Add specs for parsing Emoji

spec/helpers/gitlab_markdown_helper_spec.rb

@@ -208,6 +208,40 @@ describe GitlabMarkdownHelper do
         gfm(actual).should match(expected)
       end
     end
+
+    describe "emoji" do
+      it "matches at the start of a string" do
+        gfm(":+1:").should match(/<img/)
+      end
+
+      it "matches at the end of a string" do
+        gfm("This gets a :-1:").should match(/<img/)
+      end
+
+      it "matches with adjacent text" do
+        gfm("+1 (:+1:)").should match(/<img/)
+      end
+
+      it "has a title attribute" do
+        gfm(":-1:").should match(/title=":-1:"/)
+      end
+
+      it "has an alt attribute" do
+        gfm(":-1:").should match(/alt=":-1:"/)
+      end
+
+      it "has an emoji class" do
+        gfm(":+1:").should match('class="emoji"')
+      end
+
+      it "keeps whitespace intact" do
+        gfm("This deserves a :+1: big time.").should match(/deserves a <img.+\/> big time/)
+      end
+
+      it "ignores invalid emoji" do
+        gfm(":invalid-emoji:").should_not match(/<img/)
+      end
+    end
   end
 
   describe "#link_to_gfm" do