if tag condition, the token args is empty after updating from 10.19.1 to 10.20.0 or later

[sidneyprins]

Hello,

We have a string

• Hello, {% if name %} {{ name }} {% else %} user {% endif %}

When we update from 10.19.1 to 10.20.0 or later, our test starts to fail. We use the LiquidJS engine to read out all the different kinds of tokens and figure out which are required and optional.

The token if normally gets args filled with name in this case, but since updating it returns an empty string.

Version 10.19.1

See args

Version 10.20.0 or higher

See args

I have done some digging and found these changes.

Link:
File tags/if.ts, line 15 till 21

If I revert these changes, it works again.

When I run that specific function item.token.tokenizer.readFilteredValue() I get the following error.

invalid value expression: "", line:1, col:18
>> 1| Hello, {% if name  %} {{ name }} {% else %} user {% endif %}
                       ^
TokenizationError: invalid value expression: "", line:1, col:18
    at Tokenizer.error (/private/var/www/vhosts/mailer/node_modules/liquidjs/dist/liquid.node.js:1999:16)
    at Tokenizer.assert (/private/var/www/vhosts/mailer/node_modules/liquidjs/dist/liquid.node.js:2003:24)
    at Tokenizer.readFilteredValue (/private/var/www/vhosts/mailer/node_modules/liquidjs/dist/liquid.node.js:1841:14)
    at eval (eval at <anonymous> (/private/var/www/vhosts/mailer/server/src/lib/helpers/liquid_helpers.ts:25:1), <anonymous>:1:22)
...

We have tried various versions of writing the strings, such as seen on https://liquidjs.com/tags/if.html, like

• {% if customer.name == "kevin" %} blabla {% endif %}

We're not sure how to make a fix for this part, can you help us?

[jg-rp]

Hi @sidneyprins,

args was removed in version 10.20.0 and an arguments() methods was introduced, which returns a Value | ValueToken iterable (not all tags implement arguments(), it is optional).

@harttle might be willing to reintroduce args, but you might find some of the built-in static analysis features to be a useful alternative.

In this example globalFullVariablesSync returns an array of variable names that are not in scope from previous or enclosing tags.

import { Liquid } from "liquidjs";

const liquid = new Liquid();

const exampleTemplate = `\
Hello, {% if name %} {{ name }} {% else %} user {% endif %}

{%- assign you = 'Liquid' %}
G'day, {% if you %}{{ you }}{% else %}there{% endif %}!
`;

const context = {
  name: "World",
};

const template = liquid.parse(exampleTemplate);
console.log(liquid.globalFullVariablesSync(template)); // [ 'name' ]

[jg-rp]

Ah, sorry. IfTag.token.args has not been removed, but we do now advance TagToken.tokenizer.p, which breaks TagToken.args. So this might be a bug worth fixing after all.

[github-actions]

🎉 This issue has been resolved in version 10.20.3 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot 📦🚀

[harttle]

Thank you for the investigation @jg-rp, I released a fix just now @sidneyprins . Please let me know if args is still not working for 10.20.3

[sidneyprins]

Thanks for making a fix, issue is resolved!