Ensure heading only occurs once?

[adam-vest]

Hello folks! This is a continuation of #909 - I eventually landed on this setup for detecting the existence of exactly one header:

extends: occurrence
message: "Problem description heading does not occur exactly once"
ignorecase: true
scope: raw
level: error
min: 1
max: 1
token: "problem description</h[1-9]>"

However, this rule is specific to HTML, and in my environment, Markdown is also used. Is there a way with Vale to scan the entire document and ensure that one (and only one) occurrence of a heading is present? Without writing two separate rules for this (one for HTML, one for markdown)? I've been reading over the docs and trying to find some way to accomplish this, but nothing is presenting itself. The occurrence extension is far too specific, and the existence extension doesn't support min/max.

Thanks in advance!

[daobrien]

You might find that Vale only performs its checks after it's converted the content to HTML anyway, so it shouldn't matter if you use markdown or XML or whatever. Have you tested your rule on Markdown?

[adam-vest]

@daobrien , thanks for the reply! I had already tried it anyway, and it unfortunately triggers:

:~$ vale Documents/example.md 

 Documents/example.md
 1:1     error    Problem description heading     Mine.26a-kb-heading-problem-description 
                  does not occur exactly once                                                  

:~$ head -n1 Documents/example.md
# Problem description