Make --out to create parent directories

Fix rubocop#1389.

.rubocop_todo.yml

@@ -1,5 +1,5 @@
 # This configuration was generated by `rubocop --auto-gen-config`
-# on 2014-10-12 09:19:35 +0200 using RuboCop version 0.26.1.
+# on 2014-10-17 19:20:51 +0900 using RuboCop version 0.26.1.
 # The point is for the user to remove these configuration records
 # one by one as the offenses are removed from the code base.
 # Note that changes in the inspected code, or installation of new
@@ -18,7 +18,7 @@ Metrics/ClassLength:
 Metrics/CyclomaticComplexity:
   Max: 10
 
-# Offense count: 135
+# Offense count: 136
 # Configuration parameters: CountComments.
 Metrics/MethodLength:
   Max: 21

CHANGELOG.md

@@ -16,6 +16,7 @@
 * [#1350](https://github.com/bbatsov/rubocop/issues/1350): Guard against `Blocks` cop introducing syntax errors in auto-correct. ([@jonas054][])
 * [#1374](https://github.com/bbatsov/rubocop/issues/1374): To eliminate interference, auto-correction is now done by one cop at a time, with saving and re-parsing inbetween. ([@jonas054][])
 * [#1388](https://github.com/bbatsov/rubocop/issues/1388): Fix a false positive in `FormatString`. ([@bbatsov][])
+* [#1389](https://github.com/bbatsov/rubocop/issues/1389): Make `--out` to create parent directories. ([@yous][])
 
 ## 0.26.1 (18/09/2014)
 

lib/rubocop/formatter/formatter_set.rb

@@ -1,5 +1,7 @@
 # encoding: utf-8
 
+require 'fileutils'
+
 module RuboCop
   module Formatter
     # This is a collection of formatters. A FormatterSet can hold multiple
@@ -37,7 +39,13 @@ def add_formatter(formatter_type, output_path = nil)
                             builtin_formatter_class(formatter_type)
                           end
 
-        output = output_path ? File.open(output_path, 'w') : $stdout
+        if output_path
+          dir_path = File.dirname(output_path)
+          FileUtils.mkdir_p(dir_path) unless File.exist?(dir_path)
+          output = File.open(output_path, 'w')
+        else
+          output = $stdout
+        end
 
         self << formatter_class.new(output)
       end

spec/rubocop/formatter/formatter_set_spec.rb

@@ -62,6 +62,15 @@ module Formatter
             expect(formatter_set.first.output.class).to eq(File)
             expect(formatter_set.first.output.path).to eq(output_path)
           end
+
+          it "creates parent directories if they don't exist" do
+            Dir.mktmpdir do |tmpdir|
+              output_path = File.join(tmpdir, 'path/does/not/exist')
+              formatter_set.add_formatter('simple', output_path)
+              expect(formatter_set.first.output.class).to eq(File)
+              expect(formatter_set.first.output.path).to eq(output_path)
+            end
+          end
         end
       end