$$ components
{% component button(name, age) %}Hello {{name}}, you are {{age}}{% endcomponent %}
{% component open_button(name, age, ...rest) %}Hello {{name}}, age {{age}}, extras: {{rest | length}}{% endcomponent %}
$$ tpl
{% set props = {"name": "Alice", "age": 25} %}
Basic spread: {{<button {...props}/>}}
Spread with override (explicit wins): {{<button {...props} age={30}/>}}
Override then spread (spread wins): {{<button age={30} {...props}/>}}
{% set base = {"name": "Charlie"} %}
{% set more = {"age": 35} %}
Multiple spreads: {{<button {...base} {...more}/>}}
Mix explicit and spread: {{<button name="Explicit" {...more}/>}}
--- Rest param tests ---
{% set extra = {"name": "Bob", "age": 20, "class": "btn", "id": "my-btn"} %}
Open component accepts extras: {{<open_button {...extra}/>}}
Forward extras to child: {{<open_button name="Test" age={10} foo="bar" baz={123}/>}}
{% set empty = {} %}
Open component with empty spread: {{<open_button name="a" age={2} {...empty}/>}}