Add raises! method to GTK::Assert

1 files changed, 13 insertions, 0 deletions

diff --git a/dragon/assert.rb b/dragon/assert.rb
index 47d39ef..0eb8c2a 100644
--- a/dragon/assert.rb
+++ b/dragon/assert.rb
@@ -47,5 +47,18 @@ module GTK
       end
       nil
     end
+
+    def raises! exception_class, message = nil
+      @assertion_performed = true
+      begin
+        yield
+      rescue exception_class
+        return # Success
+      rescue Exception => e
+        raise "Expected #{exception_class.name} to be raised but instead #{e.class.name} was raised\n#{message}"
+      else
+        raise "Expected #{exception_class.name} to be raised but nothing was raised\n#{message}"
+      end
+    end
   end
 end