Annotations in class diagram not working with SuperFences

Source:

classDiagram
  class Foo
  <<abstract>> Foo

Expected:

classDiagram
  class Foo
  <<abstract>> Foo

Actual:

Here’s the mkdocs.yml, if I disable SuperFences it works as expected.

site_name: Test

docs_dir: docs

plugins:
  - mermaid2

markdown_extensions:
  - pymdownx.superfences:
      custom_fences:
        - name: mermaid
          class: mermaid
          format: !!python/name:mermaid2.fence_mermaid

mkdocs==1.3.1 mkdocs-mermaid2-plugin==0.6.0 pymdown-extensions==9.5

[guansss]

It turns out that the annotations are half escaped, resulting in unexpected HTML tag that breaks Mermaid parser:

I looked into the source of fence_mermaid formatter and the comment says it does not escape the Mermaid source, so I switched to the official formatter superfences.fence_div_format (which does escape) and then everything worked without problem.

  - pymdownx.superfences:
      custom_fences:
        - name: mermaid
          class: mermaid
          format: !!python/name:pymdownx.superfences.fence_div_format

Looks like escaping the source is necessary? Then I’m wondering, what was the original purpose of not to escape? Does escaping have pitfalls?

[guansss]

Oh I missed that part. Thanks for the answer!

Perhaps I should document this better?

That’ll be good. 👍 Maybe also suggest user to manually escape these symbols (e.g. <<abstract>>) as a workaround in loose mode.