test/helper.rb in nanoc-3.6.5 vs test/helper.rb in nanoc-3.6.6

@@ -179,11 +179,11 @@
       # Test
       b = binding
       lines.each_slice(2) do |pair|
         actual_out   = eval(pair.first, b)
         expected_out = eval(pair.last.match(/# ?=>(.*)/)[1], b)
-      
+
         assert_equal expected_out, actual_out,
           "Incorrect example:\n#{pair.first}"
       end
     end
   end
@@ -201,9 +201,17 @@
   end
 
   def assert_raises_frozen_error
     error = assert_raises(RuntimeError, TypeError) { yield }
     assert_match(/(^can't modify frozen |^unable to modify frozen object$)/, error.message)
+  end
+
+  def with_env_vars(hash, &block)
+    orig_env_hash = ENV.to_hash
+    hash.each_pair { |k,v| ENV[k] = v }
+    yield
+  ensure
+    orig_env_hash.each_pair { |k,v| ENV[k] = v }
   end
 
 end
 
 class Nanoc::TestCase < MiniTest::Unit::TestCase