registered diff provider (hapifhir#791)

* registered  provider

* spotless fix

Author: XcrigX

src/main/java/ca/uhn/fhir/jpa/starter/common/StarterJpaConfig.java

@@ -32,6 +32,7 @@
 import ca.uhn.fhir.jpa.packages.IPackageInstallerSvc;
 import ca.uhn.fhir.jpa.packages.PackageInstallationSpec;
 import ca.uhn.fhir.jpa.provider.DaoRegistryResourceSupportedSvc;
+import ca.uhn.fhir.jpa.provider.DiffProvider;
 import ca.uhn.fhir.jpa.provider.IJpaSystemProvider;
 import ca.uhn.fhir.jpa.provider.JpaCapabilityStatementProvider;
 import ca.uhn.fhir.jpa.provider.JpaConformanceProviderDstu2;
@@ -289,7 +290,8 @@ public RestfulServer restfulServer(
 			ThreadSafeResourceDeleterSvc theThreadSafeResourceDeleterSvc,
 			ApplicationContext appContext,
 			Optional<IpsOperationProvider> theIpsOperationProvider,
-			Optional<IImplementationGuideOperationProvider> implementationGuideOperationProvider) {
+			Optional<IImplementationGuideOperationProvider> implementationGuideOperationProvider,
+			DiffProvider diffProvider) {
 		RestfulServer fhirServer = new RestfulServer(fhirSystemDao.getContext());
 
 		List<String> supportedResourceTypes = appProperties.getSupported_resource_types();
@@ -458,6 +460,9 @@ public RestfulServer restfulServer(
 		// Validation
 		repositoryValidatingInterceptor.ifPresent(fhirServer::registerInterceptor);
 
+		// Diff Provider
+		fhirServer.registerProvider(diffProvider);
+
 		// register custom interceptors
 		registerCustomInterceptors(fhirServer, appContext, appProperties.getCustomInterceptorClasses());
 

src/test/java/ca/uhn/fhir/jpa/starter/ExampleServerR4IT.java

@@ -325,6 +325,39 @@ void testActuatorEndpointExists(String endpoint) throws IOException, URISyntaxEx
 
 	}
 
+	@Test
+	void testDiffOperationIsRegistered() {
+		String methodName = "testDiff";
+		ourLog.info("Entering " + methodName + "()...");
+
+		Patient pt = new Patient();
+		pt.setActive(true);
+		pt.getBirthDateElement().setValueAsString("2020-01-01");
+		pt.addIdentifier().setSystem("http://foo").setValue("12345");
+		pt.addName().setFamily(methodName);
+		IIdType id = ourClient.create().resource(pt).execute().getId();
+
+		//now update the patient
+		pt.setId(id);
+		pt.getBirthDateElement().setValueAsString("2025-01-01");
+		ourClient.update().resource(pt).execute();
+
+		//now try a diff
+		Parameters outParams = ourClient.operation().onInstance(id).named("$diff").withNoParameters(Parameters.class).execute();
+		ourLog.trace("Params->\n{}", ourCtx.newJsonParser().setPrettyPrint(true).encodeResourceToString(outParams));
+		boolean foundDobChange = false;
+		//really, if we get a response at all, then the Diff worked, but we'll check the contents here anyway for good measure to see that our change is reflected
+		for(Parameters.ParametersParameterComponent ppc : outParams.getParameter() ) {
+			for(Parameters.ParametersParameterComponent ppc2 : ppc.getPart() ) {
+				if( "Patient.birthDate".equals(ppc2.getValue().toString()) ){
+					foundDobChange = true;
+					break;
+				}
+			}
+		}
+		assertTrue(foundDobChange);
+	}
+
 	@BeforeEach
 	void beforeEach() {
 
@@ -338,4 +371,5 @@ void beforeEach() {
 		//	return activeSubscriptionCount() == 2; // 2 subscription based on mdm-rules.json
 		//});
 	}
+
 }