We could write a library of books detailing Shopify's bad designs, incomplete product and broken practices. But this simple issue probably deserves some kind of award.
In the liquid template, the following code works:
<% if "abc" == "abc" %>
ABC
<% endif %>
However, when the spaces around the == operator are removed, which is acceptable in ANY sane language, the condition is no longer triggered.
<% if "abc"=="abc" %>
ABC
<% endif %>
There is also no syntax error or warning of any kind.
Shopify is aware of this issue and is unlikely to address this bug that was reported in 2015.