If you use filter without required argument then php throw Type Error.

[PATROMO]

Try:

{{"now"|date }} or {{ 4 | plus }}

and you get:

Type error: Too few arguments to function Liquid\StandardFilters::date(), 1 passed and exactly 2 expected 

An LiquidException should be thrown.

[sanmai]

That is in fact correct. The date filter requires a format.

https://shopify.github.io/liquid/filters/date/

[PATROMO]

I know, but LiquidException should be thrown and not a PHP Error.

[sanmai]

Fair.

[PATROMO]

I will try to create a PR for it. :)

[sanmai]

Consider catching TypeError somewhere up the stack, and rethrowing a LiquidException with that TypeError set as a previous exception. That'll be a solution for all other similar cases too.