diff --git a/lib/guard/watcher.rb b/lib/guard/watcher.rb
index 5f7df7b..bbda600 100644
--- a/lib/guard/watcher.rb
+++ b/lib/guard/watcher.rb
@@ -9,29 +9,37 @@ module Guard
     def self.match_files(guard, files)
       guard.watchers.inject([]) do |paths, watcher|
         files.each do |file|
-          if matches = file.match(watcher.pattern)
+          if matches = watcher.match_file?(file)
             if watcher.action
-              begin 
-                if watcher.action.arity == 1
-                  result = watcher.action.call(matches)
-                else
-                  result = watcher.action.call
-                end
-              rescue
-                UI.info "Problem with watch action"
-              end
-              paths << result if result.is_a?(String) && result != ''
+              result = watcher.call_action(matches)
+              paths << Array(result) if result.respond_to?(:empty?) && !result.empty?
             else
               paths << matches[0]
             end
           end
         end
-        paths
+        paths.flatten.map { |p| p.to_s }
       end
     end
     
     def self.match_files?(guards, files)
-      guards.any? { |guard| !match_files(guard, files).empty? }
+      guards.any? do |guard|
+        guard.watchers.any? do |watcher|
+          files.any? { |file| watcher.match_file?(file) }
+        end
+      end
+    end
+    
+    def match_file?(file)
+      file.match(@pattern)
+    end
+    
+    def call_action(matches)
+      begin
+        @action.arity > 0 ? @action.call(matches) : @action.call
+      rescue
+        UI.error "Problem with watch action!"
+      end
     end
     
   end
diff --git a/spec/guard/watcher_spec.rb b/spec/guard/watcher_spec.rb
new file mode 100644
index 0000000..abaca88
--- /dev/null
+++ b/spec/guard/watcher_spec.rb
@@ -0,0 +1,135 @@
+require 'spec_helper'
+require 'guard/guard'
+
+describe Guard::Watcher do
+  
+  describe "pattern" do
+    it "should be required" do
+      expect { Guard::Watcher.new }.to raise_error(ArgumentError)
+    end
+    
+    it "should be set" do
+      Guard::Watcher.new(%|spec_helper\.rb|).pattern.should == %|spec_helper\.rb|
+    end
+  end
+  
+  describe "action" do
+    it "should set action to nil by default" do
+      Guard::Watcher.new(%|spec_helper\.rb|).action.should be_nil
+    end
+    
+    it "should set action with a block" do
+      action = lambda { |m| "spec/#{m[1]}_spec.rb" }
+      Guard::Watcher.new(%|^lib/(.*).rb|, action).action.should == action
+    end
+  end
+  
+  describe ".match_files" do
+    before(:all) { @guard = Guard::Guard.new }
+    
+    describe "a watcher's with no action" do
+      before(:all) { @guard.watchers = [Guard::Watcher.new(%|.*_spec\.rb|)] }
+      
+      it "should return paths as they came" do
+        Guard::Watcher.match_files(@guard, ['guard_rocks_spec.rb']).should == ['guard_rocks_spec.rb']
+      end
+    end
+    
+    describe "a watcher's action with an arity equal to 0" do
+      before(:all) do
+        @guard.watchers = [
+          Guard::Watcher.new(%|spec_helper\.rb|, lambda { 'spec' }),
+          Guard::Watcher.new(%|addition\.rb|,    lambda { 1 + 1 }),
+          Guard::Watcher.new(%|hash\.rb|,        lambda { Hash[:foo, 'bar'] }),
+          Guard::Watcher.new(%|array\.rb|,       lambda { ['foo', 'bar'] }),
+          Guard::Watcher.new(%|blank\.rb|,       lambda { '' }),
+          Guard::Watcher.new(%|uptime\.rb|,      lambda { `uptime > /dev/null` })
+        ]
+      end
+      
+      it "should return paths specified in the watcher's action" do
+        Guard::Watcher.match_files(@guard, ['spec_helper.rb']).should == ['spec']
+      end
+      it "should return nothing if action.call doesn't respond_to :empty?" do
