Add support for the client supporting serializing enum values

client/implementation/src/main/java/io/smallrye/graphql/client/impl/RequestImpl.java

@@ -70,6 +70,8 @@ private JsonObject _formatJsonVariables() {
                 varBuilder.add(k, (Long) v);
             } else if (v instanceof Double) {
                 varBuilder.add(k, (Double) v);
+            } else if (v instanceof Enum<?>) {
+                varBuilder.add(k, ((Enum<?>) v).name());
             } else if (v == null) {
                 varBuilder.addNull(k);
             } else {

client/implementation/src/test/java/io/smallrye/graphql/client/RequestImplTest.java

@@ -49,5 +49,18 @@ public void testComplexTypesToJson() {
         map.put("ids", arr);
         request.setVariable("key", map);
         assertEquals("{\"query\":\"example\",\"variables\":{\"key\":{\"ids\":[1,2]}}}", request.toJson());
+
+        request.setVariable("key", new TestRecord(TestEnum.TEST));
+        assertEquals("{\"query\":\"example\",\"variables\":{\"key\":{\"enumValue\":\"TEST\"}}}", request.toJson());
+
+        request.setVariable("key", TestEnum.TEST);
+        assertEquals("{\"query\":\"example\",\"variables\":{\"key\":\"TEST\"}}", request.toJson());
+    }
+
+    public record TestRecord(TestEnum enumValue) {
+    }
+
+    public enum TestEnum {
+        TEST
     }
 }

server/integration-tests/src/test/java/io/smallrye/graphql/tests/client/dynamic/DummyEnum.java

@@ -0,0 +1,8 @@
+package io.smallrye.graphql.tests.client.dynamic;
+
+public enum DummyEnum {
+    ZERO,
+    ONE,
+    TWO,
+    THREE
+}

server/integration-tests/src/test/java/io/smallrye/graphql/tests/client/dynamic/DynamicClientApi.java

@@ -43,6 +43,13 @@ public Dummy queryWithArgument2(@Name(value = "obj") DummyObject obj) {
         return ret;
     }
 
+    @Query
+    public Dummy queryWithArgument3(@Name(value = "obj") DummyEnum obj) {
+        Dummy ret = new Dummy();
+        ret.setInteger(obj.ordinal());
+        return ret;
+    }
+
     @Query
     public Dummy withRenamedField() {
         Dummy ret = new Dummy();

server/integration-tests/src/test/java/io/smallrye/graphql/tests/client/dynamic/DynamicClientInjectionTest.java

@@ -39,7 +39,7 @@ public static WebArchive deployment() {
                         "dummy/mp-graphql/url=http://localhost:9090/client-injection-test/graphql\n" +
                                 "dummy/mp-graphql/header/My-Custom-Header=Header-Value"),
                         "META-INF/microprofile-config.properties")
-                .addClasses(DynamicClientApi.class, DummyObject.class, Dummy.class);
+                .addClasses(DynamicClientApi.class, DummyObject.class, DummyEnum.class, Dummy.class);
     }
 
     @Inject

server/integration-tests/src/test/java/io/smallrye/graphql/tests/client/dynamic/DynamicClientSingleOperationsTestBase.java

@@ -36,7 +36,7 @@ public abstract class DynamicClientSingleOperationsTestBase {
     @Deployment
     public static WebArchive deployment() {
         return ShrinkWrap.create(WebArchive.class, "integration-test.war")
-                .addClasses(DynamicClientApi.class, DummyObject.class, Dummy.class);
+                .addClasses(DynamicClientApi.class, DummyObject.class, DummyEnum.class, Dummy.class);
     }
 
     @ArquillianResource
@@ -96,6 +96,17 @@ public void testStringQueryWithObject() throws ExecutionException, InterruptedEx
         assertEquals("a", data.getJsonObject("queryWithArgument2").getJsonObject("dummyObject").getString("a"));
     }
 
+    @Test
+    public void testStringQueryWithEnum() throws ExecutionException, InterruptedException {
+        Map<String, Object> vars = new HashMap<>();
+        vars.put("x", DummyEnum.TWO);
+        JsonObject data = client
+                .executeSync("query($x: DummyEnum) {queryWithArgument3(obj: $x){integer}}", vars)
+                .getData();
+        System.out.println(data);
+        assertEquals(2, data.getJsonObject("queryWithArgument3").getInt("integer"));
+    }
+
     @Test
     public void testStringQueryWithMultipleOperations() throws ExecutionException, InterruptedException {
         String query = "query a {simple{integer}} " +