Resolve "Lazy load images on the Frontend"

2 files changed, 21 insertions, 2 deletions

diff --git a/spec/lib/banzai/filter/gollum_tags_filter_spec.rb b/spec/lib/banzai/filter/gollum_tags_filter_spec.rb
index 082c0d4dd0d..cbb2808c6bb 100644
--- a/spec/lib/banzai/filter/gollum_tags_filter_spec.rb
+++ b/spec/lib/banzai/filter/gollum_tags_filter_spec.rb
@@ -22,7 +22,7 @@ describe Banzai::Filter::GollumTagsFilter, lib: true do
       tag = '[[images/image.jpg]]'
       doc = filter("See #{tag}", project_wiki: project_wiki)
 
-      expect(doc.at_css('img')['src']).to eq "#{project_wiki.wiki_base_path}/images/image.jpg"
+      expect(doc.at_css('img')['data-src']).to eq "#{project_wiki.wiki_base_path}/images/image.jpg"
     end
 
     it 'does not creates img tag if image does not exist' do
@@ -40,7 +40,7 @@ describe Banzai::Filter::GollumTagsFilter, lib: true do
       tag = '[[http://example.com/image.jpg]]'
       doc = filter("See #{tag}", project_wiki: project_wiki)
 
-      expect(doc.at_css('img')['src']).to eq "http://example.com/image.jpg"
+      expect(doc.at_css('img')['data-src']).to eq "http://example.com/image.jpg"
     end
 
     it 'does not creates img tag for invalid URL' do
diff --git a/spec/lib/banzai/filter/image_lazy_load_filter_spec.rb b/spec/lib/banzai/filter/image_lazy_load_filter_spec.rb
new file mode 100644
index 00000000000..c19de7b784a
--- /dev/null
+++ b/spec/lib/banzai/filter/image_lazy_load_filter_spec.rb
@@ -0,0 +1,19 @@
+require 'spec_helper'
+
+describe Banzai::Filter::ImageLazyLoadFilter, lib: true do
+  include FilterSpecHelper
+
+  def image(path)
+    %(<img src="#{path}" />)
+  end
+
+  it 'transforms the image src to a data-src' do
+    doc = filter(image('/uploads/e90decf88d8f96fe9e1389afc2e4a91f/test.jpg'))
+    expect(doc.at_css('img')['data-src']).to eq '/uploads/e90decf88d8f96fe9e1389afc2e4a91f/test.jpg'
+  end
+
+  it 'works with external images' do
+    doc = filter(image('https://i.imgur.com/DfssX9C.jpg'))
+    expect(doc.at_css('img')['data-src']).to eq 'https://i.imgur.com/DfssX9C.jpg'
+  end
+end