[GROOVY-7247] spreadMap type inference is incorrect and STC reports on valid code

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 4.0.5, 2.5.19, 3.0.13
• Component/s: Static Type Checker
• Assignee: Eric Milles
• Reporter: UEHARA Junji
• Created: 12/Jan/15 03:32
• Updated: 10/Feb/23 21:40
• Resolved: 18/Aug/22 19:18

Description

STC reports false error on spreadMap operation:

@groovy.transform.TypeChecked
def f() {
    Map<String, Integer> map1 = [ *:[A:1], *:[B:2]] // [Static type checking] - Incompatible generic argument types. Cannot assign java.util.LinkedHashMap <java.util.Map, java.util.LinkedHashMap> to: java.util.Map <String, Integer>
    assert map1  == [A:1, B:2]
    println map1

    Map<String, Integer> submap1 = [A: 1]
    Map<String, Integer> submap2 = [B: 2]
    Map<String, Integer> map2 = [*:submap1, *:submap2] // [Static type checking] - Incompatible generic argument types. Cannot assign java.util.LinkedHashMap <java.util.Map, java.util.LinkedHashMap> to: java.util.Map <String, Integer>
    assert map2  == [A:1, B:2]
    println map2
}

f()