@Test
	public void processingChain() {
		String processingChainUnderTest = "transform --expression='payload.toUpperCase()' | filter --expression='payload.length() > 4'";

		SingleNodeProcessingChain chain = chain(application, "eezypeasy", processingChainUnderTest);

		chain.sendPayload("hello");
		String result = (String) chain.receivePayload(RECEIVE_TIMEOUT);
		assertEquals("HELLO", result);

		chain.sendPayload("a");
		result = (String) chain.receivePayload(RECEIVE_TIMEOUT);
		assertNull(result);

		chain.destroy();
	}
Test a simple processing chain by sending and receiving payloads.
spring-xd-dirt/src/test/java/org/springframework/xd/dirt/stream/ExampleProcessingChainTests.java