add tests for url helper method

test/unit/helpers/url_helper_test.rb

@@ -0,0 +1,20 @@
+require "test_helper"
+
+class UrlHelperTest < ActionView::TestCase
+  context"append_https" do
+    should "return url if it begins with https" do
+      assert_equal "https://www.awesomesite.com", append_https("https://www.awesomesite.com")
+    end
+    should "return empty string if url is empty" do
+      assert_equal "", append_https("")
+    end
+
+    should "return link with https if it does not begin with https" do
+      assert_equal "https://javascript:alert('hello');", append_https("javascript:alert('hello');")
+    end
+
+    should "return empty string if url is nil" do
+      assert_equal "", append_https(nil)
+    end
+  end 
+end