Feat/support head metadata (#6406)

* Added support for HTTP HEAD

* Renamed file to issue number and added issue number

* Moved to 7.6

* Adjusted to new init method

* Corrected error messages

* Moved to 7.8.0 as it isn't urgent

* Moved to 8.2.0

* Added HEAD test for stu3

* Added HEAD test

* Adjusted according to review comments

* Spotless formatting

* Update MetadataCapabilityStatementDstu3Test.java

* Update MetadataCapabilityStatementDstu3Test.java

---------

Co-authored-by: James Agnew <[email protected]>

Author: jkiddo

hapi-fhir-docs/src/main/resources/ca/uhn/hapi/fhir/changelog/8_2_0/6152-add-support-for-head-request.yaml

@@ -0,0 +1,4 @@
+---
+type: add
+issue: 6152
+title: "Added the option to do HTTP HEAD requests against /metadata. Thanks to Jens Villadsen (@jkiddo) for the contribution!"

hapi-fhir-server/src/main/java/ca/uhn/fhir/rest/server/method/ConformanceMethodBinding.java

@@ -220,11 +220,11 @@ public MethodMatchEnum incomingServerRequestMatchesMethod(RequestDetails theRequ
 		}
 
 		if ("metadata".equals(theRequest.getOperation())) {
-			if (theRequest.getRequestType() == RequestTypeEnum.GET) {
+			if (theRequest.getRequestType() == RequestTypeEnum.GET
+					|| theRequest.getRequestType() == RequestTypeEnum.HEAD) {
 				return MethodMatchEnum.EXACT;
 			}
-			throw new MethodNotAllowedException(
-					Msg.code(388) + "/metadata request must use HTTP GET", RequestTypeEnum.GET);
+			throw new MethodNotAllowedException(Msg.code(388) + "/metadata request must use HTTP GET or HTTP HEAD");
 		}
 
 		return MethodMatchEnum.NONE;

hapi-fhir-server/src/test/java/ca/uhn/fhir/rest/server/method/ConformanceMethodBindingTest.java

@@ -3,6 +3,7 @@
 import ca.uhn.fhir.context.FhirContext;
 import ca.uhn.fhir.rest.annotation.Metadata;
 import ca.uhn.fhir.rest.api.Constants;
+import ca.uhn.fhir.rest.api.RequestTypeEnum;
 import ca.uhn.fhir.rest.api.server.IRestfulServer;
 import ca.uhn.fhir.rest.api.server.RequestDetails;
 import ca.uhn.fhir.rest.server.servlet.ServletRequestDetails;
@@ -12,12 +13,15 @@
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.ExtendWith;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.EnumSource;
 import org.mockito.Answers;
 import org.mockito.Mock;
 import org.mockito.junit.jupiter.MockitoExtension;
 
 import java.lang.reflect.Method;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.Mockito.RETURNS_DEEP_STUBS;
 import static org.mockito.Mockito.mock;
@@ -106,6 +110,21 @@ public void invokeServerNotCached_ClientControlled() throws NoSuchMethodExceptio
 		verify(provider, times(2)).getServerConformance(any(), any());
 	}
 
+
+	@ParameterizedTest
+	@EnumSource(
+		value = RequestTypeEnum.class,
+		names = {"GET", "HEAD"})
+	public void invokeServer_metadata(RequestTypeEnum requestTypeEnum) throws NoSuchMethodException {
+		init(new TestResourceProvider());
+
+		RequestDetails requestDetails = mySrd;
+		when(requestDetails.getOperation()).thenReturn("metadata");
+		when(requestDetails.getRequestType()).thenReturn(requestTypeEnum);
+		assertEquals(conformanceMethodBinding.incomingServerRequestMatchesMethod(requestDetails), MethodMatchEnum.EXACT);
+
+	}
+
 	@SuppressWarnings("unused")
 	static class TestResourceProvider {
 

hapi-fhir-structures-dstu3/src/test/java/ca/uhn/fhir/rest/server/MetadataCapabilityStatementDstu3Test.java

