Merge pull request #1886 from Shopify/jloppert/fix-vanity-url-stable-…

…3-45

only replace font urls when content type is not present or it is a text

.changeset/fast-terms-report.md

@@ -0,0 +1,5 @@
+---
+'@shopify/cli-kit': patch
+---
+
+fixes theme preview for new shopify cdn url format

packages/cli-kit/assets/cli-ruby/lib/shopify_cli/theme/dev_server/cdn_fonts.rb

@@ -21,8 +21,14 @@ def call(env)
 
           # Proxy the request, and replace the URLs in the response
           status, headers, body = @app.call(env)
-          body = replace_font_urls(body)
-          [status, headers, body]
+          # Use Rack::Response to get the content type header regardless of case
+          response = Rack::Response.new(nil, status, headers)
+          content_type = response.get_header("Content-Type")
+          if content_type.nil? || content_type == "" || content_type&.start_with?("text/")
+            Rack::Response.new(replace_font_urls(body), status, headers).finish
+          else
+            Rack::Response.new(body, status, headers).finish
+          end
         end
 
         private

packages/cli-kit/assets/cli-ruby/test/shopify-cli/theme/dev_server/cdn_fonts_test.rb

@@ -102,11 +102,28 @@ def test_404_on_missing_cdn_fonts
           assert_equal("Not found", response.body)
         end
 
+        def test_do_not_replace_when_content_type_does_not_match_text
+          CdnFonts.any_instance.expects(:replace_font_urls).never
+          original_input = "https://fonts.shopifycdn.com/font.woff2"
+          response = serve(original_input, path: "/cdn/shop/products/tan-colored-hat-on-monochrome-background.jpg",
+            content_type: "image/jpeg")
+
+          assert_equal(original_input, response.body)
+        end
+
+        def test_replace_when_content_type_does_match_text
+          original_input = "https://fonts.shopifycdn.com/font.woff2"
+          response = serve(original_input, path: "/cdn/shop/products/style.css", content_type: "text/css")
+          response_body = response.body
+          refute_equal(original_input, response_body)
+          assert_equal("/fonts/font.woff2", response_body)
+        end
+
         private
 
-        def serve(response_body = "", path: "/")
+        def serve(response_body = "", path: "/", content_type: "text/html")
           app = lambda do |_env|
-            [200, {}, [response_body]]
+            [200, { "Content-Type" => content_type }, [response_body]]
           end
           stack = CdnFonts.new(app, theme: theme)
           request = Rack::MockRequest.new(stack)