Polishing

Author: sbrannen

framework-docs/modules/ROOT/pages/core/expressions/language-ref/collection-projection.adoc

@@ -13,7 +13,7 @@ Java::
 +
 [source,java,indent=0,subs="verbatim,quotes",role="primary"]
 ----
-	// evaluates to ["SmilJan", "Idvor"]
+	// evaluates to ["Smiljan", "Idvor"]
 	List placesOfBirth = parser.parseExpression("members.![placeOfBirth.city]")
 			.getValue(societyContext, List.class);
 ----
@@ -22,7 +22,7 @@ Kotlin::
 +
 [source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
 ----
-	// evaluates to ["SmilJan", "Idvor"]
+	// evaluates to ["Smiljan", "Idvor"]
 	val placesOfBirth = parser.parseExpression("members.![placeOfBirth.city]")
 	 		.getValue(societyContext) as List<*>
 ----

framework-docs/modules/ROOT/pages/core/expressions/language-ref/operator-safe-navigation.adoc

@@ -1,12 +1,14 @@
 [[expressions-operator-safe-navigation]]
 = Safe Navigation Operator
 
-The safe navigation operator is used to avoid a `NullPointerException` and comes from
-the https://www.groovy-lang.org/operators.html#_safe_navigation_operator[Groovy]
-language. Typically, when you have a reference to an object, you might need to verify that
-it is not null before accessing methods or properties of the object. To avoid this, the
-safe navigation operator returns null instead of throwing an exception. The following
-example shows how to use the safe navigation operator:
+The safe navigation operator (`?`) is used to avoid a `NullPointerException` and comes
+from the https://www.groovy-lang.org/operators.html#_safe_navigation_operator[Groovy]
+language. Typically, when you have a reference to an object, you might need to verify
+that it is not `null` before accessing methods or properties of the object. To avoid
+this, the safe navigation operator returns `null` instead of throwing an exception.
+
+The following example shows how to use the safe navigation operator for property access
+(`?.`).
 
 [tabs]
 ======
@@ -20,13 +22,18 @@ Java::
 	Inventor tesla = new Inventor("Nikola Tesla", "Serbian");
 	tesla.setPlaceOfBirth(new PlaceOfBirth("Smiljan"));
 
-	String city = parser.parseExpression("placeOfBirth?.city").getValue(context, tesla, String.class);
-	System.out.println(city);  // Smiljan
+	// evaluates to "Smiljan"
+	String city = parser.parseExpression("placeOfBirth?.city") // <1>
+			.getValue(context, tesla, String.class);
 
 	tesla.setPlaceOfBirth(null);
-	city = parser.parseExpression("placeOfBirth?.city").getValue(context, tesla, String.class);
-	System.out.println(city);  // null - does not throw NullPointerException!!!
+
+	// evaluates to null - does not throw NullPointerException
+	city = parser.parseExpression("placeOfBirth?.city") // <2>
+			.getValue(context, tesla, String.class);	
 ----
+<1> Use safe navigation operator on non-null `placeOfBirth` property
+<2> Use safe navigation operator on null `placeOfBirth` property
 
 Kotlin::
 +
@@ -38,14 +45,17 @@ Kotlin::
 	val tesla = Inventor("Nikola Tesla", "Serbian")
 	tesla.setPlaceOfBirth(PlaceOfBirth("Smiljan"))
 
-	var city = parser.parseExpression("placeOfBirth?.city").getValue(context, tesla, String::class.java)
-	println(city)  // Smiljan
+	// evaluates to "Smiljan"
+	var city = parser.parseExpression("placeOfBirth?.city") // <1>
+			.getValue(context, tesla, String::class.java)
 
 	tesla.setPlaceOfBirth(null)
-	city = parser.parseExpression("placeOfBirth?.city").getValue(context, tesla, String::class.java)
-	println(city)  // null - does not throw NullPointerException!!!
+
+	// evaluates to null - does not throw NullPointerException
+	city = parser.parseExpression("placeOfBirth?.city") // <2>
+			.getValue(context, tesla, String::class.java)
 ----
+<1> Use safe navigation operator on non-null `placeOfBirth` property
+<2> Use safe navigation operator on null `placeOfBirth` property
 ======
 
