Markdown serialization does not preserve escaped blocks after round-trip

[olfusitus]

Affected Packages

markdown

Tiptap Version

3.29.1

Browser Used

Not browser-specific

What happened?

Description

Escaped block syntax is parsed correctly as paragraph text, but loses the required escape on serialization.

Reproduction

In the full Markdown demo, enter:

\# not a heading

1\. not a list

1. Click Parse Markdown
   -> Both lines correctly appear as paragraph text.
2. Click Extract Markdown
   -> Extracted Markdown is

# not a heading

1. not a list

3. Click Parse Markdown again
   -> The first line becomes a heading and the second line becomes a list item.

The same round-trip issue also affects other escaped blocks, including \-, \+, \---, Setext Headings and GFM table pipes.

Expected Behavior

The parse, serialize, parse round-trip should preserve the document structure.

Reproducible Example URL (Optional)

No response

Additional Context (Optional)

No response

[coderabbitai]

🔗 Related PRs

#7984 - fix(extension-blockquote): fix backspace getting blocked after merging [open]
#8008 - fix(markdown): recover blank lines absorbed into block token raw [merged]
#8012 - Fix (extension-table): line breaks in table cells no more get lost when serializing to markdown [merged]
#8017 - fix(markdown): never parse to an empty document (fixes setContent crash) [open]
#8111 - fix(markdown): keep non-breaking-space-only content instead of serializing to empty (#7495) [open]

---

📝 Issue Planner

_{Check the box below or use the @coderabbitai plan command to generate an implementation plan and prompts that you can use with your favorite coding assistant.}

• Create Plan

---

🧪 Issue enrichment is currently in open beta.

You can configure auto-planning by selecting labels in the issue_enrichment configuration.

To disable automatic issue enrichment, add the following to your .coderabbit.yaml:

issue_enrichment:
  auto_enrich:
    enabled: false

💬 Have feedback or questions? Drop into our discord!