[GROOVY-6835] flow typing activated by if statement doing an "instanceof" check doesn't work as expected with interface types

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.3.2, 2.4.0-rc-1
• Fix Version/s: 2.4.6
• Component/s: Static Type Checker

Language

groovy

• Assignee: Paul King
• Reporter: Lari Hotari
• Created: 29/May/14 02:49
• Updated: 11/Nov/24 20:15
• Resolved: 05/Jan/16 03:14

Description

The following code example fails with this STC error in compilation:

1 compilation error:

[Static type checking] - Cannot call java.util.Set <CharSequence>#add(java.lang.CharSequence) with arguments [<UnionTypejava.lang.Object+java.lang.CharSequence>] 
 at line: 10, column: 12

@groovy.transform.CompileStatic
class ShowUnionTypeBug {
    Map<String, Object> instanceMap = (Map<String,Object>)['a': 'Hello World']
    def findInstance(String key) {
        Set<CharSequence> allInstances = [] as Set
        def instance = instanceMap.get(key)
        if(instance instanceof CharSequence) {
           allInstances.add(instance)
        }
        allInstances
    }
}
new ShowUnionTypeBug().findInstance('a')

Issue Links

• is related to: GROOVY-9074 CompileStatic does not throw expected exception