OPEN - BATCH-806: Resurrect ResourceLineReader

RLR is back on stage - TODO find a sensible way to encapsulate duplications with FFIR

spring-batch-infrastructure/src/test/java/org/springframework/batch/item/file/ResourceLineReaderTests.java

@@ -0,0 +1,168 @@
+package org.springframework.batch.item.file;
+
+import static org.junit.Assert.*;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.springframework.batch.item.ExecutionContext;
+import org.springframework.batch.item.file.separator.RecordSeparatorPolicy;
+import org.springframework.core.io.ByteArrayResource;
+import org.springframework.core.io.DescriptiveResource;
+import org.springframework.core.io.Resource;
+
+/**
+ * Tests for {@link ResourceLineReader}.
+ */
+public class ResourceLineReaderTests {
+
+	private ResourceLineReader tested;
+
+	private static final Resource resource = new ByteArrayResource("line1\nline2\nline3\nline4\nline5".getBytes());
+
+	private ExecutionContext executionContext = new ExecutionContext();
+
+	private static ResourceLineReader getItemReader() {
+		ResourceLineReader result = new ResourceLineReader();
+		result.setResource(resource);
+		return result;
+	}
+
+	@Before
+	public void setUp() throws Exception {
+		tested = getItemReader();
+		tested.open(executionContext);
+	}
+
+	/**
+	 * Regular scenario - read the input and eventually return null.
+	 */
+	@Test
+	public void testRead() throws Exception {
+
+		assertEquals("line1", tested.read());
+		assertEquals("line2", tested.read());
+		assertEquals("line3", tested.read());
+		assertEquals("line4", tested.read());
+		assertEquals("line5", tested.read());
+
+		assertNull(tested.read());
+	}
+
+	/**
+	 * No input should be handled gracefully - null is returned on first
+	 * read.
+	 */
+	@Test
+	public void testNoInput() throws Exception {
+		tested = getItemReader();
+		tested.setResource(new DescriptiveResource("doesn't exist") {
+
+			@Override
+			public boolean exists() {
+				return false;
+			}
+			
+		});
+		tested.open(executionContext);
+		assertNull(tested.read());
+	}
+
+	/**
+	 * Restart scenario - read items, update execution context, create new
+	 * reader and restore from restart data - the new input source should
+	 * continue where the old one finished.
+	 */
+	@Test
+	public void testRestart() throws Exception {
+
+		tested.update(executionContext);
+
+		assertEquals("line1", tested.read());
+		assertEquals("line2", tested.read());
+
+		tested.update(executionContext);
+
+		// create new input source
+		tested = getItemReader();
+
+		tested.open(executionContext);
+
+		assertEquals("line3", tested.read());
+	}
+
+	/**
+	 * Restart scenario - read items, rollback to last marked position, update
+	 * execution context, create new reader and restore from restart data - the
+	 * new input source should continue where the old one finished.
+	 */
+	@Test
+	public void testResetAndRestart() throws Exception {
+
+		tested.update(executionContext);
+
+		assertEquals("line1", tested.read());
+
+		assertEquals("line2", tested.read());
+
+		tested.update(executionContext);
+
+		assertEquals("line3", tested.read());
+
+		// create new input source
+		tested = getItemReader();
+
+		tested.open(executionContext);
+
+		assertEquals("line3", tested.read());
+	}
+
+	@Test
+	public void testReopen() throws Exception {
+		tested.update(executionContext);
+
+		assertEquals("line1", tested.read());
+		assertEquals("line2", tested.read());
+
+		tested.update(executionContext);
+
+		
+		tested.close(executionContext);
+		tested.open(executionContext);
+
+		assertEquals("line3", tested.read());
+	}
+	
+	@Test
+	public void testRestartWithCustomRecordSeparatorPolicy() throws Exception {
+		
+		tested.setRecordSeparatorPolicy(new RecordSeparatorPolicy() {
+			// 1 record = 2 lines
+			boolean pair = true;
+
+			public boolean isEndOfRecord(String line) {
+				pair = !pair;
+				return pair;
+			}
+
+			public String postProcess(String record) {
+				return record;
+			}
+
+			public String preProcess(String record) {
+				return record;
+			}
+		});
+
+		tested.open(executionContext);
+
+		assertEquals("line1line2", tested.read());
+		
+		tested.update(executionContext);
+		tested.close(executionContext);
+		tested.open(executionContext);
+		
+		assertEquals("line3line4", tested.read());
+		
+	}
+
+}