add test to confirm jwks is cached

spec/lib/workos/session_spec.rb

@@ -15,6 +15,52 @@
   end
 
   describe 'initialize' do
+    describe 'JWKS caching' do
+      before do
+        WorkOS::Cache.clear
+      end
+
+      it 'caches and returns JWKS' do
+        expect(Net::HTTP).to receive(:get).once
+        session1 = WorkOS::Session.new(
+          user_management: user_management,
+          client_id: client_id,
+          session_data: session_data,
+          cookie_password: cookie_password,
+        )
+
+        session2 = WorkOS::Session.new(
+          user_management: user_management,
+          client_id: client_id,
+          session_data: session_data,
+          cookie_password: cookie_password,
+        )
+
+        expect(session1.jwks.map(&:export)).to eq(session2.jwks.map(&:export))
+      end
+
+      it 'fetches JWKS from remote when cache is expired' do
+        expect(Net::HTTP).to receive(:get).twice
+        session1 = WorkOS::Session.new(
+          user_management: user_management,
+          client_id: client_id,
+          session_data: session_data,
+          cookie_password: cookie_password,
+        )
+
+        allow(Time).to receive(:now).and_return(Time.now + 301)
+
+        session2 = WorkOS::Session.new(
+          user_management: user_management,
+          client_id: client_id,
+          session_data: session_data,
+          cookie_password: cookie_password,
+        )
+
+        expect(session1.jwks.map(&:export)).to eq(session2.jwks.map(&:export))
+      end
+    end
+
     it 'raises an error if cookie_password is nil or empty' do
       expect do
         WorkOS::Session.new(