normalize fa cdn hosts to avoid redownloading files

spec/jobs/domain/fa/job/scan_post_job_spec.rb

@@ -219,4 +219,81 @@ describe Domain::Fa::Job::ScanPostJob do
       expect(post.state).to eq("removed")
     end
   end
+
+  describe "#uri_same_with_normalized_facdn_host?" do
+    let(:client_mock_config) { [] }
+
+    shared_examples "has result" do |result|
+      it "is #{result.to_s}, both have schema" do
+        url1 = "https://#{host1}#{path1}"
+        url2 = "https://#{host2}#{path2}"
+        expect(
+          described_class.uri_same_with_normalized_facdn_host?(url1, url2),
+        ).to eq(result)
+      end
+
+      it "is #{result.to_s}, both missing schema" do
+        url1 = "//#{host1}#{path1}"
+        url2 = "//#{host2}#{path2}"
+        expect(
+          described_class.uri_same_with_normalized_facdn_host?(url1, url2),
+        ).to eq(result)
+      end
+
+      it "is #{result.to_s}, one has schema" do
+        url1 = "https://#{host1}#{path1}"
+        url2 = "//#{host2}#{path2}"
+        expect(
+          described_class.uri_same_with_normalized_facdn_host?(url1, url2),
+        ).to eq(result)
+      end
+    end
+
+    shared_context "host: different cdn hosts" do
+      let(:host1) { "d.facdn.net" }
+      let(:host2) { "d.furaffinity.net" }
+    end
+
+    shared_context "host: both hosts are d.facdn.net" do
+      let(:host1) { "d.facdn.net" }
+      let(:host2) { "d.facdn.net" }
+    end
+
+    shared_context "host: both hosts are d.furaffinity.net" do
+      let(:host1) { "d.furaffinity.net" }
+      let(:host2) { "d.furaffinity.net" }
+    end
+
+    shared_context "host: one domain is not a cdn" do
+      let(:host1) { "d.facdn.net" }
+      let(:host2) { "example.com" }
+    end
+
+    shared_context "paths: are the same" do
+      let(:path1) { "/art/user/1234567890/image.jpg" }
+      let(:path2) { "/art/user/1234567890/image.jpg" }
+    end
+
+    shared_context "paths: are different" do
+      let(:path1) { "/art/user/1234567890/image.jpg" }
+      let(:path2) { "/art/user/1234567890/some_other_image.jpg" }
+    end
+
+    [
+      ["host: different cdn hosts", "paths: are the same", true],
+      ["host: both hosts are d.facdn.net", "paths: are the same", true],
+      ["host: both hosts are d.furaffinity.net", "paths: are the same", true],
+      ["host: one domain is not a cdn", "paths: are the same", false],
+      ["host: different cdn hosts", "paths: are different", false],
+      ["host: both hosts are d.facdn.net", "paths: are different", false],
+      ["host: both hosts are d.furaffinity.net", "paths: are different", false],
+      ["host: one domain is not a cdn", "paths: are different", false],
+    ].each do |host_context, path_context, result|
+      context "#{host_context} and #{path_context}" do
+        include_context host_context
+        include_context path_context
+        include_examples "has result", result
+      end
+    end
+  end
 end