Comparisons within assign

[andymikulski]

It appears that the assign operator doesn't like comparisons (i.e. [thing] contains [other thing]). For instance, I would expect this to work:

{%- assign is_some_product = variant.tags contains "example" -%}

But produces the error: Expected end_of_string but found comparison in [...]

I've used the following as a workaround:

{% if variant.tags contains "example" %}
  {%- assign is_some_product = true -%}
{% else %}
  {%- assign is_some_product = false -%}
{% endif %}

While the latter works, the former is much more concise and is what I would expect to work. Note that I found this while trying to use the or operator as well, but seeing as comparisons themselves aren't accepted, I don't think the parser even got that far.

---

edit 10/30/2020: The following snippet also works and is a bit more compact:

{%- assign is_some_product = false -%}
{% if variant.tags contains "example" %}
  {%- assign is_some_product = true -%}
{% endif %}

[shopmike]

Hey, @andymikulski I agree this is would be a cool addition to Liquid. There are a lot of things we are currently working on but would love to think this will make it in one day.

If someone is willing to take a crack at a pull request in the meantime I'm happy to review it.

For a bit of direction
https://github.com/Shopify/liquid/blob/master/lib/liquid/tags/assign.rb#L25
Variable.new needs to be able able to handle Conditions
https://github.com/Shopify/liquid/blob/master/lib/liquid/condition.rb

[torian257x]

one wonders a bit what went wrong that this isn't standard... security is the issue I assume?

[msangel]

@shopmike wrote:

Variable.new needs to be able able to handle Conditions

The same should be applied to printing out variables: {{ 99 > 98 }} should return true or false or anything better than 99 in lax mode and an exception in strict mode.
Related report: bkiers/Liqp#267