+        Guard::Watcher.match_files(@guard, ['addition.rb']).should == []
+      end
+      it "should return action.call.to_a if result respond_to :empty?" do
+        Guard::Watcher.match_files(@guard, ['hash.rb']).should == ['foo', 'bar']
+      end
+      it "should return files including files from array if paths are an array" do
+        Guard::Watcher.match_files(@guard, ['spec_helper.rb', 'array.rb']).should == ['spec', 'foo', 'bar']
+      end
+      it "should return nothing if action.call return ''" do
+        Guard::Watcher.match_files(@guard, ['blank.rb']).should == []
+      end
+      it "should return nothing if action.call return nil" do
+        Guard::Watcher.match_files(@guard, ['uptime.rb']).should == []
+      end
+    end
+    
+    describe "a watcher's action with an arity equal to 1" do
+      before(:all) do
+        @guard.watchers = [
+          Guard::Watcher.new(%|lib/(.*)\.rb|,     lambda { |m| "spec/#{m[1]}_spec.rb" }),
+          Guard::Watcher.new(%|addition(.*)\.rb|, lambda { |m| 1 + 1 }),
+          Guard::Watcher.new(%|hash\.rb|,         lambda { Hash[:foo, 'bar'] }),
+          Guard::Watcher.new(%|array(.*)\.rb|,    lambda { |m| ['foo', 'bar'] }),
+          Guard::Watcher.new(%|blank(.*)\.rb|,    lambda { |m| '' }),
+          Guard::Watcher.new(%|uptime(.*)\.rb|,   lambda { |m| `uptime > /dev/null` })
+        ]
+      end
+      
+      it "should return paths after watcher's action has been called against them" do
+        Guard::Watcher.match_files(@guard, ['lib/my_wonderful_lib.rb']).should == ['spec/my_wonderful_lib_spec.rb']
+      end
+      it "should return nothing if action.call doesn't respond_to :empty?" do
+        Guard::Watcher.match_files(@guard, ['addition.rb']).should == []
+      end
+      it "should return action.call.to_a if result respond_to :empty?" do
+        Guard::Watcher.match_files(@guard, ['hash.rb']).should == ['foo', 'bar']
+      end
+      it "should return files including files from array if paths are an array" do
+        Guard::Watcher.match_files(@guard, ['lib/my_wonderful_lib.rb', 'array.rb']).should == ['spec/my_wonderful_lib_spec.rb', 'foo', 'bar']
+      end
+      it "should return nothing if action.call return ''" do
+        Guard::Watcher.match_files(@guard, ['blank.rb']).should == []
+      end
+      it "should return nothing if action.call return nil" do
+        Guard::Watcher.match_files(@guard, ['uptime.rb']).should == []
+      end
+    end
+    
+    describe "an exception is raised" do
+      before(:all) { @guard.watchers = [Guard::Watcher.new('evil.rb', lambda { raise "EVIL" })] }
+      
+      it "should display an error" do
+        Guard::UI.should_receive(:error).with("Problem with watch action!")
+        Guard::Watcher.match_files(@guard, ['evil.rb'])
+      end
+    end
+  end
+  
+  describe ".match_files?" do
+    before(:all) do
+      @guard1 = Guard::Guard.new([Guard::Watcher.new(%|.*_spec\.rb|)])
+      @guard2 = Guard::Guard.new([Guard::Watcher.new(%|spec_helper\.rb|, 'spec')])
+      @guards = [@guard1, @guard2]
+    end
+    
+    describe "with at least on watcher that match a file given" do
+      specify { Guard::Watcher.match_files?(@guards, ['lib/my_wonderful_lib.rb', 'guard_rocks_spec.rb']).should be_true }
+    end
+    
+    describe "with no watcher matching a file given" do
+      specify { Guard::Watcher.match_files?(@guards, ['lib/my_wonderful_lib.rb']).should be_false }
+    end
+  end
+  
+  describe "#match_file?" do
+    subject { Guard::Watcher.new(%|.*_spec\.rb|) }
+    
+    specify { subject.match_file?('lib/my_wonderful_lib.rb').should be_false }
+    specify { subject.match_file?('guard_rocks_spec.rb').should be_true }
+  end
+  
+end
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