added interrupt class for continue/break statements

When a continue or break statement is executed it pushes an interrupt to a
stack in context. If any non-handled interrupts are present blocks will cease
to execute. The for loop can handle the most recent interrupt in the stack.

test/liquid/tags/break_tag_test.rb

@@ -0,0 +1,16 @@
+require 'test_helper'
+
+class BreakTagTest < Test::Unit::TestCase
+  include Liquid
+
+  # tests that no weird errors are raised if break is called outside of a
+  # block
+  def test_break_with_no_block
+    assigns = {'i' => 1}
+    markup = '{% break %}'
+    expected = ''
+
+    assert_template_result(expected, markup, assigns)
+  end
+
+end

test/liquid/tags/continue_tag_test.rb

@@ -0,0 +1,16 @@
+require 'test_helper'
+
+class ContinueTagTest < Test::Unit::TestCase
+  include Liquid
+
+  # tests that no weird errors are raised if continue is called outside of a
+  # block
+  def test_continue_with_no_block
+    assigns = {}
+    markup = '{% continue %}'
+    expected = ''
+
+    assert_template_result(expected, markup, assigns)
+  end
+
+end

test/liquid/tags/for_tag_test.rb

@@ -168,18 +168,87 @@ HERE
       assert_template_result(expected,markup,assigns)
   end
 
-  def test_break
+  def test_for_with_break
     assigns = {'array' => {'items' => [1,2,3,4,5,6,7,8,9,10]}}
-    markup = '{% for i in array.items %}{{ i }}{% if i > 3 %}{% break %}{% endif %}{% endfor %}'
-    expected = "123"
+
+    markup = '{% for i in array.items %}{% break %}{% endfor %}'
+    expected = ""
     assert_template_result(expected,markup,assigns)
+
+    markup = '{% for i in array.items %}{{ i }}{% break %}{% endfor %}'
+    expected = "1"
+    assert_template_result(expected,markup,assigns)
+
+    markup = '{% for i in array.items %}{% break %}{{ i }}{% endfor %}'
+    expected = ""
+    assert_template_result(expected,markup,assigns)
+
+    markup = '{% for i in array.items %}{{ i }}{% if i > 3 %}{% break %}{% endif %}{% endfor %}'
+    expected = "1234"
+    assert_template_result(expected,markup,assigns)
+
+    # tests to ensure it only breaks out of the local for loop 
+    # and not all of them.
+    assigns = {'array' => [[1,2],[3,4],[5,6]] }
+    markup = '{% for item in array %}' + 
+               '{% for i in item %}' + 
+                 '{% if i == 1 %}' + 
+                   '{% break %}' + 
+                 '{% endif %}' + 
+                 '{{ i }}' + 
+               '{% endfor %}' + 
+             '{% endfor %}'
+    expected = '3456'
+    assert_template_result(expected, markup, assigns)
+
+    # test break does nothing when unreached
+    assigns = {'array' => {'items' => [1,2,3,4,5]}}
+    markup = '{% for i in array.items %}{% if i == 9999 %}{% break %}{% endif %}{{ i }}{% endfor %}'
+    expected = '12345'
+    assert_template_result(expected, markup, assigns)
   end
 
-  def test_continue
+  def test_for_with_continue
     assigns = {'array' => {'items' => [1,2,3,4,5]}}
+
+    markup = '{% for i in array.items %}{% continue %}{% endfor %}'
+    expected = ""
+    assert_template_result(expected,markup,assigns) 
+
+    markup = '{% for i in array.items %}{{ i }}{% continue %}{% endfor %}'
+    expected = "12345"
+    assert_template_result(expected,markup,assigns) 
+
+    markup = '{% for i in array.items %}{% continue %}{{ i }}{% endfor %}'
+    expected = ""
+    assert_template_result(expected,markup,assigns) 
+
+    markup = '{% for i in array.items %}{% if i > 3 %}{% continue %}{% endif %}{{ i }}{% endfor %}'
+    expected = "123"
+    assert_template_result(expected,markup,assigns)
+
     markup = '{% for i in array.items %}{% if i == 3 %}{% continue %}{% else %}{{ i }}{% endif %}{% endfor %}'
     expected = "1245"
     assert_template_result(expected,markup,assigns)
+
+    # tests to ensure it only continues the local for loop and not all of them.
+    assigns = {'array' => [[1,2],[3,4],[5,6]] }
+    markup = '{% for item in array %}' + 
+               '{% for i in item %}' + 
+                 '{% if i == 1 %}' + 
+                   '{% continue %}' + 
+                 '{% endif %}' + 
+                 '{{ i }}' + 
+               '{% endfor %}' + 
+             '{% endfor %}'
+    expected = '23456'
+    assert_template_result(expected, markup, assigns)
+
+    # test continue does nothing when unreached
+    assigns = {'array' => {'items' => [1,2,3,4,5]}}
+    markup = '{% for i in array.items %}{% if i == 9999 %}{% continue %}{% endif %}{{ i }}{% endfor %}'
+    expected = '12345'
+    assert_template_result(expected, markup, assigns)
   end
 
   def test_for_tag_string