Allow users to define its own set of Cacheable Status Code when using Faraday Middleware Cache

lib/faraday_middleware/response/caching.rb

@@ -86,6 +86,11 @@ def full_key?
       @full_key ||= @options[:full_key]
     end
 
+    def custom_status_codes
+      @custom_status_codes ||= CACHEABLE_STATUS_CODES & Array(@options[:cacheable_status_code]).map(&:to_i)
+      @custom_status_codes.any? ? @custom_status_codes : CACHEABLE_STATUS_CODES
+    end
+
     def cache_on_complete(env)
       key = cache_key(env)
       if (cached_response = cache.read(key))
@@ -101,7 +106,7 @@ def cache_on_complete(env)
     end
 
     def store_response_in_cache(key, response)
-      return unless CACHEABLE_STATUS_CODES.include?(response.status)
+      return unless custom_status_codes.include?(response.status)
 
       if @options[:write_options]
         cache.write(key, response, @options[:write_options])

spec/unit/caching_spec.rb

@@ -40,6 +40,9 @@ def fetch(key)
     response = lambda { |_env|
       [200, { 'Content-Type' => 'text/plain' }, "request:#{request_count += 1}"]
     }
+    not_found = lambda { |_env|
+      [404, { 'Content-Type' => 'text/plain' }, "request:#{request_count += 1}"]
+    }
     broken = lambda { |_env|
       [500, { 'Content-Type' => 'text/plain' }, "request:#{request_count += 1}"]
     }
@@ -54,6 +57,7 @@ def fetch(key)
         stub.get('/broken', &broken)
         stub.get('http://www.site-a.com/test', &response)
         stub.get('http://www.site-b.com/test', &response)
+        stub.get('/not_found', &not_found)
       end
     end
   end
@@ -95,6 +99,40 @@ def fetch(key)
     expect(get('/broken').body).to eq('request:2')
   end
 
+  context ':cacheable_status_code' do
+    let(:options) { { cacheable_status_code: %w[404] } }
+
+    it 'caches requests based on defined cacheable_status_code' do
+      expect(get('/').body).to eq('request:1')
+      expect(get('/not_found').body).to eq('request:2')
+      expect(get('/').body).to eq('request:3')
+      expect(get('/not_found').body).to eq('request:2')
+    end
+
+    context 'with invalid :cacheable_status_code status' do
+      let(:options) { { cacheable_status_code: %w[404,500] } }
+
+      it 'caches requests based on valid defined cacheable_status_code' do
+        expect(get('/not_found').body).to eq('request:1')
+        expect(get('/broken').body).to eq('request:2')
+        expect(get('/not_found').body).to eq('request:1')
+        expect(get('/broken').body).to eq('request:3')
+      end
+    end
+
+    context 'with no valid :cacheable_status_code status' do
+      let(:options) { { cacheable_status_code: %w[500] } }
+      it 'caches requests based on default cacheable_status_code' do
+        expect(get('/').body).to eq('request:1')
+        expect(get('/broken').body).to eq('request:2')
+        expect(get('/').body).to eq('request:1')
+        expect(get('/not_found').body).to eq('request:3')
+        expect(get('/not_found').body).to eq('request:3')
+        expect(get('/broken').body).to eq('request:4')
+      end
+    end
+  end
+
   context ':ignore_params' do
     let(:options) { { ignore_params: %w[utm_source utm_term] } }