Array comparisons (`in` and `==`) do not conform to TwigPHP

[dorian-marchal]

in operator doesn't work like Twig PHP when comparing arrays

For example, this evaluates to "true" with Twig PHP but "false" with twig.js:

{{ ["foo", "bar"] in [['foo', 'bar'], ['qux', 'baz']] ? 'true' : 'false' }}

This falls in this test:

twig.js/src/twig.expression.operator.js

Lines 20 to 23 in 788437f

	if (b.indexOf !== undefined) {
	// String
	return (a === b || a !== '') && b.indexOf(a) > -1;
	}

indexOf is not undefined for arrays.

Also, == operator is broken with array (it only seems to compare array lengths):

{{ ['foo'] == ['bar'] ? 'true' : 'false' }}

Evaluates to "true" with twig.js but "false" with Twig PHP.

This time, I think the corresponding code is here:

twig.js/src/twig.expression.operator.js

Lines 170 to 178 in 788437f

	if (operator !== 'in' && operator !== 'not in' && operator !== '??') {
	if (a && Array.isArray(a)) {
	a = a.length;
	}
	if (b && Array.isArray(b)) {
	b = b.length;
	}
	}

[ericmorand]

Twig.js doesn't support Twig comparison rules. They are quite complex (and arguably debatable) because Twig inherits them from PHP.

[dorian-marchal]

OK, I understand.

To me this is not only a compatibility issue between Twig JS and Twig PHP.
This kind of array comparison helps to write more concise templates:

{# For example: #}
{% if [country, city, place] in [
  ["France", "Paris", "Palais de l'Élysée"],
  ["Germany", "Berlin", "Federal Chancellery"],
  ...
] %}
    Official residence
{% endif %}

{# instead of: #}
{% if
    (country == "France" and city == "Paris" and place == "Palais de l'Élysée")
    or (country == "Germany" and city == "Berlin" and place == "Federal Chancellery")
    ...
%}
    Official residence
{% endif %}

I suppose I could give an other try to Twing but it is really heavy and I need it on client side.

[willrowe]

• TwigPHP example
• twig.js example