elsif inside else does not raise errors when parsing

{% assign randomNumber = first_name | size | modulo: 3 | plus: 1 %}
{% if randomNumber == 1 %}
Test
{% else %}
{% elsif randomNumber == 2 %}
Test 2
{% else %}
Test 3
{% endif %} 

In the following example, the user added an elsif inside an else block, whcih should be considered invalid.
However, when this block runs it doesn't return anything.

Liquid::Template.parse(stage.body, error_mode: :strict) --> works without any error when it should.
When rendering the result above, fails to run this block.

Start by reproducing the supplied template with Liquid::Template.parse(..., error_mode: :strict) and confirm that the invalid elsif inside else is accepted. Trace the parser handling for else and elsif, then add a regression test in the relevant parser or error-mode test suite. Done means strict parsing raises an error for this structure and valid conditional branches still parse.