Improve and expose the relative_to_base method

lib/listen/directory_record.rb

@@ -148,6 +148,17 @@ def fetch_changes(directories, options = {})
       @changes
     end
 
+    # Converts an absolute path to a path that's relative to the base directory.
+    #
+    # @param [String] path the path to convert
+    #
+    # @return [String] the relative path
+    #
+    def relative_to_base(path)
+      return nil unless path[@directory]
+      path.sub(%r{^#{@directory}#{File::SEPARATOR}?}, '')
+    end
+
     private
 
     # Detects modifications and removals recursively in a directory.
@@ -271,15 +282,5 @@ def insert_path(path)
     def existing_path?(path)
       @paths[File.dirname(path)][File.basename(path)] != nil
     end
-
-    # Converts an absolute path to a path that's relative to the base directory.
-    #
-    # @param [String] path the path to convert
-    #
-    # @return [String] the relative path
-    #
-    def relative_to_base(path)
-      path.sub(%r(^#{@directory}/?/), '')
-    end
   end
 end

spec/listen/directory_record_spec.rb

@@ -55,6 +55,8 @@
   end
 
   describe '#ignored?' do
+    before { subject.stub(:relative_to_base) { |path| path } }
+
     it 'tests paths relative to the base directory' do
       subject.should_receive(:relative_to_base).with('file.txt')
       subject.ignored?('file.txt')
@@ -85,6 +87,8 @@
   end
 
   describe '#filterd?' do
+    before { subject.stub(:relative_to_base) { |path| path } }
+
     context 'when no filtering pattrens are set' do
       it 'returns true for any path' do
         subject.filtered?('file.txt').should be_true
@@ -180,6 +184,17 @@
     end
   end
 
+  describe '#relative_to_base' do
+    it 'removes the path of the base-directory from the passed path' do
+      path = 'dir/to/app/file.rb'
+      subject.relative_to_base(File.join(base_directory, path)).should eq path
+    end
+
+    it 'returns nil when the passed path is not inside the base-directory' do
+      subject.relative_to_base('/tmp/some_random_path').should be_nil
+    end
+  end
+
   describe '#fetch_changes' do
     context 'with single file changes' do
       context 'when a file is created' do