Accept a context in SetSessionMatcher for use with #to

lib/shoulda/action_controller/matchers/set_session_matcher.rb

@@ -19,13 +19,15 @@ def initialize(key)
           @key = key.to_s
         end
 
-        def to(value)
+        def to(value = nil, &block)
           @value = value
+          @value_block = block
           self
         end
 
         def matches?(controller)
           @controller = controller
+          @value = @context.instance_eval(&@value_block) if @value_block
           (assigned_value? && assigned_correct_value?) || cleared_value?
         end
 
@@ -43,6 +45,11 @@ def description
           description
         end
 
+        def in_context(context)
+          @context = context
+          self
+        end
+
         private
 
         def assigned_value?

test/matchers/controller/set_session_matcher_test.rb

@@ -33,6 +33,16 @@ class SetSessionMatcherTest < ActionController::TestCase # :nodoc:
     should "accept assigning false to that variable" do
       assert_accepts set_session(:false_var).to(false), @controller
     end
+
+    should "accept assigning to the same value in the test context" do
+      @expected = 'value'
+      assert_accepts set_session(:var).to { @expected }, @controller
+    end
+
+    should "reject assigning to the another value in the test context" do
+      @expected = 'other'
+      assert_rejects set_session(:var).to { @expected }, @controller
+    end
   end
 
 end