SPR-6984: auto grow collections on write through indexer

org.springframework.expression/src/test/java/org/springframework/expression/spel/EvaluationTests.java

@@ -31,6 +31,7 @@ import org.springframework.expression.spel.standard.SpelExpression;
 import org.springframework.expression.spel.standard.SpelExpressionParser;
 import org.springframework.expression.spel.support.StandardEvaluationContext;
 import org.springframework.expression.spel.support.StandardTypeLocator;
+import org.springframework.expression.spel.testresources.TestPerson;
 
 /**
  * Tests the evaluation of real expressions in a real context.
@@ -520,6 +521,33 @@ public class EvaluationTests extends ExpressionTestCase {
 	public void testResolvingString() throws Exception {
 		Class stringClass = parser.parseExpression("T(String)").getValue(Class.class);
 		Assert.assertEquals(String.class,stringClass);
-	}
+	} 
+	 
+	/**
+	 * SPR-6984: attempting to index a collection on write using an index that doesn't currently exist in the collection (address.crossStreets[0] below)
+	 */
+	@Test
+	public void initializingCollectionElementsOnWrite() throws Exception {
+		TestPerson person = new TestPerson();
+		EvaluationContext context = new StandardEvaluationContext(person);
+		SpelParserConfiguration config = new SpelParserConfiguration(true, true);
+		ExpressionParser parser = new SpelExpressionParser(config);
+		Expression expression = parser.parseExpression("name");
+		expression.setValue(context, "Oleg");
+		Assert.assertEquals("Oleg",person.getName());
 
+		expression = parser.parseExpression("address.street");
+		expression.setValue(context, "123 High St");
+		Assert.assertEquals("123 High St",person.getAddress().getStreet());
+		
+		expression = parser.parseExpression("address.crossStreets[0]");
+		expression.setValue(context, "Blah");
+		Assert.assertEquals("Blah",person.getAddress().getCrossStreets().get(0));
+		
+		expression = parser.parseExpression("address.crossStreets[3]");
+		expression.setValue(context, "Wibble");
+		Assert.assertEquals("Blah",person.getAddress().getCrossStreets().get(0));
+		Assert.assertEquals("Wibble",person.getAddress().getCrossStreets().get(3));
+	}
+	
 }

org.springframework.expression/src/test/java/org/springframework/expression/spel/testresources/TestAddress.java

@@ -0,0 +1,21 @@
+package org.springframework.expression.spel.testresources;
+
+import java.util.List;
+
+public class TestAddress{
+		private String street;
+		private List<String> crossStreets;
+		
+		public String getStreet() {
+			return street;
+		}
+		public void setStreet(String street) {
+			this.street = street;
+		}
+		public List<String> getCrossStreets() {
+			return crossStreets;
+		}
+		public void setCrossStreets(List<String> crossStreets) {
+			this.crossStreets = crossStreets;
+		}
+	}

org.springframework.expression/src/test/java/org/springframework/expression/spel/testresources/TestPerson.java

@@ -0,0 +1,19 @@
+package org.springframework.expression.spel.testresources;
+
+public class TestPerson {
+		private String name;
+		private TestAddress address;
+		
+		public String getName() {
+			return name;
+		}
+		public void setName(String name) {
+			this.name = name;
+		}
+		public TestAddress getAddress() {
+			return address;
+		}
+		public void setAddress(TestAddress address) {
+			this.address = address;
+		}
+	}