[GROOVY-10223] Add support for Optional to DefaultTypeTransformation.asCollection()

• Type: Improvement
• Status: Closed
• Priority: Trivial
• Resolution: Fixed
• Fix Version/s: 5.0.0-alpha-1
• Component/s: groovy-jdk
• Labels: features

Language

groovy

• Assignee: Eric Milles
• Reporter: Stephen Smith
• Created: 10/Sep/21 20:57
• Updated: 23/Aug/23 09:11
• Resolved: 27/Jun/22 17:42

Description

The JDK recently added support for Optional::stream() which returns a stream containing either the unwrapped value or an empty stream if the Optional is empty.

In the groovy-jdk, using iteration however will call

DefaultTypeTransformation.asCollection()

which does not specifically check for type Optional, instead it will just wrap the Optional itself in a List rather than the unwrapped value as the default behavior.

Adding an if else clause will allow using the Optional as either a single or empty list.

if (value instanceOf Optional) {
   return ((Optional)value).map(List::of).orElse(List.of())
}

 Alternatively, add an asList() to the Optional class.

 (edit: 2021-09-13, missing bracket in code example)

 

Issue Links

• relates to: GROOVY-10616 Add peek extension method for Optional, OptionalInt, OptionalLong and OptionalDouble
• links to: GitHub Pull Request #1732