HeaderEnricher: Add test using stream test utils

Author: garyrussell

spring-kafka/src/test/java/org/springframework/kafka/streams/HeaderEnricherTests.java

@@ -0,0 +1,77 @@
+/*
+ * Copyright 2019 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.kafka.streams;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Properties;
+
+import org.apache.kafka.clients.producer.ProducerRecord;
+import org.apache.kafka.common.serialization.StringSerializer;
+import org.apache.kafka.streams.StreamsBuilder;
+import org.apache.kafka.streams.StreamsConfig;
+import org.apache.kafka.streams.TopologyTestDriver;
+import org.apache.kafka.streams.kstream.KStream;
+import org.apache.kafka.streams.test.ConsumerRecordFactory;
+import org.junit.jupiter.api.Test;
+
+import org.springframework.expression.Expression;
+import org.springframework.expression.common.LiteralExpression;
+import org.springframework.expression.spel.standard.SpelExpressionParser;
+
+/**
+ * @author Gary Russell
+ * @since 2.3
+ *
+ */
+public class HeaderEnricherTests {
+
+	private static final String INPUT = "input";
+
+	private static final String OUTPUT = "output";
+
+	@Test
+	void testWithDriver() {
+		StreamsBuilder builder = new StreamsBuilder();
+		Map<String, Expression> headers = new HashMap<>();
+		headers.put("foo", new LiteralExpression("bar"));
+		SpelExpressionParser parser = new SpelExpressionParser();
+		headers.put("spel", parser.parseExpression("context.timestamp() + new String(key) + new String(value)"));
+		HeaderEnricher<String, String> enricher = new HeaderEnricher<>(headers);
+		KStream<String, String> stream = builder.stream(INPUT);
+		stream
+				.transform(() -> enricher)
+				.to(OUTPUT);
+
+		Properties config = new Properties();
+		config.put(StreamsConfig.APPLICATION_ID_CONFIG, "test");
+		config.put(StreamsConfig.BOOTSTRAP_SERVERS_CONFIG, "localhost:9999");
+		TopologyTestDriver driver = new TopologyTestDriver(builder.build(), config);
+
+		ConsumerRecordFactory<String, String> recordFactory = new ConsumerRecordFactory<>(new StringSerializer(),
+				new StringSerializer());
+		driver.pipeInput(recordFactory.create(INPUT, "key", "value"));
+		ProducerRecord<byte[], byte[]> result = driver.readOutput(OUTPUT);
+		assertThat(result.headers().lastHeader("foo")).isNotNull();
+		assertThat(result.headers().lastHeader("foo").value()).isEqualTo("bar".getBytes());
+		assertThat(result.headers().lastHeader("spel")).isNotNull();
+		driver.close();
+	}
+
+}