1 files changed, 24 insertions, 0 deletions
diff --git a/spec/mspec/lib/mspec/matchers/be_ancestor_of.rb b/spec/mspec/lib/mspec/matchers/be_ancestor_of.rb
new file mode 100644
index 0000000000..792c64089a
--- /dev/null
+++ b/spec/mspec/lib/mspec/matchers/be_ancestor_of.rb
@@ -0,0 +1,24 @@
+class BeAncestorOfMatcher
+  def initialize(expected)
+    @expected = expected
+  end
+
+  def matches?(actual)
+    @actual = actual
+    @expected.ancestors.include? @actual
+  end
+
+  def failure_message
+    ["Expected #{@actual}", "to be an ancestor of #{@expected}"]
+  end
+
+  def negative_failure_message
+    ["Expected #{@actual}", "not to be an ancestor of #{@expected}"]
+  end
+end
+
+class Object
+  def be_ancestor_of(expected)
+    BeAncestorOfMatcher.new(expected)
+  end
+end