OpenAPI: better auto tag when using interfaces / abstract classes

extensions/smallrye-openapi/deployment/src/main/java/io/quarkus/smallrye/openapi/deployment/SmallRyeOpenApiProcessor.java

@@ -4,6 +4,7 @@
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
+import java.lang.reflect.Modifier;
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Path;
@@ -427,7 +428,21 @@ private Map<String, String> getClassNamesMethodReferences(OpenApiFilteredIndexVi
             if (ai.target().kind().equals(AnnotationTarget.Kind.METHOD)) {
                 MethodInfo method = ai.target().asMethod();
                 String ref = JandexUtil.createUniqueMethodReference(method);
-                classNames.put(ref, method.declaringClass().simpleName());
+                if (Modifier.isInterface(method.declaringClass().flags())) {
+                    Collection<ClassInfo> allKnownImplementors = apiFilteredIndexViewBuildItem.getIndex()
+                            .getAllKnownImplementors(method.declaringClass().name());
+                    for (ClassInfo impl : allKnownImplementors) {
+                        classNames.put(ref, impl.simpleName());
+                    }
+                } else if (Modifier.isAbstract(method.declaringClass().flags())) {
+                    Collection<ClassInfo> allKnownSubclasses = apiFilteredIndexViewBuildItem.getIndex()
+                            .getAllKnownSubclasses(method.declaringClass().name());
+                    for (ClassInfo impl : allKnownSubclasses) {
+                        classNames.put(ref, impl.simpleName());
+                    }
+                } else {
+                    classNames.put(ref, method.declaringClass().simpleName());
+                }
             }
         }
         return classNames;

extensions/smallrye-openapi/deployment/src/test/java/io/quarkus/smallrye/openapi/test/jaxrs/AbstractAutoTagResource.java

@@ -0,0 +1,14 @@
+package io.quarkus.smallrye.openapi.test.jaxrs;
+
+import javax.ws.rs.GET;
+import javax.ws.rs.Path;
+import javax.ws.rs.PathParam;
+import javax.ws.rs.Produces;
+import javax.ws.rs.core.MediaType;
+
+@Produces(MediaType.TEXT_PLAIN)
+public interface AbstractAutoTagResource<T> {
+    @GET
+    @Path("/{id}")
+    T getById(@PathParam("id") long id);
+}

extensions/smallrye-openapi/deployment/src/test/java/io/quarkus/smallrye/openapi/test/jaxrs/AutoTagResource.java

@@ -0,0 +1,11 @@
+package io.quarkus.smallrye.openapi.test.jaxrs;
+
+import javax.ws.rs.Path;
+
+@Path("/address")
+public class AutoTagResource implements AbstractAutoTagResource<String> {
+    @Override
+    public String getById(long id) {
+        return "Disney Land, Gate " + id;
+    }
+}

extensions/smallrye-openapi/deployment/src/test/java/io/quarkus/smallrye/openapi/test/jaxrs/AutoTagTestCase.java

@@ -11,7 +11,7 @@ public class AutoTagTestCase {
     @RegisterExtension
     static QuarkusUnitTest runner = new QuarkusUnitTest()
             .withApplicationRoot((jar) -> jar
-                    .addClasses(OpenApiResourceWithNoTag.class));
+                    .addClasses(OpenApiResourceWithNoTag.class, AutoTagResource.class, AbstractAutoTagResource.class));
 
     @Test
     public void testAutoSecurityRequirement() {
@@ -28,4 +28,13 @@ public void testAutoSecurityRequirement() {
 
     }
 
+    @Test
+    public void testTagInOpenApi() {
+        RestAssured.given().header("Accept", "application/json")
+                .when().get("/q/openapi")
+                .then()
+                .statusCode(200)
+                .body(Matchers.containsString("Auto Tag Resource"));
+    }
+
 }