Fragments that assign to arrays only assign the last parsed element

[daumantas-kavolis-sensmetry]

Langium version: 1.0.1 Package name: langium

Fragments that assign to an array only assign the last parsed element when used with + or * cardinalities. This is a serious bug that prevents using fragment composition in more complex grammars for parsing declarations and bodies without resorting to copy-pasting .

Steps To Reproduce

1. Replace

entry Model:
    (persons+=Person | greetings+=Greeting)*;

with

entry Model:
    ModelItem*;

fragment ModelItem:
    persons+=Person | greetings+=Greeting;

Link to code example:

Link to playground

The current behavior

{
  $type: "Model",
  greetings: [
    {
      $type: "Greeting",
      person: Reference("/persons@0"),
    },
  ],
  persons: [
    {
      $type: "Person",
      name: "Jane",
    },
  ],
}

The expected behavior

{
  $type: "Model",
  persons: [
    {
      $type: "Person",
      name: "John",
    },
    {
      $type: "Person",
      name: "Jane",
    },
  ],
  greetings: [
    {
      $type: "Greeting",
      person: Reference("/persons@0"),
    },
    {
      $type: "Greeting",
      person: Reference("/persons@1"),
    },
  ],
}

[msujew]

Hey @daumantas-kavolis-sensmetry, thanks for the report. I've created #898 to fix this issue.