Markdown to return html string instead of just markdown

[Light2Dark]

📝 Summary

Closes #7931. markdown format to return html text instead of markdown text. This still is an improvement over the old behaviour before this PR #6464

before

In order to make ^ work, we need to use .text. With this PR, we don't need to do that anymore

after

🔍 Description of Changes

📋 Checklist

• I have read the contributor guidelines.
• For large changes, or changes that affect the public API: this change was discussed or approved through an issue, on Discord, or the community discussions (Please provide a link if applicable).
• Tests have been added for the changes made.
• Documentation has been updated where applicable, including docstrings for API changes.
• Pull request title is a good summary of the changes - it will be used in the release notes.

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Project	Deployment	Review	Updated (UTC)
marimo-docs	Ready	Preview, Comment	Jan 23, 2026 1:49pm

[Copilot]

Pull request overview

This PR fixes issue #7931 where mo.as_html(mo.md(...)) was not working as expected - it was rendering raw markdown text instead of formatted HTML when embedded in HTML templates.

Changes:

• Modified _md.__format__() to return rendered HTML (self.text) instead of raw markdown text (self._markdown_text)
• Updated existing test to reflect the new behavior
• Added comprehensive test coverage for various nesting scenarios with markdown and HTML
• Extended smoke tests with extensive edge cases for nested markdown and HTML combinations

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
marimo/_output/md.py	Changed __format__ method to return rendered HTML instead of raw markdown, fixing the embedding issue
tests/_output/test_hypertext.py	Updated test docstrings and assertions to match new behavior; added comprehensive tests for md-in-html, html-in-md, and various nesting scenarios
marimo/_smoke_tests/markdown/codeblocks.py	Added extensive manual test cases covering edge cases for nested markdown/HTML, code blocks, tables, lists, and various combinations

---

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[Copilot]

Missing space around assignment operator. Python style guidelines (PEP 8) recommend spaces around assignment operators for readability.

Suggested change

	code_block=mo.md("""
	code_block = mo.md("""

[ffmiruz]

looks like nested mo.md() results in nested html

inner = md("**bold**")
outer = md(f"Text: {inner}")
print(f"Nested mo.md: {outer.text}")

Nested mo.md: <span class="markdown prose dark:prose-invert contents"><span class="paragraph">Text: <span class="markdown prose dark:prose-invert contents"><span class="paragraph"><strong>bold</strong></span></span></span></span>

expected:

Nested mo.md: <span class="markdown prose dark:prose-invert contents"><span class="paragraph">Text: <strong>bold</strong></span></span>

[Light2Dark]

looks like nested mo.md() results in nested html

inner = md("**bold**")
outer = md(f"Text: {inner}")
print(f"Nested mo.md: {outer.text}")

Nested mo.md: <span class="markdown prose dark:prose-invert contents"><span class="paragraph">Text: <span class="markdown prose dark:prose-invert contents"><span class="paragraph"><strong>bold</strong></span></span></span></span>

expected:

Nested mo.md: <span class="markdown prose dark:prose-invert contents"><span class="paragraph">Text: <strong>bold</strong></span></span>

Good catch @ffmiruz , that used to work better when __format__ just returned _markdown_text 🤔

I guess in the current state, if users want HTML string, call .text
if want the markdown text, just f"mo.md(...)" is fine. So it is more flexible. However, this does differ in the approach for mo.Html where __format__ returns .text

[ffmiruz]

looks like nested mo.md() results in nested html

inner = md("**bold**")
outer = md(f"Text: {inner}")
print(f"Nested mo.md: {outer.text}")

Nested mo.md: <span class="markdown prose dark:prose-invert contents"><span class="paragraph">Text: <span class="markdown prose dark:prose-invert contents"><span class="paragraph"><strong>bold</strong></span></span></span></span>

expected:

Nested mo.md: <span class="markdown prose dark:prose-invert contents"><span class="paragraph">Text: <strong>bold</strong></span></span>

Good catch @ffmiruz , that used to work better when __format__ just returned _markdown_text 🤔

I guess in the current state, if users want HTML string, call .text if want the markdown text, just f"mo.md(...)" is fine. So it is more flexible. However, this does differ in the approach for mo.Html where __format__ returns .text

Haha yea the price to pay so we can embed. What do you think about doing this #7931 (comment)?

[Light2Dark]

@ffmiruz that doesn't solve the original issue the PR tried to solve which was nested code blocks in markdown losing their formatting

_code_block = mo.md("""
```python
def add(x: int, y: int):
    return x + y
```
""")

mo.md(f"""
**Nested code block**
{_code_block}
""")