improved error handling

Mailtrap sending client used to raise `server error` on 403.

lib/mailtrap/sending.rb

@@ -17,6 +17,21 @@ def initialize(messages)
       end
     end
 
+    # AuthorizationError is raised when invalid token is used.
     class AuthorizationError < Error; end
+
+    # MailSizeError is raised when mail is too large.
+    class MailSizeError < Error; end
+
+    # RateLimitError is raised when client performing too many requests.
+    class RateLimitError < Error; end
+
+    # RejectionError is raised when server refuses to process the request. Use
+    # error message to debug the problem.
+    #
+    # *Some* possible reasons:
+    #   * Account is banned
+    #   * Domain is not verified
+    class RejectionError < Error; end
   end
 end

lib/mailtrap/sending/client.rb

@@ -44,15 +44,25 @@ def post_request(path, body)
       end
 
       def handle_response(response)
-        case response.code
-        when '200'
+        case response
+        when Net::HTTPOK
           json_response(response.body)
-        when '400'
+        when Net::HTTPBadRequest
           raise Mailtrap::Sending::Error, json_response(response.body)[:errors]
-        when '401'
+        when Net::HTTPUnauthorized
           raise Mailtrap::Sending::AuthorizationError, json_response(response.body)[:errors]
-        else
+        when Net::HTTPForbidden
+          raise Mailtrap::Sending::RejectionError, json_response(response.body)[:errors]
+        when Net::HTTPPayloadTooLarge
+          raise Mailtrap::Sending::MailSizeError, ['message too large']
+        when Net::HTTPTooManyRequests
+          raise Mailtrap::Sending::RateLimitError, ['too many requests']
+        when Net::HTTPClientError
+          raise Mailtrap::Sending::Error, ['client error']
+        when Net::HTTPServerError
           raise Mailtrap::Sending::Error, ['server error']
+        else
+          raise Mailtrap::Sending::Error, ["unexpected status code=#{response.code}"]
         end
       end
 

spec/mailtrap/sending/client_spec.rb

@@ -108,4 +108,71 @@
       end
     end
   end
+
+  describe 'errors' do
+    let(:mail) do
+      Mailtrap::Mail::Base.new(
+        from: { email: 'from@example.com' },
+        to: [{ email: 'to@example.com' }],
+        subject: 'Test',
+        text: 'Test'
+      )
+    end
+
+    subject { client.send(mail) }
+
+    def stub_api_send(status, body=nil)
+      stub = stub_request(:post, /\/api\/send/).to_return(status: status, body: body)
+      yield
+      expect(stub).to have_been_requested
+    end
+
+    it 'handles 400' do
+      stub_api_send 400, '{"errors":["error"]}' do
+        expect { subject }.to raise_error(Mailtrap::Sending::Error)
+      end
+    end
+
+    it 'handles 401' do
+      stub_api_send 401, '{"errors":["Unauthorized"]}' do
+        expect { subject }.to raise_error(Mailtrap::Sending::AuthorizationError)
+      end
+    end
+
+    it 'handles 403' do
+      stub_api_send 403, '{"errors":["Account is banned"]}' do
+        expect { subject }.to raise_error(Mailtrap::Sending::RejectionError)
+      end
+    end
+
+    it 'handles 413' do
+      stub_api_send 413 do
+        expect { subject }.to raise_error(Mailtrap::Sending::MailSizeError)
+      end
+    end
+
+    it 'handles 429' do
+      stub_api_send 429 do
+        expect { subject }.to raise_error(Mailtrap::Sending::RateLimitError)
+      end
+    end
+
+    it 'handles generic client errors' do
+      stub_api_send 418, '🫖' do
+        expect { subject }.to raise_error(Mailtrap::Sending::Error, 'client error')
+      end
+    end
+
+    it 'handles server errors' do
+      stub_api_send 504, '🫖' do
+        expect { subject }.to raise_error(Mailtrap::Sending::Error, 'server error')
+      end
+    end
+
+    it 'handles unexpected response status code' do
+      stub_api_send 307 do
+        expect { subject }.to raise_error(Mailtrap::Sending::Error, 'unexpected status code=307')
+      end
+    end
+  end
 end

spec/spec_helper.rb

@@ -3,6 +3,7 @@
 require 'mail'
 require 'mailtrap'
 require 'rspec/its'
+require 'webmock/rspec'
 require 'vcr'
 
 VCR.configure do |config|