Support compilation of SpEL expressions using `Optional` with null-safe and Elvis operators

[sbrannen]

Overview

In Spring Framework 7.0, we introduced support for support for using Optional with the null-safe and Elvis operators in SpEL expressions; however, such expressions are not yet compilable.

Related Issues

• Support Optional with null-safe and Elvis operators in SpEL expressions #20433
• Document that SpEL expressions using Optional with null-safe and Elvis operators are not compilable #36331

[boroowa]

I want to make it clear - compilable means "is there problem with compilation that throws an exception" or "compilation always returns wrong values (nulls)".

I checked in test cases:

		public record Person(String name, java.util.Optional<String> secondName) {
		}

		@Test
		void exmapleTest() {
			SpelParserConfiguration configuration = new SpelParserConfiguration(
					SpelCompilerMode.IMMEDIATE,
					EvaluationTests.class.getClassLoader()
			);

			Person nataly = new Person("Nataly", Optional.empty());

			//WITH COMPILATION: null
//			var parser = new SpelExpressionParser(configuration);

			//DEFAULTRUNTIME: It works perfectly
			var parser = new SpelExpressionParser();
			var standardEvaluationContext = new StandardEvaluationContext();
			standardEvaluationContext.setVariable("person", nataly);

			Expression expression = parser.parseExpression("#person.secondName ?: 'OtherName'");
			String value = null;
			for(int i = 0; i <= 150; i++) {
				if(i == 149) {
					value = expression.getValue(standardEvaluationContext, String.class);
				} else {
					expression.getValue(standardEvaluationContext, String.class);
				}
			}

			System.out.println(value);
		}

And I seee there is no compilation problem itself, only we wanto to adjust to work like in default mode, am I right? If not, please provide me and example to check.

Have a nice day,

PM