Add federation Resolver annotation to index

extensions/smallrye-graphql/deployment/src/main/java/io/quarkus/smallrye/graphql/deployment/SmallRyeGraphQLProcessor.java

@@ -94,6 +94,7 @@
 import io.smallrye.graphql.api.federation.Key;
 import io.smallrye.graphql.api.federation.Provides;
 import io.smallrye.graphql.api.federation.Requires;
+import io.smallrye.graphql.api.federation.Resolver;
 import io.smallrye.graphql.api.federation.Shareable;
 import io.smallrye.graphql.api.federation.Tag;
 import io.smallrye.graphql.api.federation.link.Import;
@@ -321,6 +322,7 @@ void buildFinalIndex(
             indexer.indexClass(ScopeGroup.class);
             indexer.indexClass(ScopeItem.class);
             indexer.indexClass(Namespace.class);
+            indexer.indexClass(Resolver.class);
         } catch (IOException ex) {
             LOG.warn("Failure while creating index", ex);
         }

extensions/smallrye-graphql/deployment/src/test/java/io/quarkus/smallrye/graphql/deployment/federation/resolver/ExtendedApi.java

@@ -0,0 +1,25 @@
+package io.quarkus.smallrye.graphql.deployment.federation.resolver;
+
+import org.eclipse.microprofile.graphql.GraphQLApi;
+
+import io.smallrye.graphql.api.federation.Resolver;
+
+@GraphQLApi
+public class ExtendedApi {
+    @Resolver
+    public ExtendedType extendedTypeById(String id) {
+        ExtendedType extendedType = new ExtendedType();
+        extendedType.setId(id);
+        extendedType.setDescription("extendedTypeById");
+        return extendedType;
+    }
+
+    @Resolver
+    public ExtendedType extendedTypeByIdNameKey(String id, String name, String key) {
+        ExtendedType extendedType = new ExtendedType();
+        extendedType.setId(id);
+        extendedType.setValue(id + name + key);
+        extendedType.setDescription("extendedTypeByIdNameKey");
+        return extendedType;
+    }
+}

extensions/smallrye-graphql/deployment/src/test/java/io/quarkus/smallrye/graphql/deployment/federation/resolver/ExtendedType.java

@@ -0,0 +1,65 @@
+package io.quarkus.smallrye.graphql.deployment.federation.resolver;
+
+import io.smallrye.graphql.api.federation.Extends;
+import io.smallrye.graphql.api.federation.External;
+import io.smallrye.graphql.api.federation.FieldSet;
+import io.smallrye.graphql.api.federation.Key;
+import io.smallrye.graphql.api.federation.Requires;
+
+@Extends
+@Key(fields = @FieldSet("id"))
+public class ExtendedType {
+    @External
+    private String id;
+
+    @External
+    private String name;
+
+    @External
+    private String key;
+
+    @Requires(fields = @FieldSet("name key"))
+    private String value;
+
+    private String description;
+
+    public String getId() {
+        return id;
+    }
+
+    public void setId(String id) {
+        this.id = id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public String getKey() {
+        return key;
+    }
+
+    public void setKey(String key) {
+        this.key = key;
+    }
+
+    public String getValue() {
+        return value;
+    }
+
+    public void setValue(String value) {
+        this.value = value;
+    }
+
+    public String getDescription() {
+        return description;
+    }
+
+    public void setDescription(String description) {
+        this.description = description;
+    }
+}

extensions/smallrye-graphql/deployment/src/test/java/io/quarkus/smallrye/graphql/deployment/federation/resolver/FederationResolverTest.java

@@ -0,0 +1,77 @@
+package io.quarkus.smallrye.graphql.deployment.federation.resolver;
+
+import org.hamcrest.CoreMatchers;
+import org.jboss.shrinkwrap.api.asset.EmptyAsset;
+import org.jboss.shrinkwrap.api.asset.StringAsset;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.RegisterExtension;
+
+import io.quarkus.smallrye.graphql.deployment.AbstractGraphQLTest;
+import io.quarkus.test.QuarkusUnitTest;
+import io.restassured.RestAssured;
+
+public class FederationResolverTest extends AbstractGraphQLTest {
+
+    @RegisterExtension
+    static QuarkusUnitTest test = new QuarkusUnitTest()
+            .withApplicationRoot((jar) -> jar
+                    .addClasses(ExtendedApi.class, ExtendedType.class)
+                    .addAsResource(new StringAsset("quarkus.smallrye-graphql.schema-include-directives=true"),
+                            "application.properties")
+                    .addAsManifestResource(EmptyAsset.INSTANCE, "beans.xml"));
+
+    @Test
+    public void resolverById() {
+        String request = getPayload(TEST_ID_QUERY);
+        RestAssured.given().when()
+                .accept(MEDIATYPE_JSON)
+                .contentType(MEDIATYPE_JSON)
+                .body(request)
+                .post("/graphql")
+                .then()
+                .assertThat()
+                .statusCode(200)
+                .and()
+                .body(CoreMatchers.is(
+                        "{\"data\":{\"_entities\":[{\"id\":\"id\",\"description\":\"extendedTypeById\"}]}}"));
+    }
+
+    @Test
+    public void resolverByIdNameKey() {
+        String request = getPayload(TEST_ID_NAME_KEY_QUERY);
+        RestAssured.given().when()
+                .accept(MEDIATYPE_JSON)
+                .contentType(MEDIATYPE_JSON)
+                .body(request)
+                .post("/graphql")
+                .then()
+                .assertThat()
+                .statusCode(200)
+                .and()
+                .body(CoreMatchers.is(
+                        "{\"data\":{\"_entities\":[{\"id\":\"id\",\"value\":\"idnamekey\",\"description\":\"extendedTypeByIdNameKey\"}]}}"));
+    }
+
+    private static final String TEST_ID_QUERY = "query {\n" +
+            "_entities(\n" +
+            "    representations: { id: \"id\", __typename: \"ExtendedType\" }\n" +
+            ") {\n" +
+            "    ... on ExtendedType {\n" +
+            "        id\n" +
+            "        description\n" +
+            "    }\n" +
+            "  }\n" +
+            "}";
+
+    private static final String TEST_ID_NAME_KEY_QUERY = "query {\n" +
+            "_entities(\n" +
+            "    representations: { id: \"id\", name: \"name\", key: \"key\", __typename: \"ExtendedType\" }\n" +
+            ") {\n" +
+            "    ... on ExtendedType {\n" +
+            "        id\n" +
+            "        value\n" +
+            "        description\n" +
+            "    }\n" +
+            "  }\n" +
+            "}";
+}