Handle 429 error (Too Many Requests)

lib/readwise/client.rb

@@ -9,6 +9,15 @@
 module Readwise
   class Client
     class Error < StandardError; end
+    class TooManyRequests < Error
+      def initialize(retry_after)
+        @retry_after = retry_after
+      end
+
+      def message
+        "Try again after #{@retry_after} seconds"
+      end
+    end
 
     BASE_URL = "https://readwise.io/api/v2/"
     V3_BASE_URL = "https://readwise.io/api/v3/"
@@ -302,6 +311,11 @@ def get_readwise_request(url)
         http.request(req)
       end
 
+      if res.code == "429" # Too Many Requests
+        retry_after = Integer(res.fetch("Retry-After"))
+        raise TooManyRequests.new(retry_after)
+      end
+
       raise Error, "Get request failed with status code: #{res.code}" unless res.is_a?(Net::HTTPSuccess)
 
       JSON.parse(res.body)

spec/readwise/client_spec.rb

@@ -311,6 +311,17 @@
         .to raise_error(Readwise::Client::Error, 'Get request failed with status code: 404')
     end
 
+    it 'raises TooManyRequests error on a 429 response' do
+      response = double(code: '429', is_a?: false)
+      allow(response).to receive(:fetch).with("Retry-After").and_return('120')
+      allow(Net::HTTP).to receive(:start).and_return(response)
+
+      expect { subject.send(:get_readwise_request, 'https://example.com') }
+        .to raise_error(Readwise::Client::TooManyRequests) do |error|
+          expect(error.message).to eq('Try again after 120 seconds')
+        end
+    end
+
     it 'raises error on failed POST request' do
       allow(Net::HTTP).to receive(:start).and_return(double(is_a?: false))