Consumer-Provider Example

consumer-provider-example-table.md

Ref	Source Code	Description
C	Consumer.java	The 'consumer' or client application that consumes the demo 'Payment Service' and also listens to a queue
P	PaymentService.java	The provider 'Payment Service' implemented in Spring Boot and using an in-memory data-store
1	ConsumerIntegrationTest.java	An end-to-end integration test of the consumer that needs the real provider to be up and running
KC	payment-service.feature	A 'normal' Karate functional-test that tests the 'contract' of the Payment Service from the perspective of the consumer
2	PaymentServiceContractTest.java	JUnit runner for the above Karate 'contract' test, that depends on the real provider being up and running
KP	payment-service-mock.feature	A 'state-ful' mock (or stub) that fully implements the 'contract' ! Yes, really.
3	PaymentServiceContractUsingMockTest.java	Uses the above 'stub' to run the Payment Service 'contract' test
4	ConsumerUsingMockTest.java	Uses the 'fake' Payment Service 'stub' to run an integration test for the real consumer
KX	payment-service-proxy.feature	Karate can act as a proxy with 'gateway like' capabilities, you can choose to either stub a response or delegate to a remote provider, depending on the incoming request. Think of the 'X' as being able to transform the HTTP request and response payloads as they pass through (and before returning)
5a	ConsumerUsingProxyHttpTest.java	Here Karate is set up to act as an HTTP proxy, the advantage is that the consumer can use the 'real' provider URL, which simplifies configuration, provided that you can configure the consumer to use an HTTP proxy (ideally in a non-invasive fashion)
5b	ConsumerUsingProxyRewriteTest.java	Karate acts as a URL 're-writing' proxy. Here the consumer 'knows' only about the proxy. In this mode (as well as the above 'HTTP proxy' mode which uses the same script file), you can choose to either stub a response - or even forward the incoming HTTP request onto any remote URL you choose.