Add tests for empty response bodies

README.md

@@ -39,6 +39,29 @@ end
 StatusClient.status
 ```
 
+> **Note:** If your API responds with an empty body (for example, a `204` or a `200` without a payload), do not declare a
+> response `body` structure for that status. Either omit `body` entirely or set `body :default` so Purple::Client skips
+> validation—otherwise the client will raise an error to alert you that the declared structure can never be satisfied.
+
+### Handling empty responses
+
+```ruby
+class PingClient < Purple::Client
+  domain 'https://status.example.com'
+
+  path :ping do
+    # No `body` declaration, because the endpoint always returns HTTP 204 with no payload
+    response :no_content
+    root_method :ping
+  end
+end
+
+# Performs GET https://status.example.com/ping
+# Returns a response object without validating a body schema
+PingClient.ping
+```
+
+
 ### Path with a dynamic parameter
 
 ```ruby

spec/purple/client_spec.rb

@@ -175,6 +175,30 @@ class Unipile::Linkedin::PurpleClient < Purple::Client
       expect(result).to eq(:sent)
       expect(headers['X-API-KEY']).to eq('secret')
     end
+
+    context 'when API responds with an empty body' do
+      it 'raises a helpful error when the body is an empty string' do
+        response = instance_double(Faraday::Response,
+                                   status: 201,
+                                   body: '')
+        allow(connection).to receive(:post).and_return(response)
+
+        expect do
+          described_class.linkedin_invite(provider_id: 1, account_id: 2, message: 'hi', resource: resource)
+        end.to raise_error(/returns empty body, but it is defined in the client/)
+      end
+
+      it 'raises a helpful error when the body is nil' do
+        response = instance_double(Faraday::Response,
+                                   status: 201,
+                                   body: nil)
+        allow(connection).to receive(:post).and_return(response)
+
+        expect do
+          described_class.linkedin_invite(provider_id: 1, account_id: 2, message: 'hi', resource: resource)
+        end.to raise_error(/returns empty body, but it is defined in the client/)
+      end
+    end
   end
 
   describe '.get_user' do