessRunner.stubs(:supported?).returns(false)
+      Cocaine::CommandLine::PosixRunner.stubs(:supported?).returns(false)
 
       cmd = Cocaine::CommandLine.new("echo", "hello")
+
       cmd.runner.class.should == Cocaine::CommandLine::BackticksRunner
     end
 
     it "uses the ProcessRunner on 1.9 and it's available" do
-      Process.stubs(:respond_to?).with(:spawn).returns(true)
-      Cocaine::CommandLine.stubs(:posix_spawn_available?).returns(false)
+      Cocaine::CommandLine::ProcessRunner.stubs(:supported?).returns(true)
+      Cocaine::CommandLine::PosixRunner.stubs(:supported?).returns(false)
 
       cmd = Cocaine::CommandLine.new("echo", "hello")
       cmd.runner.class.should == Cocaine::CommandLine::ProcessRunner
     end
 
-    it "uses the PosixRunner if the posix-spawn gem is available" do
-      Cocaine::CommandLine.stubs(:posix_spawn_available?).returns(true)
+    it "uses the PosixRunner if the PosixRunner is available" do
+      Cocaine::CommandLine::PosixRunner.stubs(:supported?).returns(true)
 
       cmd = Cocaine::CommandLine.new("echo", "hello")
       cmd.runner.class.should == Cocaine::CommandLine::PosixRunner
     end
 
-    it "uses the BackticksRunner if the posix-spawn gem is available, but we told it to use Backticks all the time" do
-      Cocaine::CommandLine.stubs(:posix_spawn_available?).returns(true)
+    it "uses the BackticksRunner if the PosixRunner is available, but we told it to use Backticks all the time" do
+      Cocaine::CommandLine::PosixRunner.stubs(:supported?).returns(true)
       Cocaine::CommandLine.runner = Cocaine::CommandLine::BackticksRunner.new
 
       cmd = Cocaine::CommandLine.new("echo", "hello")
       cmd.runner.class.should == Cocaine::CommandLine::BackticksRunner
     end
 
-    it "uses the BackticksRunner if the posix-spawn gem is available, but we told it to use Backticks" do
-      Cocaine::CommandLine.stubs(:posix_spawn_available?).returns(true)
+    it "uses the BackticksRunner if the PosixRunner is available, but we told it to use Backticks" do
+      Cocaine::CommandLine::PosixRunner.stubs(:supported?).returns(true)
 
       cmd = Cocaine::CommandLine.new("echo", "hello", :runner => Cocaine::CommandLine::BackticksRunner.new)
       cmd.runner.class.should == Cocaine::CommandLine::BackticksRunner