white space control in jekyll - why does {%- ... -%} a la liquid not work? : <p>The <a href="https://help.shopify.com/themes/liquid/basics/whitespace" rel="noreferrer">liquid documentation</a> states that </p>

<blockquote>
  <p>By including hyphens in your assign tag, you can strip the generated whitespace from the rendered template ... if you don't want any of your tags to output whitespace, as a general rule you can add hyphens to both sides of all your tags ({%- and -%}):</p>
</blockquote>

<p>When I try in jekyll</p>

<pre><code>{%- case key -%}
</code></pre>

<p>I get the error</p>

<pre><code>Error: Liquid syntax error (line 139): Tag '{%- case key -%}' was not
properly terminated with regexp: /\%\}/
</code></pre>

<p>There are many posts about excessive whitespace in the jekyll generated html, for example <a href="https://www.sylvaindurand.org/compressing-liquid-generated-html/" rel="noreferrer">Compressing Liquid generated code</a>.</p>

<p>They all complain about dilute HTML output and discuss plug-ins as solution.
My simple questions are:</p>

<ol>
<li>Why does <code>{%- ... -%}</code> not work in jekyll ?</li>
<li>Why behaves jekyll differently than the liquid documentation suggests</li>
</ol>
