[GROOVY-11276] Generics error in method resolution

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 3.0.20, 4.0.17
• Fix Version/s: 4.0.18, 3.0.21
• Component/s: Static Type Checker
• Assignee: Eric Milles
• Reporter: Christopher Smith
• Created: 11/Jan/24 23:11
• Updated: 05/Mar/24 01:53
• Resolved: 12/Jan/24 20:43

Description

There's a chance this is a duplicate of a ticket recently fixed, but it's odd enough (and the message is unclear enough) that I'm reposting it.

Map<String, List<String>> idsForAccounts(Collection<String> persons) {
  Map<Object, Object> fromGraph = retrieve()

  // workaround for buggy database implementation follows
  new HashMap<String, List<String>>().tap { result ->
    putAll(fromGraph as Map<String, List<String>>)
    persons.forEach {
      if (!result.containsKey(it)) {
        result.put(it, emptyList())
      }
    }
  }
}

[Static type checking] - Cannot find matching method java.util.HashMap#put(java.lang.String, java.util.List<#T>). Please check if the declared type is correct and if the method exists.
  @ line 73, column 21.
        result.put(it, emptyList())
        ^

Update: Using a type witness as Collections.<String> emptyList() works.

Issue Links

• is related to: GROOVY-11057 STC Generic type matching failure