Allow Giphy links to be used and not from Cloudinary (#927)

* Test for giphy images

* Allow giphy images to be used as-is

app/labor/markdown_parser.rb

@@ -59,12 +59,18 @@ class MarkdownParser
   end
 
   def prefix_all_images(html, width = 880)
+    # wrap with Cloudinary or allow if from giphy or githubusercontent.com
     doc = Nokogiri::HTML.fragment(html)
     doc.css("img").each do |img|
-      if img.attr("src") && check_image_rehost_whitelist(img.attr("src"))
-        src = img.attr("src")
-        img["src"] = img_of_size(src, width)
-      end
+      src = img.attr("src")
+      next unless src
+      # allow image to render as-is
+      next if whitelisted_image_host?(src)
+      img["src"] = if giphy_img?(src)
+                     src.gsub("https://media.", "https://i.")
+                   else
+                     img_of_size(src, width)
+                   end
     end
     doc.to_html
   end
@@ -99,9 +105,19 @@ class MarkdownParser
     end
   end
 
-  def check_image_rehost_whitelist(src)
+  def whitelisted_image_host?(src)
     # GitHub camo image won't parse but should be safe to host direct
-    !src.start_with?("https://camo.githubusercontent.com/")
+    src.start_with?("https://camo.githubusercontent.com/")
+  end
+
+  def giphy_img?(source)
+    uri = URI.parse(source)
+    return false if uri.scheme != "https"
+    return false if uri.userinfo || uri.fragment || uri.query
+    return false if uri.host != "media.giphy.com" && uri.host != "i.giphy.com"
+    return false if uri.port != 443 # I think it has to be this if its https?
+
+    uri.path.ends_with?(".gif")
   end
 
   def remove_nested_linebreak_in_list(html)

spec/labor/markdown_parser_spec.rb

@@ -77,10 +77,42 @@ RSpec.describe MarkdownParser do
     end
   end
 
+  context "when using gifs from Giphy as images" do
+    let(:giphy_markdown_texts) do
+      %w(
+        ![source](https://media.giphy.com/media/3ow0TN2M8TH2aAn67F/giphy.gif)
+        ![social](https://media.giphy.com/media/3ow0TN2M8TH2aAn67F/giphy.gif)
+        ![small](https://media.giphy.com/media/3ow0TN2M8TH2aAn67F/200w_d.gif)
+      )
+    end
+
+    it "does not wrap giphy images with Cloudinary" do
+      giphy_markdown_texts.each do |body_markdown|
+        html = Nokogiri::HTML(generate_and_parse_markdown(body_markdown))
+        img_src = html.search("img")[0]["src"]
+        expect(img_src).not_to include("https://res.cloudinary.com")
+      end
+    end
+
+    it "uses the raw gif from i.giphy.com" do
+      giphy_markdown_texts.each do |body_markdown|
+        html = Nokogiri::HTML(generate_and_parse_markdown(body_markdown))
+        img_src = html.search("img")[0]["src"]
+        expect(img_src).to start_with("https://i.giphy.com")
+      end
+    end
+  end
+
   context "when an image is used" do
+    let(:markdown_with_img) { "![](https://image.com/image.jpg)" }
+
     it "wraps image in link" do
-      inline_code = "![](https://image.com/image.jpg)"
-      expect(generate_and_parse_markdown(inline_code)).to include("<a")
+      expect(generate_and_parse_markdown(markdown_with_img)).to include("<a")
+    end
+
+    it "wraps the image with Cloudinary" do
+      expect(generate_and_parse_markdown(markdown_with_img)).
+        to include("https://res.cloudinary.com")
     end
   end