add tests

spec/fixtures/files/unlighthouse_report.json

@@ -0,0 +1,18 @@
+[
+  {
+    "path": "/en",
+    "score": 0.78,
+    "performance": 0.64,
+    "accessibility": 0.86,
+    "best-practices": 0.79,
+    "seo": 0.83
+  },
+  {
+    "path": "/en/about-us",
+    "score": 0.78,
+    "performance": 0.63,
+    "accessibility": 0.77,
+    "best-practices": 0.79,
+    "seo": 0.92
+  }
+]

spec/lib/convert_json_to_csv_spec.rb

@@ -0,0 +1,26 @@
+require "rails_helper"
+
+RSpec.describe ConvertJsonToCsv do
+  let(:input_file) { "spec/fixtures/files/unlighthouse_report.json" }
+  let(:output_file) { "spec/fixtures/files/output.csv" }
+
+  after do
+    File.delete(output_file) if File.exist?(output_file)
+  end
+
+  describe ".perform" do
+    it "converts JSON to CSV" do
+      ConvertJsonToCsv.perform(input_file, output_file)
+      csv_content = CSV.read(output_file, headers: true)
+
+      expect(csv_content.headers).to eq(["path", "score", "performance", "accessibility", "best-practices", "seo"])
+
+      expect(csv_content[0]["path"]).to eq("/en")
+      expect(csv_content[0]["score"]).to eq("0.78")
+      expect(csv_content[0]["performance"]).to eq("0.64")
+      expect(csv_content[0]["accessibility"]).to eq("0.86")
+      expect(csv_content[0]["best-practices"]).to eq("0.79")
+      expect(csv_content[0]["seo"]).to eq("0.83")
+    end
+  end
+end