@@ -18,6 +18,7 @@
 import org.apache.commons.io.IOUtils;
 import org.apache.http.client.methods.CloseableHttpResponse;
 import org.apache.http.client.methods.HttpGet;
+import org.apache.http.client.methods.HttpHead;
 import org.apache.http.client.methods.HttpPost;
 import org.apache.http.client.methods.HttpRequestBase;
 import org.hl7.fhir.dstu3.hapi.rest.server.ServerCapabilityStatementProvider;
@@ -96,7 +97,7 @@ public void testHttpMethods() throws Exception {
 			status = ourClient.execute(httpPost);
 			output = IOUtils.toString(status.getEntity().getContent(), StandardCharsets.UTF_8);
 			assertEquals(405, status.getStatusLine().getStatusCode());
-			assertEquals("<OperationOutcome xmlns=\"http://hl7.org/fhir\"><issue><severity value=\"error\"/><code value=\"processing\"/><diagnostics value=\"" + Msg.code(388) + "/metadata request must use HTTP GET\"/></issue></OperationOutcome>", output);
+			assertEquals("<OperationOutcome xmlns=\"http://hl7.org/fhir\"><issue><severity value=\"error\"/><code value=\"processing\"/><diagnostics value=\"" + Msg.code(388) + "/metadata request must use HTTP GET or HTTP HEAD\"/></issue></OperationOutcome>", output);
 		} finally {
 			IOUtils.closeQuietly(status.getEntity().getContent());
 		}
@@ -133,6 +134,15 @@ public void testResponseContainsBaseUrl() throws Exception {
 		}
 	}
 
+	@Test
+	public void testHeadElements() throws Exception {
+
+		HttpRequestBase httpHead = new HttpHead(ourServer.getBaseUrl() + "/metadata?_elements=fhirVersion&_pretty=true");
+		CloseableHttpResponse status = ourClient.execute(httpHead);
+		status.getAllHeaders();
+		assertEquals(200, status.getStatusLine().getStatusCode());
+	}
+
 	@Test
 	public void testResponseContainsBaseUrlFixed() throws Exception {
 		ourServer.setServerAddressStrategy(new HardcodedServerAddressStrategy("http://foo/bar"));

hapi-fhir-structures-dstu3/src/test/java/ca/uhn/fhir/rest/server/MetadataConformanceDstu3Test.java

@@ -17,6 +17,7 @@
 import org.apache.commons.io.IOUtils;
 import org.apache.http.client.methods.CloseableHttpResponse;
 import org.apache.http.client.methods.HttpGet;
+import org.apache.http.client.methods.HttpHead;
 import org.apache.http.client.methods.HttpOptions;
 import org.apache.http.client.methods.HttpPost;
 import org.apache.http.client.methods.HttpRequestBase;
@@ -29,6 +30,7 @@
 import java.util.List;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.jupiter.api.Assertions.assertNull;
 
 public class MetadataConformanceDstu3Test {
 
@@ -121,7 +123,13 @@ public void testHttpMethods() throws Exception {
 		try (CloseableHttpResponse status = ourClient.execute(httpOperation)) {
 			output = IOUtils.toString(status.getEntity().getContent(), StandardCharsets.UTF_8);
 			assertEquals(405, status.getStatusLine().getStatusCode());
-			assertEquals("<OperationOutcome xmlns=\"http://hl7.org/fhir\"><issue><severity value=\"error\"/><code value=\"processing\"/><diagnostics value=\"" + Msg.code(388) + "/metadata request must use HTTP GET\"/></issue></OperationOutcome>", output);
+			assertEquals("<OperationOutcome xmlns=\"http://hl7.org/fhir\"><issue><severity value=\"error\"/><code value=\"processing\"/><diagnostics value=\"" + Msg.code(388) + "/metadata request must use HTTP GET or HTTP HEAD\"/></issue></OperationOutcome>", output);
+		}
+
+		httpOperation = new HttpHead(ourServer.getBaseUrl() + "/metadata");
+		try (CloseableHttpResponse status = ourClient.execute(httpOperation)) {
+			assertEquals(200, status.getStatusLine().getStatusCode());
+			assertNull(status.getEntity());
 		}
 
 		/*