--TEST--
Mapping keys can be any expression that evaluates to a scalar or Stringable
--TEMPLATE--
{# context variable holding a Stringable object #}
{{ {(obj): 'a'}|keys|join(',') }}

{# attribute access on an object yielding a Stringable #}
{{ {(holder.stringable): 'a'}|keys|join(',') }}

{# attribute access yielding a string #}
{{ {(holder.name): 'a'}|keys|join(',') }}

{# filter result yielding a Stringable #}
{{ {(obj|raw): 'a'}|keys|join(',') }}

{# filter result yielding a string #}
{{ {('hello'|upper): 'a'}|keys|join(',') }}

{# filter result yielding an integer (keys stay int) #}
{{ {(holder.name|length): 'a'}|keys|first == 4 ? 'ok' : 'ko' }}

{# method call yielding a Stringable #}
{{ {(holder.getStringable()): 'a'}|keys|join(',') }}

{# mixed static and dynamic keys #}
{{ {'static': 's', (obj): 'd', (holder.name): 'n'}|keys|join(',') }}

{# nested mapping with a dynamic Stringable key #}
{{ {'outer': {(obj): 'inner'}} | json_encode | raw }}
--DATA--
class TwigTestStringy implements \Stringable {
    public function __construct(private string $v) {}
    public function __toString(): string { return $this->v; }
}
class TwigTestHolder {
    public string $name = 'attr';
    public TwigTestStringy $stringable;
    public function __construct() { $this->stringable = new TwigTestStringy('attr_obj'); }
    public function getStringable(): TwigTestStringy { return new TwigTestStringy('method_obj'); }
}
return ['obj' => new TwigTestStringy('ctx_obj'), 'holder' => new TwigTestHolder()]
--EXPECT--
ctx_obj

attr_obj

attr

ctx_obj

HELLO

ok

method_obj

static,ctx_obj,attr

{"outer":{"ctx_obj":"inner"}}