added stale checker test case

test/extra/checking/checkers/test_stale.rb

@@ -0,0 +1,49 @@
+# encoding: utf-8
+
+class Nanoc::Extra::Checking::Checkers::StaleTest < MiniTest::Unit::TestCase
+
+  include Nanoc::TestHelpers
+
+  def checker_class
+    Nanoc::Extra::Checking::Checkers::Stale
+  end
+
+  def calc_issues
+    site = Nanoc::Site.new('.')
+    checker = checker_class.new(site)
+    checker.run
+    checker.issues
+  end
+
+  def test_run_ok
+    with_site do |site|
+      assert Dir['content/*'].empty?
+      assert Dir['output/*'].empty?
+
+      # Empty
+      FileUtils.mkdir_p('output')
+      assert self.calc_issues.empty?
+
+      # One OK file
+      File.write('content/index.html', 'stuff')
+      File.write('output/index.html', 'stuff')
+      assert self.calc_issues.empty?
+    end
+  end
+
+  def test_run_error
+    with_site do |site|
+      assert Dir['content/*'].empty?
+      assert Dir['output/*'].empty?
+
+      File.write('content/index.html', 'stuff')
+      File.write('output/WRONG.html', 'stuff')
+      assert_equal 1, self.calc_issues.count
+      issue = self.calc_issues.to_a[0]
+      assert_equal "file without matching item", issue.description
+      assert_equal "output/WRONG.html", issue.subject
+    end
+  end
+
+end
+