How to maintain whitespaces in for-loops

[HenrikPoulsen]

Hello.
I'm working on something where I need to parse yaml files that use liquid. I have done some experimentation with liquidjs but I pretty quickly got into a situation where it seems to clobber leading whitespaces, which ends up making it invalid yaml.
Here's a simplified example:

await engine.parseAndRender(`
dependencies:
    - a hardcoded thing
{% for thing in things -%}
    - {{ thing }}
{% endfor -%}
    `, {things: [1, 2, 3, 4]})

The expected output here is:

 dependencies:
     - a hardcoded thing
     - 1
     - 2
     - 3
     - 4

but it becomes

dependencies:
    - a hardcoded thing
- 1
- 2
- 3
- 4

Here's an example using the playground which shows the same.
How can I avoid this behavior without requiring people to change their yml?
Is this a bug or can I configure this somehow?

[harttle]

The behavior of - is hard to understand even for me. There're greedy options to twick it a bit. Try that!

[pdehaan]

How about {%- instead of -%}?

{% assign things = "alice, bob, carol" | split: ", " -%}

dependencies:
    - a hardcoded thing
{%- for thing in things %}
    - {{ thing }}
{%- endfor %}

OUTPUT (from playground)

dependencies:
    - a hardcoded thing
    - alice
    - bob
    - carol

Only other idea I had was don't use {%- or -%} and just have some regexp or something that removes empty lines of whitespace on the rendered YAML output, but that feels risky.