[GROOVY-8652] Putting key on generic Map fails when using CompileStatic

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 3.0.0-alpha-2, 2.4.15, 2.5.0
• Fix Version/s: 4.0.0-beta-1, 3.0.9, 2.5.16
• Component/s: Static compilation
• Labels: compilestatic
• Environment: Elementary OS Freya 0.3.2 ; java version "1.8.0_121" ; Java(TM) SE Runtime Environment (build 1.8.0_121-b13) ; Java HotSpot(TM) 64-Bit Server VM (build 25.121-b13, mixed mode)
• Assignee: Eric Milles
• Reporter: Cleydson José de Figueiredo Júnior
• Created: 19/Jun/18 22:56
• Updated: 03/Feb/22 22:34
• Resolved: 25/Oct/21 14:03

Description

I'm trying to use Groovy's short hand way to put a new key value to an encapsulated Map. But the compilation fails with:

 

[Static type checking] - Cannot assign value of type java.lang.String to variable of type ?   

 

Scenario to reproduce:

import groovy.transform.CompileStatic

@CompileStatic
class MapHolder {
   private Map<?, ?> map = [:]

   Map<?, ?> getMap() {
      return map
   }
}

@CompileStatic
static setMapValue() {
   MapHolder mapHolder = new MapHolder()
   mapHolder.map.key = 'value'
}

setMapValue()

Using the put method works just fine:

import groovy.transform.CompileStatic

@CompileStatic
class MapHolder {
   private Map<?, ?> map = [:]

   Map<?, ?> getMap() {
      return map
   }
}

@CompileStatic
static setMapValue() {
   MapHolder mapHolder = new MapHolder()
   mapHolder.put('key', 'value')
}

setMapValue()