[GROOVY-9603] Assignment of Map literal to Map element fails to compile (static)

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.0.3, 3.0.4, 2.5.12
• Fix Version/s: 4.0.0-alpha-1, 3.0.5, 2.5.13
• Component/s: Static compilation, Static Type Checker
• Assignee: Eric Milles
• Reporter: Jochen Eddelbuettel
• Created: 20/Jun/20 11:40
• Updated: 23/Jul/20 14:16
• Resolved: 23/Jun/20 04:27

Description

Declare a Map<String,Object>. When trying to put a map literal into that map, assignments in property style (map.key = ...) and subscript style (map[key] = ...) fail with

[Static type checking] - No such property: ... for class: java.lang.Object

First assigning to a local variable gives no such problems. If the Map were to contain objects of a specific type, coercion from map to that particular type would make sense. This coercion from Map to Object makes to sense. A Map is an Object and should simply become the new value for that particular key, which is just what is happening with regular compilation.

Same for Map<String,?> and Map<String,? extends Object

@groovy.transform.CompileStatic
def updateMap(Map<String,Object> map) {
    def innerMap = [ foo: "bar", bar: "foo" ]
    // No problem on this assignment
    map.someProp = innerMap
    assert map.someProp["foo"] == "bar"
    // The next three lines should all be equivalent
    // but the 2nd and 3rd don't CompileStatic
    map.put("someProp", [ abc: "efg" ])
    map["someProp"] = [ abc: "hij" ]
    map.someProp = [ abc: "klm" ]
    assert map.someProp["abc"] == "klm"
}