Add unit tests for LlamaEmbeddingsRequestEntity to validate XContent serialization

Author: Jan-Kazlouski-elastic

x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/llama/request/embeddings/LlamaEmbeddingsRequestEntityTests.java

@@ -0,0 +1,38 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0; you may not use this file except in compliance with the Elastic License
+ * 2.0.
+ */
+
+package org.elasticsearch.xpack.inference.services.llama.request.embeddings;
+
+import org.elasticsearch.common.Strings;
+import org.elasticsearch.common.xcontent.XContentHelper;
+import org.elasticsearch.test.ESTestCase;
+import org.elasticsearch.xcontent.XContentBuilder;
+import org.elasticsearch.xcontent.XContentFactory;
+import org.elasticsearch.xcontent.XContentType;
+
+import java.io.IOException;
+import java.util.List;
+
+import static org.hamcrest.CoreMatchers.is;
+
+public class LlamaEmbeddingsRequestEntityTests extends ESTestCase {
+
+    public void testXContent_Success() throws IOException {
+        var entity = new LlamaEmbeddingsRequestEntity("llama-embed", List.of("ABDC"));
+
+        XContentBuilder builder = XContentFactory.contentBuilder(XContentType.JSON);
+        entity.toXContent(builder, null);
+        String xContentResult = Strings.toString(builder);
+
+        assertThat(xContentResult, is(XContentHelper.stripWhitespace("""
+            {
+                "model_id": "llama-embed",
+                "contents": ["ABDC"]
+            }
+            """)));
+    }
+}