1 files changed, 86 insertions, 0 deletions
diff --git a/rake_tasks/diff.rake b/rake_tasks/diff.rake
new file mode 100644
index 0000000..9cd67b9
--- /dev/null
+++ b/rake_tasks/diff.rake
@@ -0,0 +1,86 @@
+# A simple differ using svn. Handles externals.
+class Differ < Hash
+  
+  def initialize path
+    @path = path
+    super 0
+  end
+  
+  def count key, value
+    self[key] += value
+    value
+  end
+  
+  FORMAT = '  %-30s %8d lines, %3d changes in %2d files'
+  
+  def scan(path = @path)
+    Dir.chdir path do
+      system 'svn diff > diff'
+      if File.size? 'diff'
+        puts FORMAT %
+          [
+            path,
+            count(:LOC, `wc -l diff`.to_i),
+            count(:changes, `grep ^@@ diff | wc -l`.to_i),
+            count(:files, `grep ^Index diff | wc -l`.to_i),
+          ]
+      else
+        rm 'diff'
+      end
+    end
+  end
+  
+  def scan_with_externals(path = @path)
+    scan path
+    `svn status`.scan(/^X\s*(.*)/) do |external,|
+      scan external
+    end
+  end
+  
+  def clean(path = @path)
+    Dir.chdir path do
+      rm 'diff' if File.exist? 'diff'
+    end
+  end
+  
+  def clean_with_externals(path = @path)
+    clean path
+    `svn status`.scan(/^X\s*(.*)/) do |external,|
+      clean external
+    end
+  end
+  
+  def differences?
+    self[:LOC] > 0
+  end
+  
+  def inspect
+    FORMAT %
+      [ 'Total', self[:LOC], self[:changes], self[:files] ]
+  end
+  
+end
+
+namespace :diff do
+  
+  desc 'Make a diff and print a summary'
+  task :summary do
+    differ = Differ.new '.'
+    differ.scan_with_externals
+    if differ.empty?
+      puts 'No differences found.'
+    else
+      p differ
+    end
+  end
+  
+  desc 'Remove all diffs'
+  task :clean do
+    differ = Differ.new '.'
+    differ.clean_with_externals
+  end
+  
+end
+
+desc 'Make a diff and print a summary'
+task :diff => 'diff:summary'