Package com.shri.restinpeace.mock

Class MockRestServerExtension

java.lang.Object

com.shri.restinpeace.mock.MockRestServerExtension

All Implemented Interfaces:

org.junit.jupiter.api.extension.AfterAllCallback, org.junit.jupiter.api.extension.BeforeAllCallback, org.junit.jupiter.api.extension.BeforeEachCallback, org.junit.jupiter.api.extension.Extension, org.junit.jupiter.api.extension.ParameterResolver, org.junit.jupiter.api.extension.TestInstantiationAwareExtension

public final class MockRestServerExtension
extends Object
implements org.junit.jupiter.api.extension.BeforeAllCallback, org.junit.jupiter.api.extension.AfterAllCallback, org.junit.jupiter.api.extension.BeforeEachCallback, org.junit.jupiter.api.extension.ParameterResolver

A JUnit 5 extension that starts one MockRestServer for a whole test class and resets it before each test - register it with @ExtendWith and receive the server as a test (or @BeforeEach) method parameter, instead of wiring up @BeforeAll/@AfterAll/@BeforeEach boilerplate by hand.

 @ExtendWith(MockRestServerExtension.class)
 class OrderServiceTest {

     private OrderApi api;

     @BeforeEach
     void setUp(MockRestServer server) {
         api = RIP.getClient(OrderApi.class, server.baseUrl());
     }

     @Test
     void placesAnOrder(MockRestServer server) {
         server.on(HTTPMethod.GET, "/orders/{id}", MockResponse.ok("{}"));
         ...
     }
 }
 

Because the server (and so its MockRestServer.baseUrl()) is the same object for every test method in the class, a @RestClient built from it - like api above - can be built once in @BeforeEach instead of needing the fresh base URL a new server per test would otherwise force.

Registration: the server starts in a BeforeAllCallback, which JUnit only invokes for an extension it can discover before any test instance exists - that means @ExtendWith(MockRestServerExtension.class) on the class (as above), or a static field annotated @RegisterExtension. Registering it on a non-static @RegisterExtension field silently skips server startup and shutdown, since JUnit can't read an instance field before an instance exists - prefer @ExtendWith unless a test specifically needs to keep a reference to the extension itself via getServer().

Isolation: every test method in the class shares the same server - MockRestServer.reset() between tests clears routes, queued responses, and recorded requests, but the server itself, and everything built against its base URL, is not safe for concurrent use. Don't combine this extension with parallel test execution within the same class.

Requires junit-jupiter-api on the consumer's own test classpath - a provided-scope dependency of this library, not a transitive runtime one, so using this class is opt-in and costs a consumer who doesn't nothing.

Unhit-route reporting: reportUnhitRoutes() opts into printing every route (MockRestServer.getUnhitRoutes()) still unhit when the test class finishes - a route left registered after the code path that used to exercise it was removed otherwise causes no failure at all. This only works with the static @RegisterExtension field style, since @ExtendWith(MockRestServerExtension.class) has JUnit construct the extension itself via the no-arg constructor, with no way to call reportUnhitRoutes() first:

 class OrderServiceTest {

     @RegisterExtension
     static MockRestServerExtension extension = new MockRestServerExtension().reportUnhitRoutes();

     @Test
     void placesAnOrder(MockRestServer server) {
         server.on(HTTPMethod.GET, "/orders/{id}", MockResponse.ok("{}"));
         // ... a test that never actually calls /orders/{id} prints a warning at afterAll
     }
 }
 

Nested Class Summary

Nested classes/interfaces inherited from interface org.junit.jupiter.api.extension.TestInstantiationAwareExtension

org.junit.jupiter.api.extension.TestInstantiationAwareExtension.ExtensionContextScope

Constructor Summary

Constructors

Constructor	Description
MockRestServerExtension()	Creates the extension - register it via @ExtendWith, it needs no arguments.

Method Summary

Modifier and Type	Method	Description
void	afterAll(org.junit.jupiter.api.extension.ExtensionContext context)
void	beforeAll(org.junit.jupiter.api.extension.ExtensionContext context)
void	beforeEach(org.junit.jupiter.api.extension.ExtensionContext context)
MockRestServer	getServer()	Returns the server for the current test class - only meaningful once beforeAll has run.
MockRestServerExtension	reportUnhitRoutes()	Opts into printing every unhit route to System.err at afterAll - see this class's own javadoc for why this only takes effect with the static @RegisterExtension field style.
Object	resolveParameter(org.junit.jupiter.api.extension.ParameterContext parameterContext, org.junit.jupiter.api.extension.ExtensionContext extensionContext)
boolean	supportsParameter(org.junit.jupiter.api.extension.ParameterContext parameterContext, org.junit.jupiter.api.extension.ExtensionContext extensionContext)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.junit.jupiter.api.extension.TestInstantiationAwareExtension

getTestInstantiationExtensionContextScope

Constructor Details

MockRestServerExtension

public MockRestServerExtension()

Creates the extension - register it via @ExtendWith, it needs no arguments.

Method Details

reportUnhitRoutes

public MockRestServerExtension reportUnhitRoutes()

Opts into printing every unhit route to System.err at afterAll - see this class's own javadoc for why this only takes effect with the static @RegisterExtension field style. Purely a diagnostic: it never fails the test class, whether or not any route is left unhit.

Returns:

this extension, for chaining onto the @RegisterExtension field assignment

getServer

public MockRestServer getServer()

Returns the server for the current test class - only meaningful once beforeAll has run. Prefer receiving MockRestServer as a parameter (see the class javadoc) over calling this directly; it exists for the static @RegisterExtension field registration style, where no test instance is available to resolve a parameter against (e.g. a static @BeforeAll method).

Returns:

this class's server

beforeAll

public void beforeAll(org.junit.jupiter.api.extension.ExtensionContext context)

Specified by:

beforeAll in interface org.junit.jupiter.api.extension.BeforeAllCallback

beforeEach

public void beforeEach(org.junit.jupiter.api.extension.ExtensionContext context)

Specified by:

beforeEach in interface org.junit.jupiter.api.extension.BeforeEachCallback

afterAll

public void afterAll(org.junit.jupiter.api.extension.ExtensionContext context)

Specified by:

afterAll in interface org.junit.jupiter.api.extension.AfterAllCallback

supportsParameter

public boolean supportsParameter(org.junit.jupiter.api.extension.ParameterContext parameterContext,
 org.junit.jupiter.api.extension.ExtensionContext extensionContext)
                          throws org.junit.jupiter.api.extension.ParameterResolutionException

Specified by:

supportsParameter in interface org.junit.jupiter.api.extension.ParameterResolver

Throws:

org.junit.jupiter.api.extension.ParameterResolutionException

resolveParameter

public Object resolveParameter(org.junit.jupiter.api.extension.ParameterContext parameterContext,
 org.junit.jupiter.api.extension.ExtensionContext extensionContext)
                        throws org.junit.jupiter.api.extension.ParameterResolutionException

Specified by:

resolveParameter in interface org.junit.jupiter.api.extension.ParameterResolver

Throws:

org.junit.jupiter.api.extension.ParameterResolutionException