-
-

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

@@ -234,7 +234,7 @@ void indexerError() {
 
 		@Test
 		void stringType() {
-			evaluateAndAskForReturnType("getPlaceOfBirth().getCity()", "SmilJan", String.class);
+			evaluateAndAskForReturnType("getPlaceOfBirth().getCity()", "Smiljan", String.class);
 		}
 
 		@Test
@@ -594,7 +594,7 @@ class NestedPropertiesTests {
 			// nested properties
 			@Test
 			void propertiesNested01() {
-				evaluate("placeOfBirth.city", "SmilJan", String.class, true);
+				evaluate("placeOfBirth.city", "Smiljan", String.class, true);
 			}
 
 			@Test

spring-expression/src/test/java/org/springframework/expression/spel/MethodInvocationTests.java

@@ -49,7 +49,7 @@ class MethodInvocationTests extends AbstractExpressionTests {
 
 	@Test
 	void testSimpleAccess01() {
-		evaluate("getPlaceOfBirth().getCity()", "SmilJan", String.class);
+		evaluate("getPlaceOfBirth().getCity()", "Smiljan", String.class);
 	}
 
 	@Test

spring-expression/src/test/java/org/springframework/expression/spel/OperatorTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2023 the original author or authors.
+ * Copyright 2002-2024 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.
@@ -16,6 +16,7 @@
 
 package org.springframework.expression.spel;
 
+import java.lang.reflect.Method;
 import java.math.BigDecimal;
 import java.math.BigInteger;
 
@@ -24,6 +25,8 @@
 import org.springframework.expression.Expression;
 import org.springframework.expression.spel.ast.Operator;
 import org.springframework.expression.spel.standard.SpelExpression;
+import org.springframework.expression.spel.standard.SpelExpressionParser;
+import org.springframework.expression.spel.support.StandardEvaluationContext;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.springframework.expression.spel.SpelMessage.MAX_CONCATENATED_STRING_LENGTH_EXCEEDED;
@@ -670,6 +673,18 @@ void bigIntegers() {
 		evaluate("new java.math.BigInteger('5') ^ 3", new BigInteger("125"), BigInteger.class);
 	}
 
+	@Test
+	void bigIntFunction() throws Exception {
+		SpelExpressionParser parser = new SpelExpressionParser();
+		StandardEvaluationContext context = new StandardEvaluationContext();
+		Method method = BigInteger.class.getMethod("valueOf", long.class);
+		context.registerFunction("bigInt", method);
+
+		Expression expression = parser.parseExpression("3 + #bigInt(5)");
+		BigInteger result = expression.getValue(context, BigInteger.class);
+		assertThat(result).isEqualTo(BigInteger.valueOf(8));
+	}
+
 
 	private Operator getOperatorNode(SpelExpression expr) {
 		SpelNode node = expr.getAST();

spring-expression/src/test/java/org/springframework/expression/spel/PropertyAccessTests.java

@@ -58,7 +58,7 @@ void simpleAccess01() {
 
 	@Test
 	void simpleAccess02() {
-		evaluate("placeOfBirth.city", "SmilJan", String.class);
+		evaluate("placeOfBirth.city", "Smiljan", String.class);
 	}
 
 	@Test

spring-expression/src/test/java/org/springframework/expression/spel/SpelDocumentationTests.java

