test: CLI:generated integration

Author: steve-redka

spec/rails/diff_spec.rb

@@ -4,4 +4,33 @@
   it "has a version number" do
     expect(Rails::Diff::VERSION).not_to be nil
   end
-end
+  
+  describe ".generated" do
+    before do
+      allow(Rails::Diff).to receive(:system!).and_return(true)
+      allow(Rails::Diff).to receive(:ensure_template_app_exists)
+      allow(Rails::Diff).to receive(:install_app_dependencies)
+      allow(Rails::Diff).to receive(:generated_files).and_return(["file1.rb", "file2.rb"])
+      allow(Rails::Diff).to receive(:diff_with_header).and_return("file1.rb diff:\n===\nDiff content")
+    end
+
+    it "returns the diff for generated files" do
+      result = Rails::Diff.generated("model", "User", no_cache: true)
+      expect(result).to include("file1.rb diff:")
+    end
+  end
+
+  describe Rails::Diff::CLI do
+    describe "#generated" do
+      before do
+        allow(Rails::Diff).to receive(:system!).and_return(true)
+        allow(Rails::Diff).to receive(:generated).and_return("file1.rb diff:\n===\nDiff content")
+      end
+
+      it "runs without error" do
+        cli = Rails::Diff::CLI.new
+        expect { cli.generated("model", "User") }.not_to raise_error
+      end
+    end
+  end
+end