undefined.empty? is not true or false

[mikebridge]

I don't understand why this test is not returning "false":

    assert_template_result('else',
      '{% case a.empty? %}{% when true %}true{% when false %}false{% else %}else{% endcase %}',
      {})

The test is asserting that it's neither true nor false. Shouldn't this eval to false since nil != empty....?

[pushrax]

a is not defined, so its value is nil. nil does not have an empty? property, so the result of the whole keypath is nil, which doesn't match any of the cases so the else is hit.

It's a weird test though, since empty? is not actually a thing in Liquid (unless you expose it specifically in a drop or hash).

[mikebridge]

@pushrax Ah, so you're saying that the case statement does not actually compare based on truthiness, correct? I see that the following does not use truthiness as a basis for comparison either:

    {% case nil %}{% when false %}FALSE{% when true %}TRUE{%else%}NOT TRUE OR FALSE{% endcase %}
    --> NOT TRUE OR FALSE

    {% case 0 %}{% when true %}TRUE{% when false %}FALSE{%else%}NOT TRUE OR FALSE{% endcase %}
    --> NOT TRUE OR FALSE

Without knowing that, I would have expected those to return "FALSE" and "TRUE", respectively....

[pushrax]

It works similarly to ruby when using equality rather than truthiness (in ruby nil != false).

[mikebridge]

Ok, thanks for the clarification!