{% octicon pulse width:32 height:32 viewBox:xxx aria-label:pulse %}
it's not work.

no viewBox option?
Tks!

It's hard to tell what works and what doesn't. For instance, simple expressions in the positional name argument {% octicon {{ foo.bar }} %} seem to work, but anything more complicated doesn't. Attributes are even tricker. I've never gotten this to work, for instance:

{% octicon file-directory class:"fill-{{ color }}" %}

Instead, I've resorted to some awful hacks to work around a failure to interpolate values from the "outer" Liquid context:

{% capture octo %}{% octicon file-directory class:"fill-${COLOR}" %}{% endcapture %}
{{ octo | replace: "${COLOR}", color }}

I'm not totally sure what's happening here, but I think that what we could do is interpolate the whole @markup string instead of the icon name and attributes separately, then parse the resulting value. So there'd be an intermediary step in rendering the tag when we'd convert something like:

{% octicon {{ name }} class="fill-{{ color }}" height:{{ height }} %}

to:

{% octicon file-directory class:"fill-green" height:20 %}

This would be a good chance to write some more robust tests.