BUG: Eel arrow function, without arguments.

[mhsdesign]

Description

Eel arrow functions dont work with zero arguments like:

() => 'foo'

It is parsed correctly, but the CompilingEelParser doesnt handle this case: This line is failing: https://github.com/neos/flow-development-collection/blob/8a6154d3e11d7b229fa5c8b47d4650d1a7e7cd4f/Neos.Eel/Classes/CompilingEelParser.php#L323

Steps to Reproduce

run this Fusion:

root = ${Array.map([''], () => "foo")[0]}

(it works in the fusionpen because the php error_reporting is turned off)

Expected behavior

output "foo"

Actual behavior

Neos\Flow\Error\Exception: Notice: Undefined index: val in Data/Temporary/Testing/Cache/Code/Flow_Object_Classes/Neos_Eel_CompilingEelParser.php line 323

Affected Versions

Flow: since at least 6.3