@@ -65,7 +65,7 @@ class SpelDocumentationTests extends AbstractExpressionTests {
 		GregorianCalendar c = new GregorianCalendar();
 		c.set(1856, 7, 9);
 		tesla = new Inventor("Nikola Tesla", c.getTime(), "Serbian");
-		tesla.setPlaceOfBirth(new PlaceOfBirth("SmilJan"));
+		tesla.setPlaceOfBirth(new PlaceOfBirth("Smiljan"));
 		tesla.setInventions("Telephone repeater", "Rotating magnetic field principle",
 				"Polyphase alternating-current system", "Induction motor", "Alternating-current power transmission",
 				"Tesla coil transformer", "Wireless communication", "Radio", "Fluorescent lights");
@@ -167,7 +167,7 @@ void propertyAccess() {
 			assertThat(year).isEqualTo(1856);
 
 			String city = (String) parser.parseExpression("placeOfBirth.City").getValue(context);
-			assertThat(city).isEqualTo("SmilJan");
+			assertThat(city).isEqualTo("Smiljan");
 		}
 
 		@Test
@@ -616,11 +616,10 @@ void ternary() {
 			StandardEvaluationContext societyContext = new StandardEvaluationContext();
 			societyContext.setRootObject(new IEEE());
 
-
 			parser.parseExpression("Name").setValue(societyContext, "IEEE");
 			societyContext.setVariable("queryName", "Nikola Tesla");
 
-			String expression = "isMember(#queryName)? #queryName + ' is a member of the ' "
+			String expression = "isMember(#queryName) ? #queryName + ' is a member of the ' "
 					+ "+ Name + ' Society' : #queryName + ' is not a member of the ' + Name + ' Society'";
 
 			String queryResultString = parser.parseExpression(expression).getValue(societyContext, String.class);
@@ -629,6 +628,28 @@ void ternary() {
 		}
 	}
 
+	@Nested
+	class SaveNavigationOperator {
+
+		@Test
+		void nullSafePropertyAccess() {
+			Inventor tesla = new Inventor("Nikola Tesla", "Serbian");
+			tesla.setPlaceOfBirth(new PlaceOfBirth("Smiljan"));
+
+			// evaluates to "Smiljan"
+			String city = parser.parseExpression("placeOfBirth?.city") // <1>
+					.getValue(context, tesla, String.class);
+			assertThat(city).isEqualTo("Smiljan");
+
+			tesla.setPlaceOfBirth(null);
+
+			// evaluates to null - does not throw a NullPointerException
+			city = parser.parseExpression("placeOfBirth?.city") // <2>
+					.getValue(context, tesla, String.class);
+			assertThat(city).isNull();
+		}
+	}
+
 	@Nested
 	class CollectionSelection {
 
@@ -650,10 +671,10 @@ class CollectionProjection {
 		@SuppressWarnings("unchecked")
 		void projection() {
 			StandardEvaluationContext societyContext = new StandardEvaluationContext(new IEEE());
-			// evaluates to ["SmilJan", "Idvor"]
+			// evaluates to ["Smiljan", "Idvor"]
 			List placesOfBirth = parser.parseExpression("members.![placeOfBirth.city]")
 					.getValue(societyContext, List.class);
-			assertThat(placesOfBirth).containsExactly("SmilJan", "Idvor");
+			assertThat(placesOfBirth).containsExactly("Smiljan", "Idvor");
 		}
 	}
 

spring-expression/src/test/java/org/springframework/expression/spel/TestScenarioCreator.java

@@ -119,7 +119,7 @@ private static void setupRootContextObject(StandardEvaluationContext context) {
 		GregorianCalendar c = new GregorianCalendar();
 		c.set(1856, 7, 9);
 		Inventor tesla = new Inventor("Nikola Tesla", c.getTime(), "Serbian");
-		tesla.setPlaceOfBirth(new PlaceOfBirth("SmilJan"));
+		tesla.setPlaceOfBirth(new PlaceOfBirth("Smiljan"));
 		tesla.setInventions("Telephone repeater", "Rotating magnetic field principle",
 				"Polyphase alternating-current system", "Induction motor", "Alternating-current power transmission",
 				"Tesla coil transformer", "Wireless communication", "Radio", "Fluorescent lights");