Karate Standalone as Mock Server with multiple Feature Files

Question

I try to setup an integration/API test suite with Karate and consider to use Karate Netty for mocking required services. For the test setup the system under test A (a Spring Boot app) is started up completely. The Karate tests are then executed by a Maven test run against this instance.

The service A depends on multiple other services these needs to be mocked away for the tests. To do so my idea was to configure a running Karate Netty standalone instance as HTTP proxy (done by JVM args of the service A).

Now my idea was to create one test feature file: xyz-test.feature
And the required mocks for this file are defined in an associated mock feature file: xyz-mock.feature
(The test scenarios are rather complex and the responses of the external services could vary)

This means for a full test run I need to load up a couple of mock feature files. So:

1. What is the matching strategy for multiple mock feature files? Which scenario wins, so to say.

2. Is there any way to ensure, that the right mock file is used for the associated test file?
   (Clearly I can reconfigure the running standalone instance and advice it to use xyz-mock.feature next.
   But this would stop me from using parallel execution for my API tests, right?)

I already thought about reusing the Correlation-Id which I can send in for each test and then match against this in the mock file (it is also sent to all called services). But:

3. Is there a way to define a global matcher per mock file?

Answer 1

It sounds like you need only one mock file. You could boot 2 on different ports if you wanted, but there is no way to "merge" them into one port - if that is what you were looking for.

In my experience, you will be able to have a single mock take care of all your edge cases. This is because Karate's approach is un-conventional: you pretty much write a stateful server. But by keeping variables in memory and some clever JSON-path, you can simulate CRUD with very few lines of code: https://github.com/intuit/karate/tree/master/karate-netty#background

1. You can use only one at a time, by design

2. Given the above limitation, here's an interesting idea: add something like an extra pathMatches('/__test/reset') scenario that cleans-up your state and sets the Background variables to things like * def cats = []. Now in each feature, just call the special "reset" URL at the start. The good thing is Karate is thread-safe. Another idea as you said is you can maintain two or three different variables and use some logic to "route" based on a header, again very easy IMO. Use a map of maps, e.g:

   • def data = { cats1: {}, cats2: {}, cats3: {} }

And you can get the header, e.g. if it is mode: cats1

* def mode = karate.get('requestHeaders.mode[0]')
* def cats = data[mode]

3. not sure if this answers your question, but if the last Scenario has an "empty" description, it is a "catch all" and can in theory delegate to another server (or mock): https://github.com/intuit/karate/tree/develop/karate-netty#proxy-mode

Your question is a little confusing, so you may have to edit and re-word it if I haven't understood.

EDIT: using multiple mock files should be possible in 1.1.0 onwards: https://github.com/intuit/karate/issues/1566